fbpx
Wikipedia

Cataract surgery

December 15, 2023

Cataract surgery, also called lens replacement surgery, is the removal of the natural lens of the eye that has developed a cataract, an opaque or cloudy area.[1] The eye's natural lens is usually replaced with an artificial intraocular lens (IOL) implant.[2]

Cataract surgery
Cataract surgery, using a temporal approach phacoemulsification probe (in right hand) and "chopper" (in left hand)
SpecialtyOphthalmology
ICD-9-CM13.19
MeSHD002387
MedlinePlus002957
[edit on Wikidata]

Over time, metabolic changes of the crystalline lens fibres lead to the development of a cataract, causing impairment or loss of vision. Some infants are born with congenital cataracts, and environmental factors may lead to cataract formation. Early symptoms may include strong glare from lights and small light sources at night and reduced visual acuity at low light levels.[3][4]

During cataract surgery, the cloudy natural lens is removed from the posterior chamber, either by emulsification in place or by cutting it out.[2] An IOL is usually implanted in its place (PCIOL), or less frequently in front of the chamber, to restore useful focus. Cataract surgery is generally performed by an ophthalmologist in an out-patient setting at a surgical centre or hospital. Local anaesthesia is normally used; the procedure is usually quick and causes little or no pain and minor discomfort. Recovery sufficient for most daily activities usually takes place in days, and full recovery about a month.[5]

Well over 90% of operations are successful in restoring useful vision, and there is a low complication rate. Day care, high-volume, minimally invasive, small-incision phacoemulsification with quick post-operative recovery has become the standard of care in cataract surgery in the developed world.[2] Manual small incision cataract surgery (MSICS), which is considerably more economical in time, capital equipment, and consumables, but provides comparable results, is popular in the developing world.[6] Both procedures have a low risk of serious complications,[7][8] and are the definitive treatment for vision impairment due to lens opacification.[9]

Uses edit

See also: Cataract
 
Magnified view of a cataract seen on examination with a slit lamp

Cataract surgery is the most common application of lens removal surgery, and is usually associated with lens replacement. It is used to remove the natural lens of the eye when it has developed a cataract, a cloudy area in the lens that causes visual impairment.[4][10] Cataracts usually develop slowly and can affect one or both eyes.[4] Early symptoms may include faded colours, blurred or double vision, halos around lights, sensitivity to glare from bright lights, and night blindness. Blindness is the end result.[4] The procedure is normally elective, but lens removal may be part of trauma surgery in cases where the eye is severely injured. The lens is usually replaced by an intraocular implant when this is reasonably practicable, as removal of the lens also removes the ability of the eye to focus at any distance.[2]

Cataracts most commonly occur due to aging, but may also be caused by trauma or radiation exposure, be present since birth, or may develop as a complication of eye surgery intended to solve other health problems.[4][11] Cataracts form when clumps of proteins or yellow-brown pigment accumulate in the lens, which reduces transmission of light to the retina at the back of the eye.[4] Cataracts can be diagnosed via an eye examination.[4]

Early symptoms of cataract may be improved by wearing specific types of glasses; if this does not help, cataract surgery is the only effective treatment.[4] Surgery with implants generally results in better vision and an improved quality of life: however, the procedure is not readily available in many countries.[4][11][12][13]

Techniques edit

 
Cataract surgery using a surgical microscope
 
Cataract surgery recently performed, foldable IOL inserted. A small incision and very slight hemorrhage are visible to the right of the still dilated pupil.
 
Nucleus of a mature cataract removed by ECCE

Two main classes of cataract surgical procedures are currently in common use throughout the world: phacoemulsification, and extracapsular cataract extraction. Intracapsular cataract extraction has been superseded where the facilities for surgery under a microscope are available except for cases where the lens capsule cannot be retained, and couching is no longer used in mainstream medicine.

In phacoemulsification (phaco), the natural lens is fragmented by an ultrasonic probe and removed by suction. A more recent and less common variation of this, Femtosecond laser-assisted phacoemulsification surgery, uses a laser to make the corneal incision, execute the capsulotomy, which provides access to the lens, and initiate lens fragmentation, which reduces energy requirements for phacoemulsification.[7] The small incision size used in phacoemulsification generally allows for sutureless incision closure.[7]

In extracapsular cataract extraction (ECCE), and its variation manual small incision cataract surgery (MSICS), the lens is removed from its capsule and manually extracted from the eye, either whole or after being split into a small number of substantial pieces.[9] The basic version of ECCE uses a larger incision of 10–12 mm (0.39–0.47 in) and usually requires stitches. This requirement led to the variation known as MSICS, which does not usually need stitches as the incision should be self sealing under internal pressure due to its geometry.[2] Comparative trials of MSICS against phaco in dense cataracts have found no significant difference in outcomes, although MSICS had shorter operating times and significantly lower costs.[6] MSICS has been prioritized as the method of choice in developing countries, because it provides high-quality outcomes with less surgically-induced astigmatism than standard ECCE, no suture-related problems, quick rehabilitation, and fewer post-operative visits. MSICS is generally easy and fast to learn for the surgeon, cost-effective and applicable to almost all types of cataract.[8] ECCE using a large incision has largely become a contingency procedure to deal with complications during surgery and for managing cataracts expected to be difficult extractions.[14]

In most surgeries, an IOL is inserted. Foldable lenses are generally used for the 2–3 mm (0.08–0.12 in) phaco incision, while non-foldable lenses can be placed through the larger extracapsular incision.

Intracapsular cataract extraction (ICCE) is the removal of the lens and the surrounding lens capsule in one piece. The procedure has a relatively high rate of complications in comparison to techniques in which the capsule is retained in place, due to the large incision required, pressure placed on the vitreous body when removing the encapsulated lens, and the removal of the barrier between the chambers of the eye, allowing easier migration of vitreous into the anterior chamber. It has therefore been largely superseded and is rarely performed in countries where operating microscopes and high-technology equipment are readily available.[2] After lens removal by ICCE, an intraocular lens implant can be placed in either the anterior chamber or sutured into the ciliary sulcus.[Note 1][7] Cryoextraction is a technique used in ICCE to extract the lens using a cryoprobe, the refrigerated tip of which adheres to the tissue of the lens at the contact point by freezing with a cryogenic substance such as liquid nitrogen, facilitating its removal.[15] Cryoextraction may still be used for the removal of subluxated (partially dislocated) lenses.[16]

Couching is the earliest documented form of cataract surgery. It involves dislodging the lens of the eye, removing the cataract from the optical axis, but leaving it inside the eye. The lens is not replaced and the eye cannot focus at any distance.[17]

Phacoemulsification is the most commonly performed cataract procedure in the developed world,[18] but the high capital and maintenance costs of a phacoemulsification machine and of the associated disposable equipment, have made ECCE and MSICS the most commonly performed procedures in developing countries.[2] Cataract surgery is commonly done as an out-patient or day-care procedure, which is cheaper than hospitalisation and an overnight stay, and day surgery has similar medical outcomes.[19]

Pre-operative evaluation edit

An eye examination or pre-operative evaluation is done to confirm the presence of a cataract and to determine the patient's suitability for surgery:[2]

  • The degree of reduction of vision due largely to the cataract is evaluated. While the existence of other sight-threatening diseases, such as age-related macular degeneration or glaucoma, does not preclude cataract surgery, less improvement may be expected in their presence.[2]
  • In cases of uncontrolled glaucoma, a combined cataract-glaucoma procedure (phaco-trabeculectomy) can be planned and performed.[20]
  • The pupil is checked for dilation using eyedrops; if pharmacologic pupil dilation is insufficient, procedures for mechanical pupil dilatation may be needed during the surgery.[21]
  • People with retinal detachment may be scheduled for a combined vitreo-retinal procedure, along with IOL implantation.[22]
  • People taking tamsulosin (Flomax), a common drug for enlarged prostate, are prone to developing a surgical complication known as intraoperative floppy iris syndrome (IFIS), which requires appropriate management to avoid posterior capsule rupture;[Note 2][23]
  • A Cochrane Review of three randomized clinical trials, including over 21,500 cataract surgeries, examined whether routine pre-operative medical testing resulted in a reduction of adverse events during surgery. Results showed performing pre-operative medical testing did not result in a reduction of risk of intra-operative or post-operative medical adverse events, compared to surgeries with no or limited pre-operative testing.[24]
  • Infants with congenital cataracts are more likely to have post-operative inflammation problems,[25] and their eyes grow rapidly and unpredictably, making it challenging to select and fit a posterior chamber IOL in infants younger than seven months that will give satisfactory results later in childhood. A second surgery may be required later.[26]

Contraindications edit

Contraindications to cataract surgery include cataracts that do not cause visual impairment and medical conditions that predict a high risk of unsatisfactory surgical outcomes.[2] such as:

  • Poor general health or a serious medical condition.[27]
  • Surgery will not provide better visual function.[28]
  • Advanced macular degeneration[27]
  • Detached retina.[27]
  • Advanced diabetes that has affected the retina.[27]
  • An infection of the eyes or nearby that could cause endophthalmitis, so should be treated before cataract surgery.[28]
  • The person does not want surgery.[28]
  • Functional vision can be provided by glasses or other visual aids which is sufficient for the person's requirements.[28]
  • Corneal diseases such as glaucoma may be a relative contraindication.[27]

Selection of intraocular lenses edit

Main article: Intraocular lens
 
18.5 diopter foldable intraocular lens
 
Injector for foldable intraocular lenses. The incision size for this type is 2.8mm
 
The IOL injector is inserted in the incision and aimed at the capsule
 
The rolled up lens is ejected from the nozzle into the capsule
 
The lens unfolds in place
 
Section diagram of the eye, showing intraocular lens implanted in the posterior lens capsule behind the iris

After the removal of a cataract, an intraocular lens is usually implanted to replace the damaged natural lens. A foldable IOL may be implanted through a 1.8 to 2.8 mm (0.071 to 0.110 in) incision, whereas a rigid poly(methyl methacrylate) (PMMA) lens requires a larger cut. Foldable IOLs are made of silicone, hydrophobic, or hydrophilic acrylic material of appropriate refractive power and are inserted with a special tool.[29] The IOL is inserted through the incision, usually into the capsular bag from which the cararact was removed (in-the-bag implantation). Sometimes, a sulcus implantation—in front of the capsular bag, but behind the iris—may be required because of posterior capsular tears or zonular dialysis (inadequate support for the capsular bag). This requires an IOL with different refractive power because of the placement further forward on the optical axis.[30]

The appropriate refractive power of the IOL is selected, much like a spectacle or contact lens prescription, to provide the desired refractive outcome. Pre-operative measurements, including corneal curvature, axial length, and white-to-white measurements[Note 3] are used to estimate the required power of the IOL. These methods include several formulae and free online calculators which use similar input data.[31] A history of LASIK surgery, which alters corneal curvature, requires different calculations to take this into account.[31]

Monofocal IOLs provide accurately focused vision at one distance only; far, intermediate, or near. People who are fitted with these lenses may need to wear glasses or contact lenses while reading or using a computer. These lenses usually have uniform spherical curvature.[32]

Other designs of multifocal intraocular lens that focus light from distant and near objects, working with similar effect to bifocal or trifocal eyeglasses, are also available. Pre-operative patient selection and good counselling is necessary to avoid unrealistic expectations and post-operative patient dissatisfaction, and possibly a requirement to replace the lens.[33] Acceptability of these lenses has improved, and studies have shown good results in patients selected for expected compatibility.[34]

Cataract surgery may be performed to correct vision problems on both eyes. If both eyes are suitable, people are usually advised to consider monovision. This procedure involves inserting an IOL providing near vision into one eye, while using one that provides distance vision for the other eye. Although most people can adjust to having monofocal IOLs with differing focal length, some cannot compensate and may experience blurred vision at both near and far distances. An IOL optimised for distance vision may be combined with an IOL that optimises intermediate vision, instead of near vision, as a variation of monovision.[29]

One model of lens designed to change focus using the natural reflexes of the eye has two hinged struts on opposite edges, which displace the lens along the optical axis when an inward transverse force is applied to the haptic loops at the outer ends of the struts—the components transferring the movement of the contact points to the device—while recoiling when the same force is reduced. The lens is implanted in the eye's lens capsule, where the contractions of the ciliary body, which would focus the eye with the natural lens, are used to focus the implant, instead.[2][35]

IOLs used in correcting astigmatism have different curvature on two orthogonal axes, as on the surface of a torus: for this reason, they are called toric lenses. Intraoperative aberrometry[Note 4] can be used to assist the surgeon in toric lens placement and minimize astigmatic errors.[36][37]

The first aspheric IOLs were developed in 2004; they have a flatter periphery than the middle of the lens, improving contrast sensitivity. The effectiveness of aspheric IOLs depends on a range of conditions and they may not always provide significant benefit.[38]

Some IOLs are able to absorb ultraviolet and high-energy blue light, thus mimicking the functions of the natural crystalline lens of the eye, which usually filters potentially harmful frequencies. A 2018 Cochrane review found there is unlikely to be a significant difference in distance vision between blue-filtering and plain lenses, and was unable to identify a difference in contrast sensitivity or colour discrimination.[39][40]

The light-adjustable IOL was approved by the U.S. Food and Drug Administration (FDA) in 2017.[41] This type of IOL is implanted in the eye and then treated with ultraviolet light to alter the curvature of the lens before fixing it at the final strength.[42]

In some cases, it may be necessary or desirable to insert an additional lens over the already implanted one, also in the posterior capsule. This type of IOL placement is called "piggyback" IOLs and is usually considered when the visual outcome of the first implant is not optimal.[43] In such cases, implanting another IOL over the existing one is considered safer than replacing the initial lens. This approach may also be used in people who need high degrees of vision correction.[44]

Cost is an important aspect of these lenses. Although Medicare covers the cost of monofocal IOLs in the United States, people will have to pay the price difference if they choose more expensive lenses.[45]

Operation procedures edit

Preparation edit

Preparation may begin three-to-seven days before surgery, with the pre-operative application of NSAIDs and antibiotic eyedrops.[8] If the IOL is to be placed behind the iris, the pupil is dilated by using drops to help better visualise the cataract. Pupil-constricting drops are reserved for secondary implantation of the IOL in front of the iris, when the cataract has already been removed without primary IOL implantation.[46]

The operation may occur on a stretcher or a reclining examination chair. The eyelids and surrounding skin are swabbed with a disinfectant, such as 10% povidone-iodine, and topical povidone-iodine is applied to the eye. The face is covered with a cloth or sheet with an opening for the operative eye. The eyelid is held open with a speculum to minimize blinking during surgery.[47] Pain is usually minimal in properly anaesthetised eyes, though a pressure sensation and discomfort from the bright operating microscope light is common.[7]

Anaesthesia edit

Most cataract operations are performed under local anaesthetic, allowing the patient to return home the same day. Lens and cataract procedures are commonly performed in an out-patient setting; in the United States, 99.9% of lens and cataract procedures were done in an out-patient setting by 2012.[48]

Topical, sub-tenon, peribulbar, or retrobulbar local anaesthesia is generally used, usually causing little or no discomfort.[49][46] Injections may be used to block regional nerves and prevent eye movement.[7] Topical anaesthetics are most commonly used, placed on the globe of the eye as eyedrops (before surgery), or in the globe (during surgery).[46] Oral or intravenous sedation to reduce anxiety may be combined with the local anaesthetic. General anaesthesia and retrobulbar blocks were historically used for intracapsular cataract surgery, and may be used for children and adults whose medical or psychiatric issues significantly affect their ability to remain still during the procedure.[7][46]

Phacoemulsification edit

Main article: Phacoemulsification

Phacoemulsification uses a machine with an ultrasonic handpiece with a titanium or surgical stainless steel tip, which vibrates at an ultrasonic frequency—commonly 40 kHz—to emulsify the lens tissue, which is aspirated by a coaxial annular suction tube. A second instrument, which is sometimes called a "cracker" or "chopper", may be used from a small side incision to break the hard cataract nucleus into smaller pieces, making emulsification and removal of the soft part of the lens around the nucleus easier. After phacoemulsification of the lens nucleus and cortical material is completed, an irrigation–aspiration (I-A) system is used to remove the remaining peripheral lens material. The procedure is done under a surgical microscope.[7]

Femtosecond laser-assisted phacoemulsification surgery is a more recent development which may have fewer adverse effects on the cornea and macula than manual phacoemulsification. The laser is used to make the corneal incision and the capsulotomy, which provides access to the lens, and initiate lens fragmentation, which reduces energy requirements for phacoemulsification. It offers high-precision, effective lens fragmentation at lower power levels and good optical quality. However, as of 2022, the technique has not been shown to have significant visual, refractive, or safety benefits over manual phacoemulsification, and it has a higher cost.[2][50][51]

Entry into the eye is made through a minimal tunnel incision near the edge of the cornea.[7] The incision for cataract surgery has evolved along with the techniques for cataract removal and IOL placement. In phacoemulsification, the width depends on the requirements for IOL insertion. With foldable IOLs, it is often possible to use incisions smaller than 3.5 mm (0.14 in). The shape, position, and size of the incision affect the capacity for self sealing, the tendency to induce astigmatism, and the surgeon's ability to maneuvre instruments through the opening.[52] A more-posterior incision simplifies wound closure and decreases induced astigmatism, but it is more likely to damage blood vessels nearby. [7] One or two smaller side-port incisions at 60-to-90 degrees from the main incision may be needed to access the anterior chamber with additional instruments.[47]

Ophthalmic viscosurgical devices (OVDs), a class of clear, gel-like materials, are injected into the anterior chamber at the start of the procedure, to support, stabilize, and protect the eyeball, to help maintain eye shape and volume, and to distend the lens capsule during IOL implantation.[53] Their consistency allows surgical instruments to move through them, although they do not flow and retain their shape under low shear stress. The OVD will also constrain lens fragments from drifting around in the chamber. OVDs are available in several formulations, which may be combined or used individually as best suits the procedure.[7]

The lens is inside a capsule supported by the ciliary body, between the aqueous and vitreous, behind the opening in the iris. Capsulorhexis is the process of tearing a circular opening in the front membrane of the lens capsule to access the lens within. In phacoemulsification, an anterior continuous curvilinear capsulorhexis is usually used to create a round, smooth-edged opening through which the surgeon can emulsify the lens nucleus, and then implant the intraocular lens.[54]

The cataract's outer (cortical) layer is then separated from the capsule by a gentle, continuous flow or pulsed dose of liquid from a cannula, which is injected under the anterior capsular flap, along the edge of the capsulorhexis opening, in a step called hydrodissection.[55][56] In hydrodelineation, fluid is injected into the body of the lens through the cortex against the nucleus of the cataract, which separates the hardened nucleus from the softer cortex shell by flowing along the interface between them. As a result, the smaller hard nucleus can be more-easily emulsified. The posterior cortex serves as a buffer at this stage, protecting the posterior capsule membrane. The smaller size of the separated nucleus allows it to be broken up using shallower and less-peripheral grooving by the phaco tip, and produces smaller fragments after cracking or chopping. The posterior cortex also maintains the shape of the capsule through this stage, which reduces the risk of posterior capsule rupture.[57]

After nuclear cracking or chopping (if needed), the cataract is reduced to small fragments using ultrasound which are simultaneously aspirated. The remaining lens cortex (outer layer of lens) material from the capsular bag is carefully aspirated, and if necessary, the remaining epithelial cells from the capsule are removed by capsular polishing.[58] The folded intraocular replacement lens is implanted, usually into the remaining posterior capsule, and checked hat it has unfoldded and seated correctly. A toric IOL must also be aligned in the correct axis to counteract astigmatism.[2]

Manual small incision cataract surgery (MSICS) edit

Many of the steps followed during MSICS are similar, if not identical, to those for phacoemulsification; the main differences are related to the alternative method of incision and cataract extraction from the capsule and eye.

Manual small incision cataract surgery (MSICS) is an evolution of ECCE; the lens is removed from the eye through a self-sealing tunnel wound through the sclera. A well-constructed scleral tunnel is held closed by internal pressure, is watertight, and does not require suturing. The wound is relatively smaller than the one in ECCE, but is still markedly larger than a phaco wound.

The small incision into the anterior chamber of the eye is made at or near the corneal limbus, where the cornea and sclera meet, either superior or temporal.[8] Advantages of the smaller incision include use of few-to-no stitches and shortened recovery time.[2] The MSICS incision is small in comparison with the earlier ECCE incision, but considerably larger than the one used in phacoemulsification. The precise geometry of the incision is important, as it affects the self-sealing of the wound and the amount of astigmatism induced by distortion of the cornea during healing. A sclerocorneal or scleral tunnel incision is commonly used, since it reduces the risk of induced astigmatism if suitably formed.[6][47] A sclerocorneal tunnel, a three-phase incision, starts with a shallow incision perpendicular to the sclera, followed by an incision through the sclera and cornea approximately parallel to the outer surface, and then a beveled incision into the anterior chamber. This structure provides the self-sealing characteristic, because internal pressure presses together the faces of the incision.[8] Bridle sutures[Note 5] may be used to help stabilize the eyeball during sclerocorneal tunnel incision, and during extraction of the nucleus and epinucleus through the tunnel.[8] The depth of the anterior chamber and position of the posterior capsule may be maintained during surgery by OVDs or an anterior chamber maintainer, which is an auxiliary cannula providing a sufficient flow of buffered saline solution (BSS) to maintain stability of the shape of the chamber and internal pressure.[59][60] An anterior capsulotomy, is then done to open the front surface of the lens capsule for access to the lens.[61] The continuous curvilinear capsulorhexis technique is often used, or can-opener capsulotomy and envelope capsulotomy.[59]

The cataract lens is then removed from the capsule and anterior chamber using hydroexpression,[Note 6] viscoexpression,[Note 7] or more direct mechanical methods.[59][62][63] Following cataract removal, an IOL is usually inserted into the posterior capsule.[7] When the posterior membrane of the capsule is damaged, the IOL may be inserted into the ciliary sulcus,[30] or a glued intraocular lens technique may be applied.[64]

Extracapsular cataract extraction edit

Extracapsular cataract extraction (ECCE), also known as manual extracapsular cataract extraction, is the removal of almost the entire natural lens in one piece, while most of the elastic lens capsule (posterior capsule) is left intact to allow implantation of an intraocular lens.[2] The lens is manually removed through a 10–12 mm (0.39–0.47 in) incision in the cornea or sclera. Although it requires a larger incision and the use of stitches, this method may be preferable for very hard cataracts, which would require a relatively large ultrasonic energy input, which causes more heating, as well as in other situations in which phacoemulsification is problematic.[14]

Converting to ECCE to manage a contingency edit

The most commonly used procedures are phacoemulsification and manual small incision cataract surgery (MSICS). In either of these procedures, it can sometimes be necessary to convert to ECCS to deal with a problem better managed through a larger incision.[14] This may occur in the event of posterior capsule rupture, zonular dehiscence,[Note 8] a dropped nucleus[Note 9] with a nuclear fragment more than half the size of the cataract,[14] problematic capsulorhexis with a hard cataract,[14] or a very dense cataract where the heat developed by phacoemulsification is likely to cause permanent damage to the cornea.[14] Similarly, a change from MSICS to ECCE is appropriate whenever the nucleus is too large for the MSICS incision,[14] as well as in cases where the nucleus is found to be deformed during MSICS on a nanophthalmic eye.[Note 10][14]

Closing the wound edit

After the IOL is inserted, OVDs that were injected to stabilize the anterior chamber, protecting the cornea from damage and distending the cataract's capsule during IOL implantation, are removed from the eye to prevent post-operative viscoelastic glaucoma, a severe intra-ocular pressure increase. This is done via suction from the irrigation-aspiration instrument and replacement by buffered saline solution (BSS). Cohesive OVDs tend to adhere to themselves, a characteristic that makes their removal easier.[53] Removal of OVDs from behind the implant reduces the risk and magnitude of post-operative pressure spikes or capsular distention.[7] In the final step, the wound is sealed by increasing the pressure inside the globe with BSS, which presses the internal tissue against the external tissue of the incision, holding it closed. The surgeon will check whether the incision leaks fluid, because wound leakage increases the risk of penetration into the eye by microorganisms, thus predisposing it to endophthalmitis. If this does not achieve a satisfactory seal, a suture may be added. The wound is then hydrated, an antibiotic/steroid combination eyedrop is put in, and an eye-shield may be applied, sometimes supplemented with an eyepatch.[7]

Post-operative care edit

The use of an eye patch may be indicated, usually for some hours after surgery and for a few days while sleeping. A topical corticosteroid or nonsteroidal anti-inflammatory drug (NSAID) is used to control inflammation, in combination with topical antibiotics to prevent infection in the post-operative phase. These are generally self-administered as eyedrops for a few weeks.[7]

Complications edit

During surgery edit

Posterior capsular rupture, a tear in the posterior capsule of the natural lens, is the most common complication during cataract surgery, with its rate ranging from 0.5% to 5.2%.[2] Surgical management may involve anterior vitrectomy and occasionally, alternative planning for implanting the IOL, either in the ciliary sulcus (the space between the iris and the ciliary body}, in the anterior chamber in front of the iris, or less commonly, sutured to the sclera. Posterior capsule rupture can cause lens fragments to be retained, corneal oedema, and cystoid macular oedema; it is also associated with a six-times increase in the risk of endophthalmitis and as much as a nineteen-times increase in the risk of retinal detachment.[2][65] Management methods include the Intraocular lens scaffold procedure.[66]

Suprachoroidal hemorrhage is a rare complication of intraocular surgery, which occurs when damaged ciliary arteries bleed into the space between the choroid and the sclera.[67] It is a potentially vision-threatening pathology. Risk factors for suprachoroidal hemorrhage include anterior chamber intraocular lens (ACIOL), axial myopia, advanced age, atherosclerosis, glaucoma, systolic hypertension, tachycardia, uveitis and previous ocular surgery. Suprachoroidal hemorrhage must be treated immediately and effectively in order to preserve visual functions.[7]

Intraoperative floppy iris syndrome has an incidence ranging from around 0.5% to 2.0%.[2] Iris or ciliary body injury has an incidence of about 0.6%-1.2%.[2] In the event of a posterior capsule rupture, fragments of the nucleus can find their way through the tear into the vitreous chamber; this is called posterior dislocation of nuclear fragments. Recovery of the fragments is not always desirable and it is rarely successful. The rest of the fragments should generally be stabilised first, and vitreous needs to be prevented from entering the anterior chamber. Removal of the fragments may be best referred to a vitreoretinal specialist.[7]

Other complications include failure to aspirate all lens fragments, leaving some in the anterior chamber,[65] and incisional burns, caused by overheating of the phacoemulsification tip when ultrasonic power continues while the irrigation or aspiration lines are blocked—the flow through these lines is used to keep the tip cool. Burns to the incision may make closure difficult and can cause corneal astigmatism.[7]

After surgery edit

 
Slit lamp photo of IOL showing Posterior capsular opacification (PCO) visible a few months after implantation of intraocular lens in eye, seen on retroillumination

Complications after cataract surgery are relatively uncommon. Posterior vitreous detachment (PVD) does not directly threaten vision, but its cases are monitored with increasing interest, since the interaction between the vitreous body and the retina might play a decisive role in the development of major pathological vitreoretinal conditions. PVD may be more problematic with younger patients because many people older than 60 have already gone through PVD. PVD may be accompanied by peripheral light flashes and increasing numbers of floaters.[68]

Some people develop posterior capsular opacification (PCO), also called an "after-cataract". After cataract surgery, posterior capsular cells usually undergo hyperplasia and cellular migration as part of a physiological change, showing up as a thickening, opacification, and clouding of the posterior lens capsule, which is left behind after the cataract is removed, for placement of the IOL. This may compromise visual acuity, and can usually be safely and painlessly corrected by using a Nd:YAG laser to clear the central portion of the opacified posterior pole of the capsule (posterior capsulotomy).[69] This creates a clear central visual axis, which improves visual acuity.[70] In very thick opacified posterior capsules, a manual surgical capsulectomy might be needed. In the event of IOL replacement, a posterior capsulotomy could allow vitreous to migrate into the anterior chamber through the opening previously occluded by the IOL, and would have to be removed. Posterior capsule opacification has an incidence of about 0.3% to 28.4%.[2]

Retinal detachment normally occurs at a prevalence of 1 in 1,000 (0.1%); however, people who have had cataract surgery are at an increased risk (0.5–0.6%) of developing rhegmatogenous retinal detachment (RRD)—the most common form of the condition.[71] Cataract surgery increases the rate of vitreous humour liquefaction, which leads to increased rates of RRD.[72] When a retinal tear occurs, vitreous liquid enters the space between the retina and retinal pigment epithelium (RPE), and presents as flashes of light (photopsia), dark floaters, and loss of peripheral vision.[71] Toxic anterior segment syndrome (TASS), a non-infectious inflammatory condition, may also occur following cataract surgery: it is usually treated with topical corticosteroids in high dosage and frequency.[73]

Endophthalmitis is a serious infection of intraocular tissues, usually following intraocular surgery complications or penetrating trauma, and one of the most severe. It rarely occurs as a complication of cataract surgery, due to the use of prophylactic antibiotics, but there is some concern that the clear cornea incision might predispose to the increase of endophthalmitis, although no conclusive study has corroborated this suspicion.[74] An intracameral injection of antibiotics may be used as a preventive measure. A meta-analysis showed the incidence of endophthalmitis after phacoemulsification to be 0.092%. The risk gets higher in association with factors such as diabetes, advanced age, larger incision procedures,[29] and vitreous' communication with the anterior chamber caused by posterior capsule rupture. The risk of vitreous infection is at least six times higher than for the aqueous.[75] Endophthalmitis typically presents within two weeks after the procedure, with manifestations such as decreased visual acuity, red-eye and pain. Hypopyon occurs about 80% of the time. Common infective agents include coagulase-negative staphylococci and Staphylococcus aureus in about 80% of infections. Management includes vitreous humour tap and injection of broad-spectrum antibiotics. Outcomes can be severe even with treatment, and may range from permanently decreased visual acuity to the complete loss of light perception, depending on the microbiological etiology.[2]

Glaucoma may occur and may be very difficult to control. It is usually associated with inflammation, especially when fragments of the nucleus enter the vitreous cavity. Some experts recommend early intervention by posterior pars plana vitrectomy when this condition occurs. In most cases, raised post-operative intraocular pressure is transient and benign, usually returning to baseline within 24 hours without intervention. Glaucoma patients may experience further visual field loss or a loss of fixation, and are more likely to experience intraocular pressure spikes.[76] On the other hand, secondary glaucoma is an important complication of surgery for congenital cataracts: patients can develop this condition even several years after undergoing cataract surgery, so they need lifelong surveillance.[77]

Mechanical pupillary block manifests when the anterior chamber gets shallower as a result of the obstruction of the aqueous humour flow through the pupil by the vitreous face or IOL.[78] This is caused by contact between the edge of the pupil and an adjacent structure, which blocks the flow of aqueous through the pupil itself. The iris then bulges forward and closes the angle between the iris and cornea, blocking drainage through the trabecular meshwork and causing an increase in intraocular pressure. Mechanical pupillary block has mainly been identified as a complication of anterior chamber intraocular lens implantation, but has been known to occur occasionally after posterior IOL implantation.[79]

Occasionally, a peripheral iridectomy may be made to minimize the risk of pupillary block glaucoma.[7] Surgical iridectomy can be done manually or with a Nd:YAG laser. Laser peripheral iridotomy may be done either before or following cataract surgery.[80]

Swelling of the macula, the central part of the retina, results in macular oedema and can occur a few days or weeks after surgery. Most such cases can be successfully treated. Preventative use of nonsteroidal anti-inflammatory drugs has been reported to reduce the risk of macular oedema to some extent.[81]

Uveitis–glaucoma–hyphema syndrome is a complication caused by the mechanical irritation of a mis-positioned IOL over the iris, ciliary body or iridocorneal angle.[82]

Other possible complications include elevated intraocular pressure;[78] swelling or oedema of the cornea, which is sometimes associated with transient or permanent cloudy vision (pseudophakic bullous keratopathy); displacement or dislocation of the IOL implant; unplanned high refractive error—either myopic or hypermetropic—due to errors in the ultrasonic biometry (measurement of the eye length and calculation of the required intraocular lens power); cyanopsia, which often occurs for a few days, weeks or months after removal of a cataract; and floaters, which commonly appear after surgery.[40]

It may be necessary to exchange,[Note 11] remove[Note 12] or reposition[Note 13] an IOL after surgery, for any of the following reasons:[78]

  • Capsular block syndrome, which consists in the hyper-distention of the lens capsular bag, due to the IOL blocking fluid from draining through the anterior capsulotomy. This may cause a myopic refractive error;[78]
  • Chronic anterior uveitis, which is a persistent inflammation of the anterior segment;[78]
  • Chronic loss of endothelial cells faster than the rate due to normal aging;[78]
  • Iris pigment epithelium loss;[78]
  • Physical pain;[78]
  • Progressive elongation of the pupil in direction of the IOL's long axis;[78]
  • Progressive closing of the anterior chamber angle, due to propagation of anterior synechiae without apparent anterior uveitis;[78]
  • Incorrect IOL refractive power;[78]
  • Incorrect positioning of the IOL (including decentring, tilt, or rotation), which partially prevents its correct function;[78]
  • Damage or deformation of the IOL;[78]
  • Unexpected optical results due to defects of the IOL;[78]
  • Undesirable optical phenomena reported by the patient due to any other cause.[78]

Risk edit

Statistically, cataract surgery and IOL implantation have the safest and highest success rates of any eye care-related procedures.[7] As with any type of surgery, however, some level of risk remains. As of 2011, cataract surgery is the most frequently performed surgical procedure in the United States, with 1.8 million Medicare beneficiaries undergoing the procedure in 2004. This rate is expected to increase as the population ages.[83]

Most complications of cataract surgery do not result in long-term visual impairment, but some severe complications can lead to irreversible blindness.[83] A survey of adverse results affecting Medicare patients recorded between 2004 and 2006 showed an average rate of 0.5% for one or more severe post-operative complications, with the rate decreasing by about 20% over the study period. The most important risk factors identified were diabetic retinopathy and a combination of cataract surgery with another intraocular procedure on the same day. In the study, 97% of the surgeries were not combined with other intraocular procedures; the remaining 3% were combined with retinal, corneal or glaucoma surgery on the same day.[83]

Recovery and rehabilitation edit

 
A shield or patch may be needed for a few days, mainly to protect from physical impact and contamination

Following cataract surgery, side-effects such as grittiness, watering, blurred vision, double vision, and a red or bloodshot eye may occur, although they usually clear after a few days. Full recovery from the operation can take four-to-six weeks.[84] Patients are usually advised to avoid getting water in the eye during the first week after surgery, and to avoid swimming for two-to-three weeks as a conservative approach, to minimise risk of bacterial infection.[7] Most people can return to normal activities the day after phacoemulsification surgery.[85] Depending on the procedure, they should avoid driving for at least 24 hours after the surgery, largely due to effects from the anaesthesia, possible swelling affecting focus, and pupil dilation causing excessive glare. At the first post-operative check, the surgeon will usually assess whether the patient's vision is suitable for driving.[85]

With small-incision self-sealing wounds used with phacoemulsification, some of the post-operative restrictions common with intracapsular and extracapsular procedures are not relevant. Restrictions against lifting and bending were intended to reduce the risk of the wound opening, because straining increases intraocular pressure. With a self-sealing tunnel incision, however, higher pressure closes the wound more tightly. Routine use of a shield is not usually required, because inadvertent finger pressure on the eye should not open a correctly structured incision, which should only open to point pressure.[7] After surgery, patients need to prevent contamination by avoiding rubbing their eyes, as well as not using eye makeup, face cream or lotions. Any kind of contact with excessive dust, wind, pollen or dirt should also be avoided. Moreover, people are advised to wear sunglasses on bright days, since the eyes become more sensitive to bright light for a prolonged period after surgery.[86]

Topical anti-inflammatory drugs and antibiotics are commonly used in the form of eyedrops to reduce the risk of inflammation and infection. A shield or eye-patch may be prescribed to protect the eye while sleeping. The eye will be checked to ensure the IOL remains in place, and once it has fully stabilized (after about six weeks), vision tests will be used to check whether prescription lenses are needed.[2][84] In cases where the focal length of the IOL is optimised for distance vision, reading glasses are generally needed for near focus.[87]

In some cases, people are dissatisfied with the optical correction provided by the initial implants, making removal and replacement necessary; this can occur with more complex IOL designs, as the patient's expectations might not match with the compromises inherent in these designs, or they might not be able to accommodate the difference in distance and near-focusing of monovision lenses.[33] The patient should not participate in contact or extreme sports, or similar activities, until cleared to do so by the eye surgeon.[88]

Outcomes edit

See also: Visual acuity

After full recovery, visual acuity depends on the underlying condition of the eye, the choice of IOL, and any long-term complications associated with the surgery. More than 90% of operations are successful in restoring useful vision, with a low complication rate.[89] The World Health Organization (WHO) recommends at least 80% of eyes should have a presenting visual acuity of 6/6 to 6/18 (20/20 to 20/60) after surgery, which is considered a good enough visual outcome; the percentage is expected to reach at least 90% with best correction. Acuity of between 6/18 and 6/60 (20/60 to 20/200) is regarded as borderline, whereas a value worse than 6/60 (20/200) is considered poor. Borderline or poor visual outcomes are usually influenced by pre-surgery conditions such as glaucoma, macular disease, and diabetic retinopathy.[90]

Refractive results using power calculation formulae based on pre-operative biometrics leave people within 0.5 dioptres of target (correlates to visual acuity of 6/7.5 (20/25) when targeted for distance) in 55% of cases and within one dioptre (correlates to 6/12 (20/40) when targeted for distance) in 85% of cases. Developments in intra-operative wavefront technology have demonstrated power calculations that provide improved outcomes, yielding 80% of patients within 0.5 dioptres (6/7.5 (20/25) or better).[37]

A ten-year prospective survey on refractive outcomes from a UK National Health Service (NHS) cataract surgery service from 2006 to 2016 showed a mean difference between the targeted and outcome refraction of −0.07 dioptres, with a standard deviation of 0.67, and a mean absolute error of 0.50 dioptres. 88.76% were within one diopter of target refraction and 62.36% within 0.50 dioptres.[91]

According to a 2009 study conducted in Sweden, factors that affected predicted refraction error included sex, pre-operative visual acuity and glaucoma, together with other eye conditions. Second-eye surgery, macular degeneration, age and diabetes did not affect the predicted outcome. Prediction error decreased with time, which is likely due to the use of improved equipment and techniques, including more-accurate biometry.[92] A 2013 American survey involving nearly two million bilateral cataract surgery patients found immediate sequential bilateral cataract surgery was statistically associated with worse visual outcomes than for delayed sequential bilateral cataract surgery; however, the difference was small and might not be clinically relevant.[93]

There is a tendency for post-operative refraction to vary slightly over several years. A small overall myopic shift has been recorded in 33.6% and a small hypermetropic shift in 45.2% of eyes with the remaining 21.2% in the study having no reported change. Most of the change occurred during the first year after surgery.[94]

Phacoemulsification via a coaxial incision[Note 14] may be associated with less astigmatism than the average for bimanual incisions,[Note 15] but the difference was found to be small and the evidence statistically uncertain.[95][96]

History edit

 
A cataract surgery. Dictionnaire Universel de Médecine (1746–1748)
Main article: History of cataract surgery

Cataract surgery has a long history in Europe, Asia, and Africa. It is one of the most common and successful surgical procedures in worldwide use, due to improvements in techniques for cataract removal, and developments in intraocular lens replacement technology, in implantation techniques, and in IOL design, construction, and selection.[97] Surgical techniques that have contributed to this success include microsurgery, viscoelastics, phacoemulsification and self sealing incisions.[98]

Couching was the original form of cataract surgery, and was used from antiquity. It is still occasionally found in traditional medicine in parts of Africa and Asia. In 1753, Samuel Sharp performed the first-recorded surgical removal of the entire lens and lens capsule, equivalent to intracapsular cataract extraction. The lens was removed from the eye through a limbal incision.[97]

In 1884, Karl Koller became the first surgeon to apply a cocaine solution to the cornea as a local anaesthetic in 1884.[99][100] By the beginning of the 20th century, the standard surgical procedure was intracapsular cataract extraction (ICCE).[7]

In 1949, Harold Ridley introduced the concept of implantation of the intraocular lens (IOL) which made visual rehabilitation after cataract surgery a more efficient, effective, and comfortable process.[97]

Intracapsular cryoextraction was the favoured form of cataract extraction from the late 1960s to the early 1980s using a liquid-nitrogen-cooled probe tip to freeze the encapsulated lens to the probe.[17][15][101]

In 1967, Charles Kelman introduced phacoemulsification, which uses ultrasonic energy to emulsify the nucleus of the crystalline lens and remove cataracts by aspiration without a large incision. This method of surgery reduced the need for an extended hospital stay and made out-patient surgery the standard.[102]

Ophthalmic viscosurgical devices (OVDs), which were introduced in 1972, facilitate the procedure and improve overall safety, particularly of phacoemulsification, by maintaining the shape of the eye at reduced pressure, and protecting the internal tissues of the eye without interfering with the operation.[97]

In the early 1980s, Danièle Aron-Rosa and colleagues introduced the neodymium-doped yttrium aluminum garnet laser (Nd:YAG laser) for posterior capsulotomy.[7] In 1985, Thomas Mazzocco developed and implanted the first foldable IOL, and Graham Barrett and associates pioneered the use of silicone, acrylic, and hydrogel foldable lenses.[7]

In 1987, M. Blumenthal and J. Moisseiev described the use of a reduced incision size for ECCE. They used a 6.5 to 7 mm (0.26 to 0.28 in) straight scleral tunnel incision 2 mm (0.079 in) behind the limbus with two side ports, and an anterior chamber maintainer.[59] In 1989, M. McFarland introduced a self-sealing incision architecture, and in 1990, S.L.Pallin described a chevron-shaped incision that minimized the risk of induced astigmatism.[59] In 2009, Praputsorn Kosakarn described a method for manual fragmentation of the lens, called "double-nylon loop", which consists in splitting the lens into three pieces for extraction, allowing a smaller, sutureless incision of 4.0 to 5.0 mm (0.16 to 0.20 in), and requires implantation of a foldable IOL. This technique uses less expensive instruments than phacoemeulsification, and is suitable for use in developing countries.[59]

Regional practice and statistics edit

United Kingdom edit

In the UK, the practice of NHS healthcare providers referring people with cataracts to surgery widely varied as of 2017; many of the providers were only referring patients with moderate or severe vision loss, often with delays.[103] This practise occurred despite guidance issued by the NHS Executive in 2000, which urged providers to standardize care, streamline the process and increase the number of cataract surgeries performed, in order to meet the needs of the aging population.[104] In 2019, the national ophthalmology outcomes audit found five NHS trusts had complication rates of between 1.5% and 2.1%: however, since the first national cataract audit (held in 2010), there had been a 38% reduction in posterior capsule rupture complications.[105]

Asia edit

South Asia has the highest global age-standardized prevalence of moderate-to-severe visual impairment (17.5%) and mild visual impairment (12.2%). The estimated distribution of ophthalmologists ranges from more than 114 per million of population in Japan, to none in Micronesia. Cataract has traditionally been a major cause of blindness in less-developed countries in the region, and in spite of improvements to the volume and quality of cataract surgeries, the success rate (CSR) remains low for some of these nations.[106]

China edit

Cataracts are common in China; as of 2022, their estimated overall prevalence in Chinese people over 50 years old was 27.45%. The environment was an influential factor, with the prevalence being 28.79% in rural areas, and 26.66% in urban areas. Prevalence of cataract considerably varies by age group, as well: for ages 50-59, it is 7.88%; for ages 60-69, it is 24.94%; for ages 70-79, it is 51.74%; in people over 80 years old, it is 78.43%. The overall cataract-surgery coverage rate was 9.19%. The prevalence of cataract and cataract surgical coverage also significantly varies by region.[107]

India edit

Main article: Eye care in India

India's cataract-surgical rate rose from just over 700 operations per million people per year in 1981, to 6,000 per million per year in 2011, thus getting increasingly closer to the estimated requirement of 8,000-8,700 operations per million per year needed to eliminate cataract blindness in the country. The rate's rise was partly linked to factors such as increased efficiency due to improved surgical techniques, application of day-case surgery, improvements in operating theatre design, and efficient teamwork with sufficient staff.[108]

In India, the pool of people applying for cataract surgery has been widened through social marketing methods aimed to raise awareness about the condition and access to effective surgical treatments. The non-governmental organization (NGO) sector and Indian ophthalmologists have developed methods to deal with several problems affecting local communities, including outreach camps to find those needing surgery, counsellors to explain the system, locally manufactured equipment and consumables, and a tiered pricing structure using subsidies where appropriate.[108]

There have been occasional incidents in which several patients have been infected and developed endophthalmitis on the same day at some hospitals associated with eye camps in India. Journalists have reported blame being placed on the surgeons, the hospital administration, and other persons, but have not reported on those responsible for sterilizing the surgical instruments and operating theatres involved, whether all infections involved the same micro-organisms, the same theatres, or the same staff. One investigation found bacteria known to be associated with endophthalmia in the theatre and in the eyes of affected patients, and it was claimed the hospital had not followed the required protocol for infection control, but the investigation was ongoing and no findings were reported. Several instances of surgeons performing more operations per day than officially allowed have been reported, but the effects upon sterility of equipment or plausible infection pathways have not been explained.[109]

In 2022, digital news portal Scroll.in contacted the Ministry of Health and Family Welfare, requesting official data on the number of patients who had contracted infections following surgery; according to their researches, since 2006, 469 people had either been blinded in one eye or had their vision seriously affected after undergoing surgery at eye camps. Further inquiries found at least 519 patients were involved, but the total number of surgeries for that period was not mentioned.[109] As of 2017, India is claimed to be performing about 6.5 million cataract surgeries per year, more than the US, Europe and China together.[110]

Africa edit

 
Cataract surgery in Bedele, Ethiopia

Cataracts are the main cause of blindness in Africa, and affect approximately half of the estimated seven million blind people on the continent, a number that is expected to increase with population growth by about 600,000 people per year. As of 2005, the estimated cataract-surgery rate was about 500 operations per million people per year. Progress on gathering information on epidemiology, distribution and impact of cataracts within the African continent has been made, but significant problems and barriers limiting further access to reliable data remain.[111]

These barriers relate to awareness, acceptance, and cost; some studies also reported community and family dynamics as discouraging factors. Most of the studies held locally reported that cataract-surgical rate was lower in females. The higher cataract-surgery coverage found in some settings in South Africa, Libya, and Kenya suggest many barriers to surgery can be overcome.[112]

According to the International Agency for the Prevention of Blindness, some sub-Saharan African countries have about one ophthalmologist per million people, while the National Center for Biotechnology Information stated the percentage of adults above the age of 50 in western sub-Saharan Africa who have developed cataract-induced blindness is about 6%—the highest rate in the world.[113]

A mathematical model using survey data from sub-Saharan Africa showed the incidence of cataracts varies significantly across the continent, with the required rate of surgery to maintain a visual acuity level of 6/18 (20/60) ranging from about 1,200 to about 4,500 surgeries per year per million people, depending on the area. Such variations may relate to genetic or cultural differences, as well as life expectancy.[114]

Nigeria edit

In 2011, 0.78% of the population of Nigeria were blind; more than 43% of these developed the condition from cataracts, whereas another 9% was a result of aphakia and complications from couching performed by itinerant practitioners. Although there are about 2.8 ophthalmologists per million population in Nigeria, the cataract-surgery rate is only 300 operations per million per year (compared with the WHO recommendation of 3,000 per million per year). Reasons cited for this situation include inadequate blindness prevention programs, shortage of funding and lack of government-led investments in training and services. Teaching hospitals do not have enough patient-surgical load to support training.[115]

South Africa edit

In South Africa, facilities vary from government hospitals, where subsidised operations for the disadvantaged may be charged at rates that cover the consumables, to private clinics in which up-to-date equipment is used and patients are charged at premium rates. Waiting times in government hospitals may be up to two years, whereas they are much shorter at private clinics. Some hospitals use a system in which two patients are operated upon for cataracts in the theatre at the same time, increasing the efficiency of facilities.[116] Some charitable organisations in the country provide pro bono cataract surgery in rural areas by using mobile clinics.[117][118]

As of 2023, the cataract-surgery rate in South Africa is less than half of the estimated requirement of at least 2,000 per million population per year needed to eliminate cataract blindness.[119][120] In 2011, Lecuona and Cook identified an inadequate level of human resources in the public sector to provide care for the indigent population.[120] The main barrier to increasing South Africa's rate of cataract surgery is inadequate surgery capacity: a higher annual rate of cataract surgeries by individual surgeons would improve cost effectiveness and personal skills, and also contribute towards an overall reduction of risk.[120]

Latin America edit

 
Cataract operation in São Paulo, Brazil

A four-year longitudinal study of 19 Latin American countries published in 2010 showed most of the countries had increased their surgery rates over that period, with increases of up to 186%, but still failed to provide adequate surgical coverage. The study also shown a significant correlation between gross national income per capita and cataract-surgery rate in the countries involved.[121]

In a study published in 2014, the weighted-mean regional surgery rate was found to have increased by 70% from 2005 to 2012, rising from 1,562 to 2,672 cataract surgeries per million inhabitants. The weighted mean number of ophthalmologists per million inhabitants in the region was approximately 62. Cataract-surgery coverage widely varied across Latin America, ranging from 15% in El Salvador, to 77% in Uruguay. Barriers cited included cost of surgery and lack of awareness about available surgical treatment. The number of available ophthalmologists appeared to be adequate, but the number of those who practised eye surgery was unknown.[122]

A 2009 study showed that the prevalence of cataract blindness in people 50 years and older ranged from 0.5% in Buenos Aires, to 2.3% in parts of Guatemala. Poor vision due to cataracts ranged from 0.9% in Buenos Aires, to 10.7% in parts of Peru. Cataract-surgical coverage ranged from good in parts of Brazil to poor in Paraguay, Peru, and Guatemala. Visual outcome after cataract surgery was close to conformity with WHO guidelines in Buenos Aires, where more than 80% of post-surgery eyes had visual acuity of 6/18 (20/60) or better, but ranged between 60% and 79% in most of the other regions, and was less than 60% in Guatemala and Peru.[123]

Social and economic relevance edit

The cost of cataract surgery depends on the type of procedure, whether it is provided privately or by a government hospital, whether it is provided by out-patient (day care) or in-patient surgery, and on the economic status of people in the region. Because of the high cost of the equipment, phacoemulsification is generally more expensive than ECCE and MSICS.[6] Visual outcomes are variable; they depend upon the underlying condition of the eyes, and the surgical techniques and lens implants used. Regional variations exist due to quality and availability of care.

The restoration of functional vision or improvement in vision possible in most cases has a large social and economic impact; patients may be able to return to paid work or continue their previous jobs, and may not become dependent on support from their family or the wider society. Studies show a sustained improvement to quality of life, financial situation, physical well-being, and mental health. Cataract surgery is one of the most cost-effective health interventions, since its economic benefits considerably exceed the cost of treatment.[124][125]

The 1998 World Health Report estimated 19.34 million people were bilaterally blind due to age-related cataracts, and that cataracts were responsible for 43% of all cases of blindness. This number and proportion were expected to increase due to population growth, and increased life expectancy approximately doubling the number of people older than 60 years. The global increase in blindness from cataract is estimated to be at least five million per year; a figure of 1,000 new cases per million population per year is used for planning purposes. The average outcomes of cataract surgery are improving, and consequently, surgery is being indicated at an earlier stage in cataract progression, increasing the number of operable cases. To reduce the backlog of patients, it is necessary to operate on more people per year than the new cases alone.[126]

As of 1998, the rate of surgeries in economically developed countries was about 4,000 to 6,000 per million population per year, which was sufficient to meet demand. India raised the cataract surgery rate (CSR) to over 3,000, but this was not considered to be sufficient to reduce the backlog. Middle-income countries of Latin America and Asia have CSRs of between 500 and 2,000 per million per year, whereas China, most of Africa, and poor countries of Asia had rates of less than 500. In India and South East Asia, the rate required to keep up with the increase is at least 3,000 per million population per year; in Africa and other parts of the world with smaller percentages of older people, a rate of 2,000 may be sufficient in the short term.[126]

Vision 2020: The Right to Sight, a global initiative of the International Agency for the Prevention of Blindness (IAPB), was intended to reduce or eliminate the main causes of avoidable blindness worldwide by 2020. Programs instituted under Vision 2020 facilitated the planning, development, and implementation of sustainable national eye-care programs, including technical support and advocacy.[127] The IAPB and WHO launched the program on 18 February 1999.[128][129]

The Vision 2020 initiative succeeded in bringing avoidable blindness to the global health agenda. The causes have not been eliminated, but there have been significant changes to their distribution, which have been attributed to global demographic shifts. Remaining challenges to management of avoidable blindness include population size, gender disparities in access to eye-care, and the availability of a professional workforce.[129]

It has been estimated there were 43.3 million blind people in 2020, and 295 million with moderate and severe visual impairment (MSVI), 55% of whom were female. The age-standardised global prevalence in blindness decreased by 28.5% between 1990 and 2020, but the age-standardised prevalence of MSVI increased by 2.5%. Cataract remained the global leading cause of blindness in 2020.[129]

Special populations edit

Congenital cataracts edit

Main article: Congenital cataract
 
Bilateral cataracts in an infant due to congenital rubella syndrome

Congenital cataracts involve a condition of lens opacity that is present at birth, and occur in a broad range of severity; some lens opacities do not progress and are visually insignificant, while others can produce profound visual impairment. Congenital cataracts may be unilateral or bilateral. They can be classified by morphology, presumed or defined genetic cause, presence of specific metabolic disorders, or associated ocular anomalies or systemic findings.[3]

In general, there is greater urgency to remove dense cataracts from very young children because of the risk of amblyopia. For optimal visual development in newborns and young infants, a visually significant unilateral congenital cataract should be detected and removed before the child is six weeks old, while visually significant bilateral congenital cataracts should be removed before 10 weeks.[3] Congenital cataracts that are too small to affect vision will not be removed or treated, but may be monitored by an ophthalmologist throughout the patient's life. Commonly, a patient with small congenital cataracts that do not damage vision will be affected later in life, though this will take decades to occur.[130]

As of 2015, the standard of care for pediatric cataract surgery for children older than two years is primary posterior intraocular lens (IOL) implantation. Primary IOL implantation before the age of seven months is considered to have no advantages over aphakia.[131] According to a 2015 study, primary IOL implantation in the seven-months-to-two-years age groups should be considered in children who require cataract surgery.[131] Research into the possibility of regeneration of infant lenses from lens epithelial cells showed interesting results in a small trial study reported in 2016.[132][133]

Developing world edit

The capital equipment for phacoemulsification is expensive and requires expert maintenance, and the consumables are also expensive. Quality of outcomes is not sufficiently better than those for manual small incision cataract surgery (MSICS) to justify the difference in cost in a developing world environment.[6]

Higher risk for operations on separate occasions edit

Most patients have bilateral cataracts; although surgery in one eye can restore functional vision, second-eye surgery has many advantages, so most patients undergo surgery in each eye on separate days. Operating on both eyes on the same day as separate procedures is known as immediately sequential bilateral cataract surgery; this can decrease the number of hospital visits, thus reducing risk of contagion in an epidemic. Immediately sequential bilateral cataract surgery also has significant cost savings, and faster visual rehabilitation and neuroadaptation.[Note 16] Another indication is significant cataracts in both eyes of patients for whom two rounds of anaesthesia and surgery would be unsuitable. The risk of simultaneous bilateral complications is low.[134][135]

Other animals edit

Cataract surgery in small animals such as dogs and cats is a routine ophthalmic procedure with a success rate of around 90%, and is usually better for eyes with relatively recent cataract development. The presence of other ocular problems may reduce the success rate. Procedures are similar to those for humans. General anesthesia is likely to be used,[136] but sub-Tenons and a low-dose neuromuscular blockade protocol have also been used used for canine cataract surgery.[137]

See also edit

Notes edit

  1. ^ Ciliary sulcus: The space between the anterior surface of the ciliary body and the posterior surface of the base of the iris, just in front of the position of the natural lens.
  2. ^ Posterior capsule rupture: Unintended tearing of the posterior membrane of the lens capsule, which can allow migration of the vitreous into the anterior chamber.
  3. ^ White -to-white (WTW) measurement of an eye is the horizontal diameter of the cornea, measured across the corneal limbus.
  4. ^ Intraoperative aberrometry: A tool to take aphakic and pseudophakic refractive measurements during surgery to help optimise IOL power selection and placement.
  5. ^ Bridle suture: A suture passing through the superior rectus muscle of the eye, used to rotate the eyeball downwards in eye surgery.
  6. ^ Hydroexpression: Method of removing the lens from the capsule and anterior chamber by carrying it out in a flow of saline solution.
  7. ^ Viscoexpression: Method of removing the lens from the capsule and anterior chamber by carrying it out in a flow of viscoelastic material.
  8. ^ Zonular dehiscence: Breaking of the fibrous strands (zonules) connecting the crystalline lens to the ciliary body.
  9. ^ Dropped nucleus: A cataract nucleus which has fallen through into the vitreous chamber.
  10. ^ Nanophthalmic: Exceptionally small eyes.
  11. ^ Exchange: The IOL is replaced with another of the same model.
  12. ^ Remove: The IOL is removed and replaced with a different model lens or no replacement lens is implanted.
  13. ^ Reposition: The IOL is surgically moved to another location or rotated.
  14. ^ Coaxial phacoemulsification uses a single probe to irrrigate, emulsify and aspirate, which is operated through a single incision.
  15. ^ Bimanual phacoemulsification uses one probe to emulsify and aspirate, and a second that is only used for irrigation.
  16. ^ Neuroadaptation: Changes in the brain which accommodate the presence of a new substance or condition, such as the admission of more blue light after removal of a yellow tinted cataract, or the inability to adjust the focus of an IOL by the ciliary muscles.

References edit

  1. ^ "Cataracts". www.nei.nih.gov. National Eye Institute. from the original on 2 May 2019. Retrieved 27 July 2020.
  2. ^ a b c d e f g h i j k l m n o p q r s t u v Moshirfar, Majid; Milner, Dallin; Patel, Bhupendra C. (June 21, 2022). "Cataract Surgery". www.ncbi.nlm.nih.gov. National Center for Biotechnology Information. PMID 32644679. from the original on 24 February 2023. Retrieved 8 February 2023.
  3. ^ a b c Basic and clinical science course (2011–2012). Pediatric ophthalmology and Strabismus. American Academy of Ophthalmology. ISBN 978-1615251131.
  4. ^ a b c d e f g h i "Facts About Cataract". September 2009. from the original on 24 May 2015. Retrieved 24 May 2015.
  5. ^ "Cataract surgery". Mayo Foundation for Medical Education and Research (MFMER). from the original on 19 July 2021. Retrieved 19 July 2021.
  6. ^ a b c d e Haldipurkar, S.S.; Shikari, Hasanain T.; Gokhale, Vishwanath (2009). "Wound construction in manual small incision cataract surgery". Indian Journal of Ophthalmology. 57 (1): 9–13. doi:10.4103/0301-4738.44491. ISSN 0301-4738. PMC 2661512. PMID 19075401.
  7. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Cionni, Robert J.; Snyder, Michael E.; Osher, Robert H. (2006). "6: Cataract surgery". In Tasman, William (ed.). Duane's Ophthalmology. Vol. 6. Lippincott Williams & Wilkins. from the original on 20 February 2023. Retrieved 16 February 2023 – via www.oculist.net.
  8. ^ a b c d e f Gurnani, B.; Kaur, K. (6 December 2022). "Manual Small Incision Cataract Surgery". StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing. PMID 35881728. from the original on 1 February 2023. Retrieved 2 March 2023.
  9. ^ a b Moshirfar, M.; Milner, D; Patel, B.C. (January 2023). Cataract Surgery. Treasure Island, FL: StatPearls Publishing. PMID 32644679. from the original on 2023-02-24. Retrieved 2023-02-08.
  10. ^ Pandey, S.K. (2005). Pediatric cataract surgery techniques, complications, and management. Philadelphia: Lippincott Williams & Wilkins. p. 20. ISBN 978-0781743075. from the original on 2015-05-24.
  11. ^ a b . Archived from the original on 24 May 2015. Retrieved 24 May 2015.
  12. ^ Lamoureux, E.L.; Fenwick, E.; Pesudovs, K.; Tan, D. (January 2011). "The impact of cataract surgery on quality of life". Current Opinion in Ophthalmology. 22 (1): 19–27. doi:10.1097/icu.0b013e3283414284. PMID 21088580. S2CID 22760161.
  13. ^ Rao, G.N.; Khanna, R.; Payal, A. (January 2011). "The global burden of cataract". Current Opinion in Ophthalmology. 22 (1): 4–9. doi:10.1097/icu.0b013e3283414fc8. PMID 21107260. S2CID 205670997.
  14. ^ a b c d e f g h Agarwal, Ashvin (March 2019). "When and How to Convert to ECCE: Extracapsular cataract extraction remains a useful plan B." crstoday.com. from the original on 2 March 2023. Retrieved 2 March 2023.
  15. ^ a b Toczolowski, J. (July 1993). "Thirty years of cryoophthalmology". Ann. Ophthalmol. 25 (7): 254–6. PMID 8363292.
  16. ^ Kim, Y.J.; Ha, S.J. (2013). "Intracapsular Lens Extraction for the Treatment of Pupillary Block Glaucoma Associated with Anterior Subluxation of the Crystalline Lens". Case Rep Ophthalmol. 4 (3): 257–264. doi:10.1159/000356530. PMC 3861857. PMID 24348413.
  17. ^ a b Haripriya, A.; Sonawane, H.; Thulasiraj, R.D. (2017). "Changing techniques in cataract surgery: how have patients benefited?". Community Eye Health. 30 (100): 80–81. PMC 5820631. PMID 29483751.
  18. ^ Boughton, Barbara (April 2009). "Phaco and ECCE". EyeNet Magazine. American Academy of Ophthalmology. Retrieved 5 December 2023.
  19. ^ Lawrence, D.; Fedorowicz, Z.; van Zuuren, E.J.; et al. (Cochrane Eyes and Vision Group) (November 2015). "Day care versus in-patient surgery for age-related cataract". The Cochrane Database of Systematic Reviews. 2015 (11): CD004242. doi:10.1002/14651858.CD004242.pub5. PMC 7197209. PMID 26524611.
  20. ^ Liaska, A; Papaconstantinou, D; Georgalis, I; Koutsandrea, C; Theodosiadis, P; Chatzistefanou, K. (July 2014). "Phaco-trabeculectomy in controlled, advanced, open-angle glaucoma and cataract: Parallel, randomized clinical study of efficacy and safety". Semin Ophthalmol. 29 (4): 226–35. doi:10.3109/08820538.2014.880491. PMID 24654699. S2CID 19497442.
  21. ^ Akman, A; Yilmaz, G; Oto, S; Akova, YA (September 2004). "Comparison of various pupil dilatation methods for phacoemulsification in eyes with a small pupil secondary to pseudoexfoliation". Ophthalmology. 111 (9): 1693–8. doi:10.1016/j.ophtha.2004.02.008. PMID 15350324.
  22. ^ Rishi, P.; Sharma, T.; Rishi, E.; Chaudhary, S.P. (January–April 2009). "Combined scleral buckling and phacoemulsification". Oman J Ophthalmol. 2 (1): 15–8. doi:10.4103/0974-620X.48416. PMC 3018099. PMID 21234218.
  23. ^ Charters, Linda (15 June 2006). . Ophthalmology Times. Archived from the original on 22 October 2006. Retrieved 2 April 2007.
  24. ^ Keay, L.; Lindsley, K.; Tielsch, J.; Katz, J.; Schein, O. (January 2019). "Routine preoperative medical testing for cataract surgery". The Cochrane Database of Systematic Reviews. 1 (1): CD007293. doi:10.1002/14651858.CD007293.pub4. PMC 6353242. PMID 30616299.
  25. ^ Yorston, D. (2001). "Intraocular Lens (IOL) Implants in Children". Community Eye Health. 14 (40): 57–8. PMC 1705947. PMID 17491933.
  26. ^ Lambert, S.R.; Aakalu, V.K.; Hutchinson, A.K.; Pineles, S.L.; Galvin, J.A.; Heidary, G.; Binenbaum, G.; VanderVeen, D.K. (October 2019). "Intraocular Lens Implantation during Early Childhood: A Report by the American Academy of Ophthalmology". Ophthalmology. 126 (10): 1454–1461. doi:10.1016/j.ophtha.2019.05.009. PMID 31230794. S2CID 195327519. from the original on 2023-02-27. Retrieved 2023-02-27.
  27. ^ a b c d e "Who is NOT a Candidate for Cataract Surgery?". www.pacificvision.org. Retrieved 5 December 2023.
  28. ^ a b c d Gogate, P.; Wood, M. (March 2008). "Recognising 'high-risk' eyes before cataract surgery". Community Eye Health. 21 (65): 12–14. PMC 2377383. PMID 18504470.
  29. ^ a b c Sridhar, U; Tripathy, K. (22 August 2022). "Monofocal Intraocular Lenses". StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing. PMID 35593809. from the original on 10 July 2022. Retrieved 8 February 2023.
  30. ^ a b Mehta, R.; Aref, A.A. (November 2019). "Intraocular Lens Implantation In The Ciliary Sulcus: Challenges And Risks". Clin. Ophthalmol. 27 (13): 2317–2323. doi:10.2147/OPTH.S205148. PMC 6885568. PMID 31819356.
  31. ^ a b Goldsberry, Dennis H. (May 2012). "Achieving Better Outcomes Using Free Online Post-LASIK IOL Calculators". crstodayeurope.com. CRSTEurope. from the original on 11 February 2023. Retrieved 11 February 2023.
  32. ^ Singh, Vivek Mahendrapratap; Ramappa, Muralidhar; Murthy, Somasheila; Rostov, Audrey Talley (January 2022). "Toric intraocular lenses: Expanding indications and preoperative and surgical considerations to improve outcomes". Indian J Ophthalmol. 70 (1): 10–23. doi:10.4103/ijo.IJO_1785_21. PMC 8917572. PMID 34937203.
  33. ^ a b Grayson, Douglas (4 October 2011). "The Ins and Outs of Lens Explantation". Review of Ophthalmology. from the original on 14 February 2023. Retrieved 14 February 2023.
  34. ^ Salerno, Liberdade C.; Tiveron, Jr., Mauro C.; Alió, Jorge L. (2017). "Multifocal intraocular lenses: Types, outcomes, complications and how to solve them". Taiwan Journal of Ophthalmology. 7 (4): 179–184. doi:10.4103/tjo.tjo_19_17. PMC 5747227. PMID 29296549.
  35. ^ MacRae, Scott. "Crystalens: The First Accommodating Intraocular Lens Implant". www.urmc.rochester.edu. University of Rochester Flaum Eye Institute. from the original on 14 February 2023. Retrieved 14 February 2023.
  36. ^ Ramappa, Muralidhar; Singh, Vivek Mahendrapratap; Murthy, SomasheilaI; Rostov, AudreyTalley (2022). "Toric intraocular lenses: Expanding indications and preoperative and surgical considerations to improve outcomes". Indian Journal of Ophthalmology. 70 (1): 10–23. doi:10.4103/ijo.IJO_1785_21. ISSN 0301-4738. PMC 8917572. PMID 34937203.
  37. ^ a b Roach, Linda (September 2013). "Intraoperative Wavefront Aberrometry: Wave of the Future?". EyeNet Magazine. American Academy of Ophthalmology. from the original on 26 February 2023. Retrieved 26 February 2023.
  38. ^ Roach, Linda (November–December 2010). "How to Choose an Aspheric Intraocular Lens". EyeNet Magazine. American Academy of Ophthalmology. from the original on 17 February 2023. Retrieved 17 February 2023.
  39. ^ Downie, L.E.; Busija, L.; Keller, P.R.; et al. (Cochrane Eyes and Vision Group) (May 2018). "Blue-light filtering intraocular lenses (IOLs) for protecting macular health". The Cochrane Database of Systematic Reviews. 2018 (5): CD011977. doi:10.1002/14651858.CD011977.pub2. PMC 6494477. PMID 29786830.
  40. ^ a b Hayashi, K.; Hayashi, H. (2006). "Visual function in patients with yellow tinted intraocular lenses compared with vision in patients with non-tinted intraocular lenses". British Journal of Ophthalmology. 90 (8): 1019–1023. doi:10.1136/bjo.2006.090712. PMC 1857188. PMID 16597662.
  41. ^ "FDA Approves RxSight's Light Adjustable Lens, First IOL To Enable Refractive Correction After Cataract Surgery". innovation.ucsf.edu. University of California San Francisco. 27 November 2017. from the original on 21 February 2023. Retrieved 21 February 2023.
  42. ^ Jain, Sneha; Patel, Alpa S.; Tripathy, Koushik; DelMonte, Derek W.; Baartman, Brandon (3 October 2022). DelMonte, Derek W. (ed.). "Light Adjustable Intraocular lenses". EyeWiki. American Academy of Ophthalmology. from the original on 16 February 2023. Retrieved 16 February 2023.
  43. ^ Portelinha, Joana; Ferreira, Tiago Luís do Carmo Bravo; Reddy, Vandana; Shafer, Brian (8 January 2023). Shafer, Brian (ed.). "Special Cases: Secondary Piggy-Back Lenses". Eyewiki. American Academy of Ophthalmology. from the original on 20 February 2023. Retrieved 20 February 2023.
  44. ^ Hasan, Sumaiya; Tripathy, K. (22 August 2022). "Phakic Intraocular Lens Myopia". StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing. PMID 32809598. from the original on 20 December 2022. Retrieved 21 February 2023.
  45. ^ Vicchrilli, Sue; Glasser, David B.; McNett, Cherie; Burke, Mara Pearse; Repka, Michael X. (October 2018). "Premium IOLs—A Legal and Ethical Guide to Billing Medicare Beneficiaries". EyeNet Magazine. from the original on 21 February 2023. Retrieved 21 February 2023.
  46. ^ a b c d Minakaran, N.; Ezra, D.G.; Allan, B.D. (July 2020). "Topical anaesthesia plus intracameral lidocaine versus topical anaesthesia alone for phacoemulsification cataract surgery in adults". The Cochrane Database of Systematic Reviews. 2020 (7): CD005276. doi:10.1002/14651858.cd005276.pub4. PMC 8190979. PMID 35658539.
  47. ^ a b c Gurnani, Bharat; Kaur, Kirandeep (6 December 2022). "Phacoemulsification". StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing. PMID 35015444. from the original on 30 January 2023. Retrieved 20 February 2023.
  48. ^ Wier, L.M.; Steiner, C.A.; Owens, P.L. (February 2015). "Surgeries in Hospital-Owned Outpatient Facilities, 2012". HCUP Statistical Brief #188. Rockville, MD: Agency for Healthcare Research and Quality. from the original on 2021-05-14. Retrieved 2015-04-06.
  49. ^ "Cataract surgery". Mayo Foundation for Medical Education and Research (MFMER). from the original on 19 July 2021. Retrieved 19 July 2021.
  50. ^ Alió, J.L.; Abdou, A.A.; Puente, A.A.; Zato, M.A.; Nagy, Z. (June 2014). "Femtosecond laser cataract surgery: updates on technologies and outcomes". Journal of Refractive Surgery. 30 (6): 420–427. doi:10.3928/1081597x-20140516-01. PMID 24972409.
  51. ^ Popovic, M.; Campos-Möller, X; Schlenker, M.B.; Ahmed, I.I. (October 2016). "Efficacy and Safety of Femtosecond Laser-Assisted Cataract Surgery Compared with Manual Cataract Surgery: A Meta-Analysis of 14 567 Eyes". Ophthalmology. 123 (10): 2113–2126. doi:10.1016/j.ophtha.2016.07.005. PMID 27538796.
  52. ^ Devgan, Uday (15 August 2017). "Three rules for corneal phaco incisions". www.healio.com. Retrieved 12 December 2023.
  53. ^ a b Scholtz, Sibylle (January 2007). "History of Ophthalmic Viscosurgical Devices". crstodayeurope.com. Cataract & Refractive Surgery Today Europe. from the original on 13 February 2023. Retrieved 13 February 2023.
  54. ^ Mohammadpour, M.; Erfanian, R.; Karimi, N. (January 2012). "Capsulorhexis: Pearls and pitfalls". Saudi J Ophthalmol. 26 (1): 33–40. doi:10.1016/j.sjopt.2011.10.007. PMC 3729482. PMID 23960966.
  55. ^ Yanoff, Myron; Duker, Jay S. (1 January 2009). Ophthalmology. Elsevier Health Sciences. ISBN 978-0323043328. from the original on 19 February 2023. Retrieved 19 February 2023 – via Google Books.
  56. ^ Faust, KJ. (Winter 1984). "Hydrodissection of soft nuclei". J Am Intraocul Implant Soc. 10 (1): 75–7. doi:10.1016/s0146-2776(84)80088-9. PMID 6706823.
  57. ^ Patel, Alpa S.; DelMonte, Derek W.; Mohan, Hridya; Christenbury, Joseph (24 September 2022). Christenbury, Joseph (ed.). "Hydro Manoeuvres in Cataract Surgery". Eyewiki. American Academy of Ophthalmology. from the original on 20 February 2023. Retrieved 20 February 2023.
  58. ^ Mathey, Christoph F.; Kohnen, Thomas B.; Ensikat, Hans-Jürgen; Koch, Hans-Reinhard (January 1994). "Polishing methods for the lens capsule: Histology and scanning electron microscopy". Journal of Cataract & Refractive Surgery. 20 (1): 64–69. doi:10.1016/S0886-3350(13)80046-6. PMID 8133483. S2CID 11738948.
  59. ^ a b c d e f Singh, K.; Misbah, A.; Saluja, P.; Singh, A.K. (December 2017). "Review of manual small-incision cataract surgery". Indian J Ophthalmol. 65 (12): 1281–1288. doi:10.4103/ijo.IJO_863_17. PMC 5742955. PMID 29208807.
  60. ^ Devgan, Uday (27 January 2019). "Use of an AC maintainer in Cataract Surgery". cataractcoach.com. from the original on 1 March 2023. Retrieved 1 March 2023.
  61. ^ Oetting, Thomas. . Archived from the original on 26 August 2008. Retrieved 28 May 2008.
  62. ^ Thim, K.; Krag, S.; Corydon, L. (March 1993). "Hydroexpression and viscoexpression of the nucleus through a continuous circular capsulorhexis". J Cataract Refract Surg. 19 (2): 209–12. doi:10.1016/s0886-3350(13)80944-3. PMID 8487162. S2CID 35741983. from the original on 2023-03-01. Retrieved 2023-03-01.
  63. ^ Varshney, S.; Jhala, L.S. (November 2022). "Hydroexpression - A novel technique to deliver nucleus in small-incision cataract surgery". Indian J Ophthalmol. 70 (11): 4066. doi:10.4103/ijo.IJO_1594_22. PMC 907245. PMID 36308162.
  64. ^ Mohan, S.; John, B.; Rajan, M.; Malkani, H.; Nagalekshmi, S.V.; Singh, S. (June 2017). "Glued intraocular lens implantation for eyes with inadequate capsular support: Analysis of the postoperative visual outcome". Indian J Ophthalmol. 65 (6): 472–476. doi:10.4103/ijo.IJO_375_16. PMC 5508457. PMID 28643711.
  65. ^ a b Wang, Robert C.; Fuller, Dwain G.; Hutton, William S. (2006). "66: Retained Lens Material". In Tasman, William (ed.). Duane's Ophthalmology. Vol. 6. Lippincott Williams & Wilkins. from the original on 19 February 2023. Retrieved 16 February 2023 – via www.oculist.net.
  66. ^ Vajpayee, R.B.; Sharma, N.; Dada, T.; Gupta, V.; Kumar, A.; Dada, V.K. (1 June 2001). "Management of posterior capsule tears". Surv Ophthalmol. 45 (6): 473–88. doi:10.1016/s0039-6257(01)00195-3. PMID 11425354.
  67. ^ Chaturvedi, Vivek; Sabherwal, Ryan; Kim, Leo A.; Pittner, Andrew; Bhagat, Neelakshi; Lim, Jennifer I; Mukkamala, Lekha; Patel, Nimesh (23 June 2022). Patel, Nimesh (ed.). "Suprachoroidal Hemorrhage". Eyewiki. American Academy of Ophthalmology. from the original on 13 December 2022. Retrieved 22 February 2023.
  68. ^ Hilford, D.; Hilford, M.; Mathew, A.; Polkinghorne, P.J. (2009). "Posterior vitreous detachment following cataract surgery". Eye. 23 (6): 1388–1392. doi:10.1038/eye.2008.273. PMID 18776863.
  69. ^ "Videos: YAG Laser Capsulotomy". Pacific Cataract and Laser Institute. from the original on 2 April 2019. Retrieved 2 April 2019.
  70. ^ Karahan, Eyyup; Er, Duygu; Kaynak, Suleyman (Summer 2014). "An Overview of Nd:YAG Laser Capsulotomy". Medical Hypothesis, Discovery & Innovation in Ophthalmology Journal. 3 (2): 45–50. PMC 4346677. PMID 25738159.
  71. ^ a b Steel, D. (March 2014). "Retinal detachment". BMJ Clinical Evidence. 2014. PMC 3940167. PMID 24807890.
  72. ^ Feltgen, N.; Walter, P. (January 2014). "Rhegmatogenous retinal detachment--an ophthalmologic emergency". Deutsches Ärzteblatt International. 111 (1–2): 12–21, quiz 22. doi:10.3238/arztebl.2014.0012. PMC 3948016. PMID 24565273.
  73. ^ "Toxic Anterior Segment Syndrome After Cataract Surgery". Centers for Disease Control and Prevention. 29 June 2007. from the original on 13 March 2013. Retrieved 18 April 2013.
  74. ^ "Endophthalmitis". Lecturio. from the original on 19 July 2021. Retrieved 19 July 2021.
  75. ^ Bennett, John E. (8 August 2019). "Endophthalmitis". Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases (9th ed.). Elsevier Health Sciences. ISBN 9780323550277.
  76. ^ Gokhale, Parag A.; Patterson, Emory (May–June 2007). "Elevated IOP After Cataract Surgery". Glaucoma today. Bryn Mawr Communications, LLC. from the original on 2023-02-25. Retrieved 2023-02-25.
  77. ^ Swamy, B.N.; Billson, F.; Martin, F.; Donaldson, C.; Hing, S.; Jamieson, R.; Grigg, J.; Smith, J.E. (December 2007). "Secondary glaucoma after paediatric cataract surgery". Br J Ophthalmol. 91 (12): 1627–30. doi:10.1136/bjo.2007.117887. PMC 2095522. PMID 17475699.
  78. ^ a b c d e f g h i j k l m n o Masket, Samuel; Rorer, Eva; Stark, Walter; Holladay, Jack T.; MacRae, Scott; Tarver, Michelle E.; Glasser, Adrian; Calogero, Don; Hilmantel, Gene; Nguyen, Tieuvi; Eydelman, Malvina (January 2017). "Special Report: The American Academy of Ophthalmology Task Force Consensus Statement on Adverse Events with Intraocular Lenses". Ophthalmology. 124 (1): 142–144. doi:10.1016/j.ophtha.2016.09.031. PMID 27726961. from the original on 2023-04-17. Retrieved 2023-02-27.
  79. ^ Gaton, D.D.; Mimouni, K.; Lusky, M.; Ehrlich, R.; Weinberger, D. (September 2003). "Pupillary block following posterior chamber intraocular lens implantation in adults". Br J Ophthalmol. 87 (9): 1109–11. doi:10.1136/bjo.87.9.1109. PMC 1771845. PMID 12928277.
  80. ^ Ou, Yvonne (5 July 2021). "Side Effects of Laser Iridotomy". www.brightfocus.org. University of California, San Francisco. from the original on 23 February 2023. Retrieved 23 February 2023.
  81. ^ Lim, B.X.; Lim, C.H.; Lim, D.K.; Evans, J.R.; Bunce, C.; Wormald, R. (November 2016). "Prophylactic non-steroidal anti-inflammatory drugs for the prevention of macular oedema after cataract surgery". The Cochrane Database of Systematic Reviews. 2016 (11): CD006683. doi:10.1002/14651858.CD006683.pub3. PMC 6464900. PMID 27801522.
  82. ^ Zemba, M.; Camburu, G (2017). "Uveitis-Glaucoma-Hyphaema Syndrome. General review". Romanian Journal of Ophthalmology. 61 (1): 11–17. doi:10.22336/rjo.2017.3. PMC 5710046. PMID 29450365.
  83. ^ a b c Stein, Joshua D.; Grossman, Daniel S.; Mundy, Kevin M.; Sugar, Alan; Sloan, Frank A. (2 June 2011). "Severe Adverse Events after Cataract Surgery Among Medicare Beneficiaries". Ophthalmology. 118 (9): 1716–1723. doi:10.1016/j.ophtha.2011.02.024. PMC 3328508. PMID 21640382. from the original on 7 April 2022. Retrieved 14 February 2023.
  84. ^ a b "Recovery - Cataract surgery". www.nhs.uk. 15 January 2018. from the original on 12 February 2019. Retrieved 12 February 2023.
  85. ^ a b "How Many Days Rest Are Needed After Cataract Surgery?". southcaleye.com. 18 May 2022. from the original on 9 December 2022. Retrieved 22 February 2023.
  86. ^ Dudek, Lara (15 September 2020). "After Cataract Surgery: Dos and Don'ts". from the original on 26 February 2023. Retrieved 22 February 2023.
  87. ^ Sridhar, U.; Tripathy, K. (January 2023). Monofocal Intraocular Lenses. Treasure Island, FL: StatPearls Publishing.
  88. ^ Porter, Daniel (1 August 2022). "When to Resume Exercise After an Eye Surgery or Injury". www.aao.org. American Academy of Ophthalmology. from the original on 28 February 2023. Retrieved 28 February 2023.
  89. ^ Wong, Tien Yin (5 May 2001). "Effect of increasing age on cataract surgery outcomes in very elderly patients". BMJ. 322 (7294): 1104–6. doi:10.1136/bmj.322.7294.1104. PMC 1120237. PMID 11337443.
  90. ^ Hashmi, Farzeen Khalid; Khan, Qazi Assad; Chaudhry, Tanveer Anjum; Ahmad, Khabir (2013). "Visual Outcome of Cataract Surgery" (PDF). Journal of the College of Physicians and Surgeons Pakistan. 23 (6): 448–449. PMID 23763813.
  91. ^ Brogan, K.; Diaper, C.J.; Rotchford, A.P. (2019). "Cataract surgery refractive outcomes: representative standards in a National Health Service setting". British Journal of Ophthalmology. 103 (4): 539–543. doi:10.1136/bjophthalmol-2018-312209. PMID 29907629. S2CID 49219217.
  92. ^ Kugelberg, Maria; Lundström, Mats (May 2009). "Refractive Outcome After Cataract Surgery". Cataract Surgery. CRST Global: Europe Edition. from the original on 2023-04-17. Retrieved 2023-03-03.
  93. ^ Owen, Julia P.; Blazes, Marian; Lacy, Megan; Yanagihara, Ryan T.; Van Gelder, Russell N.; Lee, Aaron Y.; Lee, Cecilia S. (2021). "Refractive Outcomes After Immediate Sequential vs Delayed Sequential Bilateral Cataract Surgery". JAMA Ophthalmol. 139 (8): 876–885. doi:10.1001/jamaophthalmol.2021.2032. PMC 8251655. PMID 34196667. from the original on 2022-10-24. Retrieved 2023-03-03.
  94. ^ Lee, Natalie Si-Yi; Ong, Keith (May 2023). "Changes in refraction after cataract phacoemulsification surgery". Int Ophthalmol. 43 (5): 1545–1551. doi:10.1007/s10792-022-02550-9. PMC 10149444. PMID 36223001.
  95. ^ Jin, Chongfei; Chen, Xinyi; Law, Andrew; Kang, Yunhee; Wang, Xue; Xu, Wen; Yao, Ke (20 September 2017). "Different-sized incisions for phacoemulsification in age-related cataract". Cochrane Database of Systematic Reviews. Cochrane Database Syst Rev. 9 (9:CD010510): CD010510. doi:10.1002/14651858.CD010510.pub2. PMC 5665700. PMID 28931202.
  96. ^ Rose, Aron D. (April 2006). "Bimanual Versus Coaxial". crstoday.com. Cataract and Refractive Surgery Today. Retrieved 21 August 2023.
  97. ^ a b c d Davis, G. (January–February 2016). "The Evolution of Cataract Surgery". Mo. Med. Missouri State Medical Association. 113 (1): 58–62. PMC 6139750. PMID 27039493.
  98. ^ "Chapter 5: Microsurgery and Extracapsular Cataract Extraction" (PDF). rajswasthya.nic.in. pp. 36–44. (PDF) from the original on 6 May 2021. Retrieved 12 February 2023.
  99. ^ Goerig, M.; Bacon, D; van Zundert, A. (May–June 2012). "Carl Koller, cocaine, and local anesthesia: some less known and forgotten facts". Regional Anesthesia and Pain Medicine. 37 (3): 318–24. doi:10.1097/AAP.0b013e31825051f3. PMID 22531385. S2CID 205432874.
  100. ^ Altman, A.J.; Albert, D.M.; Fournier, G.A. (January–February 1985). "Cocaine's use in ophthalmology: our 100-year heritage". Survey of Ophthalmology. 29 (4): 300–6. doi:10.1016/0039-6257(85)90154-7. PMID 3885453.
  101. ^ Meadow, Norman B. (15 October 2005). "Cryotherapy: A fall from grace, but not a crash". Ophthalmology Times.
  102. ^ Pandey, Suresh K.; Milverton, E. John; Maloof, Anthony J. (October 2004). "A tribute to Charles David Kelman MD: ophthalmologist, inventor and pioneer of phacoemulsification surgery". Clinical & Experimental Ophthalmology. 32 (5): 529–533. doi:10.1111/j.1442-9071.2004.00887.x. ISSN 1442-6404. PMID 15498067. S2CID 25230092.
  103. ^ "Two thirds of eye units restricting access to cataract surgery". OnMedica. 10 November 2017. from the original on 10 November 2017. Retrieved 28 December 2017.
  104. ^ "Action on Cataracts Good Practice Guidance" (PDF). NHS Executive via the Royal College of Ophthalmologists. January 2000. (PDF) from the original on 2017-12-30. Retrieved 2017-12-29., referenced in "Context: Guideline for Cataracts in adults". NICE. October 2017. from the original on 2017-12-30. Retrieved 2017-12-29.
  105. ^ "Revealed: The trusts with the highest cataract complication rates". Health Service Journal. 11 October 2019. from the original on 11 October 2019. Retrieved 21 November 2019.
  106. ^ Yusufu, Mayinuer; Bukhari, Javaria; Yu, Xiaobin; Lin, Timothy P.H.; Lam, Dennis S.C.; Wang, Ningli (September–October 2021). "Challenges in Eye Care in the Asia-Pacific Region". Asia-Pacific Journal of Ophthalmology. 10 (5): 423–429. doi:10.1097/APO.0000000000000391. PMID 34516436. S2CID 237505240.
  107. ^ Du, Y.F.; Liu, H.R.; Zhang, Y.; Bai, W.L.; Li, R.Y.; Sun, R.Z.; Wang, N.L. (18 January 2022). "Prevalence of cataract and cataract surgery in urban and rural Chinese populations over 50 years old: a systematic review and Meta-analysis". Int J Ophthalmol. 15 (1): 141–149. doi:10.18240/ijo.2022.01.21. PMC 8720354. PMID 35047369.
  108. ^ a b Vs Murthy, G.; Jain, B.; Shamanna, B; Subramanyam, D. (2014). "Improving cataract services in the Indian context". Community Eye Health. 27 (85): 4–5. PMC 4069775. PMID 24966453.
  109. ^ a b Barnagarwala, Tabassum (23 February 2022). "When India's mass eye camps leave people blind". Scroll.in. from the original on 23 February 2023. Retrieved 23 February 2023.
  110. ^ Mabiyan, Rashmi (25 October 2017). "Cataract prevalent in India despite largest number of surgeries: Dr Mahipal S Sachdev, Centre for Sight". from the original on 23 February 2023. Retrieved 23 February 2023.
  111. ^ Wong, T.Y. (October 2005). "Cataract surgery programmes in Africa". The British Journal of Ophthalmology. 89 (10): 1231–1232. doi:10.1136/bjo.2005.072645. PMC 1772878. PMID 16170103.
  112. ^ Aboobaker, S.; Courtright, P. (January–March 2016). "Barriers to Cataract Surgery in Africa: A Systematic Review". Middle East Afr J Ophthalmol. 23 (1): 145–9. doi:10.4103/0974-9233.164615. PMC 4759895. PMID 26957856.
  113. ^ The Epidemic of Cataracts in sub-Saharan Africa (PDF). www.embracerelief.org (Report). (PDF) from the original on 14 March 2023. Retrieved 24 February 2023.
  114. ^ Lewallen, S.; Courtright, P; Etya'ale, D.; Mathenge, W.; Schmidt, E; Oye, J.; Clark, A; Williams, T. (October 2013). "Cataract incidence in sub-Saharan Africa: what does mathematical modeling tell us about geographic variations and surgical needs?". Ophthalmic Epidemiol. 20 (5): 260–6. doi:10.3109/09286586.2013.823215. PMID 24070099. S2CID 32828934.
  115. ^ Babalola, O.E. (December 2011). "The peculiar challenges of blindness prevention in Nigeria: a review article". Afr J Med Med Sci. 40 (4): 309–19. PMID 22783680.
  116. ^ "Speedy Eye Surgery for Cataract Patients". www.westerncape.gov.za. Department of Health and Wellness (Western Cape Government). 20 July 2016. from the original on 25 February 2023. Retrieved 25 February 2023.
  117. ^ "Supporting cataract surgery backlog for Mandela Day 2023". www.lifehealthcare.co.za. 18 July 2023. from the original on 13 August 2023. Retrieved 13 August 2023.
  118. ^ "The gift of sight". Mediclinic: The Future of Healthcare. 29 Oct 2019. from the original on 27 June 2022. Retrieved 13 August 2023.
  119. ^ "Pretoria Eye Institute gives 70 patients the gift of sight". www.eyeinstitute.co.za. from the original on 25 February 2023. Retrieved 25 February 2023.
  120. ^ a b c Lecuona, K.; Cook, C. (2011). "South Africa's cataract surgery rates: why are we not meeting our targets?" (PDF). South African Medical Journal. 101 (8): 510–512. PMID 21920119. (PDF) from the original on 2023-02-26. Retrieved 2023-02-26.
  121. ^ Lansingh, Van C.; Resnikoff, Serge; Tingley-Kelley, Kimberly; Nano, María E.; Martens, Marion; Silva, Juan C.; Duerksen, Rainald; Carter, Marissa J. (19 March 2010). "Cataract Surgery Rates in Latin America: A Four-Year Longitudinal Study of 19 Countries". Ophthalmic Epidemiology. 17 (2): 75–81. doi:10.3109/09286581003624962. PMID 20302429. S2CID 38013312. from the original on 4 March 2023. Retrieved 4 March 2023.
  122. ^ Batlle, Juan Francisco; Lansingh, Van Charles; Silva, Juan Carlos; Eckert, Kristen Allison; Resnikoff, Serge (2014). "The Cataract Situation in Latin America: Barriers to Cataract Surgery". American Journal of Ophthalmology. 158 (2): 242–250. doi:10.1016/j.ajo.2014.04.019. ISSN 0002-9394. PMID 24792101.
  123. ^ Limburg, H.; Silva, J.C.; Foster, A. (2009). Cataract in Latin America: findings from nine recent surveys (PDF) (Report). Vol. 25. Rev Panam Salud Publica. pp. 449–55. (PDF) from the original on 2021-09-09. Retrieved 2023-03-04.
  124. ^ "Social and Economic Impacts of Restoring Sight". www.hollows.org. The Fred Hollows Foundation. 7 April 2017. from the original on 25 March 2023. Retrieved 25 March 2023.
  125. ^ Finger, R.P.; Kupitz, D.G.; Fenwick, E.; Balasubramaniam, B.; Ramani, R.V.; Holz, F.G.; Gilbert, C.E. (August 2012). "The impact of successful cataract surgery on quality of life, household income and social status in South India". PLOS ONE. 7 (8): e44268. Bibcode:2012PLoSO...744268F. doi:10.1371/journal.pone.0044268. PMC 3432104. PMID 22952945.
  126. ^ a b Foster, Allen, ed. (2000). "Vision 2020: the cataract challenge". Community Eye Health. 13 (34): 17–19. PMC 1705965. PMID 17491949.
  127. ^ "Vision 2020". www.aao.org. American Academy of Ophthalmology. from the original on 5 March 2023. Retrieved 5 March 2023.
  128. ^ "VISION 2020". www.iapb.org. International Agency for the Prevention of Blindness. from the original on 7 March 2023. Retrieved 5 March 2023.
  129. ^ a b c Abdulhussein, Dalia; Hussein, Mina Abdul (30 September 2022). "WHO Vision 2020: Have We Done It?". Ophthalmic Epidemiology. 30 (4): 331–339. doi:10.1080/09286586.2022.2127784. PMID 36178293. S2CID 252621547.
  130. ^ "Facts About Cataract". nei.nih.gov. National Eye Institute. from the original on 2017-10-14. Retrieved 2017-10-18.
  131. ^ a b Struck, M.C. (October 2015). "Long-term Results of Pediatric Cataract Surgery and Primary Intraocular Lens Implantation From 7 to 22 Months of Life". JAMA Ophthalmol. 133 (10): 1180–1183. doi:10.1001/jamaophthalmol.2015.2062. PMID 26111188.
  132. ^ Monahan, Patrick (9 March 2016). "Eyes can regenerate their own lenses after cataract surgery". Science. from the original on 10 March 2023. Retrieved 10 March 2023.
  133. ^ Lin, Haotian; Ouyang, Hong; Zhu, Jie; Huang, Shan; Liu, Zhenzhen; Chen, Shuyi; Cao, Guiqun; Li, Gen; Signer, Robert A. J.; Xu, Yanxin; Chung, Christopher; Zhang, Ying; Lin, Danni; Patel, Sherrina; Wu, Frances; Cai, Huimin; Hou, Jiayi; Wen, Cindy; Jafari, Maryam; Liu, Xialin; Luo, Lixia; Zhu, Jin; Qiu, Austin; Hou, Rui; Chen, Baoxin; Chen, Jiangna; Granet, David; Heichel, Christopher; Shang, Fu; Li, Xuri; Krawczyk, Michal; Skowronska-Krawczyk, Dorota; Wang, Yujuan; Shi, William; Chen, Daniel; Zhong, Zheng; Zhong, Sheng; Zhang, Liangfang; Chen, Shaochen; Morrison, Sean J.; Maas, Richard L.; Zhang, Kang; Liu, Yizhi (9 March 2016). "Lens regeneration using endogenous stem cells with gain of visual function". Nature. 531 (7594): 323–328. Bibcode:2016Natur.531..323L. doi:10.1038/nature17181. PMC 6061995. PMID 26958831. S2CID 4397702.
  134. ^ Alió, Jorge L.; Nowrouzi, Ali (29 August 2022). "Immediately sequential bilateral cataract surgery importance during the COVID-19 pandemic". Saudi Journal of Ophthalmology. 36 (2): 124–128. doi:10.4103/sjopt.sjopt_131_22 (inactive 1 August 2023). PMC 9535909. PMID 36211314.{{cite journal}}: CS1 maint: DOI inactive as of August 2023 (link)
  135. ^ Obuchowska, I; Mariak, Z. (2006). "Jednoczesna operacja zaćmy w obojgu oczach--zalety i wady [Simultaneous bilateral cataract surgery--advantages and disadvantages]". Klin Oczna (in Polish). 108 (7–9): 353–6. PMID 17290841.
  136. ^ "Cataract surgery". www.rvc.ac.uk. London, UK: Royal Veterinary College. Retrieved 11 December 2023.
  137. ^ Bayley, Kellam D.; Gates, M. Carolyn; Anastassiadis, Zoe; Read, R.A. (18 May 2023). "The use of sub-Tenon's anesthesia versus a low-dose neuromuscular blockade for canine cataract surgery: A comparative study of 224 eyes". Veterinary Ophthalmology. doi:10.1111/vop.13111.
  138. ^ Barsam, Allon; Allan, Bruce (17 July 2014). "Excimer laser refractive surgery versus phakic intraocular lenses for the correction of moderate to high myopia". Cochrane Database of Systematic Reviews (6): CD007679. doi:10.1002/14651858.cd007679.pub4. ISSN 1465-1858. PMID 24937100.

Further reading edit

  • Frampton G, Harris P, Cooper K, Lotery A, Shepherd J (November 2014). "The clinical effectiveness and cost-effectiveness of second-eye cataract surgery: a systematic review and economic evaluation". Health Technology Assessment. NIHR Journals Library. 18 (68): 1–205, v–vi. doi:10.3310/hta18680. PMC 4781176. PMID 25405576. 18.68.
  • Prajna NV, Ravilla TD, Srinivasan S (2015). "Ch: 11. Cataract Surgery". In Debas HT, Donkor P, Gawande A, Jamison DT, Kruk ME, Mock CN (eds.). Essential Surgery. Disease Control Priorities. Vol. 1 (3rd ed.). The International Bank for Reconstruction and Development / The World Bank. doi:10.1596/978-1-4648-0346-8. hdl:10986/21568. ISBN 978-1-4648-0346-8. PMID 26740991. from the original on 2022-01-19. Retrieved 2017-08-16.
  • Tasman, William, ed. (2006). "Duane's Ophthalmology". Lippincott Williams & Wilkins. from the original on 2022-11-27. Retrieved 2023-02-19 – via www.oculist.net.

External links edit

  • Youtube video of phacoemulification technique

December 15, 2023
cataract, surgery, also, called, lens, replacement, surgery, removal, natural, lens, that, developed, cataract, opaque, cloudy, area, natural, lens, usually, replaced, with, artificial, intraocular, lens, implant, using, temporal, approach, phacoemulsification. Cataract surgery also called lens replacement surgery is the removal of the natural lens of the eye that has developed a cataract an opaque or cloudy area 1 The eye s natural lens is usually replaced with an artificial intraocular lens IOL implant 2 Cataract surgeryCataract surgery using a temporal approach phacoemulsification probe in right hand and chopper in left hand SpecialtyOphthalmologyICD 9 CM13 19MeSHD002387MedlinePlus002957 edit on Wikidata Over time metabolic changes of the crystalline lens fibres lead to the development of a cataract causing impairment or loss of vision Some infants are born with congenital cataracts and environmental factors may lead to cataract formation Early symptoms may include strong glare from lights and small light sources at night and reduced visual acuity at low light levels 3 4 During cataract surgery the cloudy natural lens is removed from the posterior chamber either by emulsification in place or by cutting it out 2 An IOL is usually implanted in its place PCIOL or less frequently in front of the chamber to restore useful focus Cataract surgery is generally performed by an ophthalmologist in an out patient setting at a surgical centre or hospital Local anaesthesia is normally used the procedure is usually quick and causes little or no pain and minor discomfort Recovery sufficient for most daily activities usually takes place in days and full recovery about a month 5 Well over 90 of operations are successful in restoring useful vision and there is a low complication rate Day care high volume minimally invasive small incision phacoemulsification with quick post operative recovery has become the standard of care in cataract surgery in the developed world 2 Manual small incision cataract surgery MSICS which is considerably more economical in time capital equipment and consumables but provides comparable results is popular in the developing world 6 Both procedures have a low risk of serious complications 7 8 and are the definitive treatment for vision impairment due to lens opacification 9 Contents 1 Uses 2 Techniques 3 Pre operative evaluation 3 1 Contraindications 3 2 Selection of intraocular lenses 4 Operation procedures 4 1 Preparation 4 2 Anaesthesia 4 3 Phacoemulsification 4 4 Manual small incision cataract surgery MSICS 4 5 Extracapsular cataract extraction 4 6 Converting to ECCE to manage a contingency 4 7 Closing the wound 5 Post operative care 6 Complications 6 1 During surgery 6 2 After surgery 6 3 Risk 7 Recovery and rehabilitation 8 Outcomes 9 History 10 Regional practice and statistics 10 1 United Kingdom 10 2 Asia 10 2 1 China 10 2 2 India 10 3 Africa 10 3 1 Nigeria 10 3 2 South Africa 10 4 Latin America 11 Social and economic relevance 12 Special populations 12 1 Congenital cataracts 12 2 Developing world 12 3 Higher risk for operations on separate occasions 13 Other animals 14 See also 15 Notes 16 References 17 Further reading 18 External linksUses editSee also Cataract nbsp Magnified view of a cataract seen on examination with a slit lampCataract surgery is the most common application of lens removal surgery and is usually associated with lens replacement It is used to remove the natural lens of the eye when it has developed a cataract a cloudy area in the lens that causes visual impairment 4 10 Cataracts usually develop slowly and can affect one or both eyes 4 Early symptoms may include faded colours blurred or double vision halos around lights sensitivity to glare from bright lights and night blindness Blindness is the end result 4 The procedure is normally elective but lens removal may be part of trauma surgery in cases where the eye is severely injured The lens is usually replaced by an intraocular implant when this is reasonably practicable as removal of the lens also removes the ability of the eye to focus at any distance 2 Cataracts most commonly occur due to aging but may also be caused by trauma or radiation exposure be present since birth or may develop as a complication of eye surgery intended to solve other health problems 4 11 Cataracts form when clumps of proteins or yellow brown pigment accumulate in the lens which reduces transmission of light to the retina at the back of the eye 4 Cataracts can be diagnosed via an eye examination 4 Early symptoms of cataract may be improved by wearing specific types of glasses if this does not help cataract surgery is the only effective treatment 4 Surgery with implants generally results in better vision and an improved quality of life however the procedure is not readily available in many countries 4 11 12 13 Techniques edit nbsp Cataract surgery using a surgical microscope nbsp Cataract surgery recently performed foldable IOL inserted A small incision and very slight hemorrhage are visible to the right of the still dilated pupil nbsp Nucleus of a mature cataract removed by ECCETwo main classes of cataract surgical procedures are currently in common use throughout the world phacoemulsification and extracapsular cataract extraction Intracapsular cataract extraction has been superseded where the facilities for surgery under a microscope are available except for cases where the lens capsule cannot be retained and couching is no longer used in mainstream medicine In phacoemulsification phaco the natural lens is fragmented by an ultrasonic probe and removed by suction A more recent and less common variation of this Femtosecond laser assisted phacoemulsification surgery uses a laser to make the corneal incision execute the capsulotomy which provides access to the lens and initiate lens fragmentation which reduces energy requirements for phacoemulsification 7 The small incision size used in phacoemulsification generally allows for sutureless incision closure 7 In extracapsular cataract extraction ECCE and its variation manual small incision cataract surgery MSICS the lens is removed from its capsule and manually extracted from the eye either whole or after being split into a small number of substantial pieces 9 The basic version of ECCE uses a larger incision of 10 12 mm 0 39 0 47 in and usually requires stitches This requirement led to the variation known as MSICS which does not usually need stitches as the incision should be self sealing under internal pressure due to its geometry 2 Comparative trials of MSICS against phaco in dense cataracts have found no significant difference in outcomes although MSICS had shorter operating times and significantly lower costs 6 MSICS has been prioritized as the method of choice in developing countries because it provides high quality outcomes with less surgically induced astigmatism than standard ECCE no suture related problems quick rehabilitation and fewer post operative visits MSICS is generally easy and fast to learn for the surgeon cost effective and applicable to almost all types of cataract 8 ECCE using a large incision has largely become a contingency procedure to deal with complications during surgery and for managing cataracts expected to be difficult extractions 14 In most surgeries an IOL is inserted Foldable lenses are generally used for the 2 3 mm 0 08 0 12 in phaco incision while non foldable lenses can be placed through the larger extracapsular incision Intracapsular cataract extraction ICCE is the removal of the lens and the surrounding lens capsule in one piece The procedure has a relatively high rate of complications in comparison to techniques in which the capsule is retained in place due to the large incision required pressure placed on the vitreous body when removing the encapsulated lens and the removal of the barrier between the chambers of the eye allowing easier migration of vitreous into the anterior chamber It has therefore been largely superseded and is rarely performed in countries where operating microscopes and high technology equipment are readily available 2 After lens removal by ICCE an intraocular lens implant can be placed in either the anterior chamber or sutured into the ciliary sulcus Note 1 7 Cryoextraction is a technique used in ICCE to extract the lens using a cryoprobe the refrigerated tip of which adheres to the tissue of the lens at the contact point by freezing with a cryogenic substance such as liquid nitrogen facilitating its removal 15 Cryoextraction may still be used for the removal of subluxated partially dislocated lenses 16 Couching is the earliest documented form of cataract surgery It involves dislodging the lens of the eye removing the cataract from the optical axis but leaving it inside the eye The lens is not replaced and the eye cannot focus at any distance 17 Phacoemulsification is the most commonly performed cataract procedure in the developed world 18 but the high capital and maintenance costs of a phacoemulsification machine and of the associated disposable equipment have made ECCE and MSICS the most commonly performed procedures in developing countries 2 Cataract surgery is commonly done as an out patient or day care procedure which is cheaper than hospitalisation and an overnight stay and day surgery has similar medical outcomes 19 Pre operative evaluation editAn eye examination or pre operative evaluation is done to confirm the presence of a cataract and to determine the patient s suitability for surgery 2 The degree of reduction of vision due largely to the cataract is evaluated While the existence of other sight threatening diseases such as age related macular degeneration or glaucoma does not preclude cataract surgery less improvement may be expected in their presence 2 In cases of uncontrolled glaucoma a combined cataract glaucoma procedure phaco trabeculectomy can be planned and performed 20 The pupil is checked for dilation using eyedrops if pharmacologic pupil dilation is insufficient procedures for mechanical pupil dilatation may be needed during the surgery 21 People with retinal detachment may be scheduled for a combined vitreo retinal procedure along with IOL implantation 22 People taking tamsulosin Flomax a common drug for enlarged prostate are prone to developing a surgical complication known as intraoperative floppy iris syndrome IFIS which requires appropriate management to avoid posterior capsule rupture Note 2 23 A Cochrane Review of three randomized clinical trials including over 21 500 cataract surgeries examined whether routine pre operative medical testing resulted in a reduction of adverse events during surgery Results showed performing pre operative medical testing did not result in a reduction of risk of intra operative or post operative medical adverse events compared to surgeries with no or limited pre operative testing 24 Infants with congenital cataracts are more likely to have post operative inflammation problems 25 and their eyes grow rapidly and unpredictably making it challenging to select and fit a posterior chamber IOL in infants younger than seven months that will give satisfactory results later in childhood A second surgery may be required later 26 Contraindications edit Contraindications to cataract surgery include cataracts that do not cause visual impairment and medical conditions that predict a high risk of unsatisfactory surgical outcomes 2 such as Poor general health or a serious medical condition 27 Surgery will not provide better visual function 28 Advanced macular degeneration 27 Detached retina 27 Advanced diabetes that has affected the retina 27 An infection of the eyes or nearby that could cause endophthalmitis so should be treated before cataract surgery 28 The person does not want surgery 28 Functional vision can be provided by glasses or other visual aids which is sufficient for the person s requirements 28 Corneal diseases such as glaucoma may be a relative contraindication 27 Selection of intraocular lenses edit Main article Intraocular lens nbsp 18 5 diopter foldable intraocular lens nbsp Injector for foldable intraocular lenses The incision size for this type is 2 8mm nbsp The IOL injector is inserted in the incision and aimed at the capsule nbsp The rolled up lens is ejected from the nozzle into the capsule nbsp The lens unfolds in place nbsp Section diagram of the eye showing intraocular lens implanted in the posterior lens capsule behind the irisAfter the removal of a cataract an intraocular lens is usually implanted to replace the damaged natural lens A foldable IOL may be implanted through a 1 8 to 2 8 mm 0 071 to 0 110 in incision whereas a rigid poly methyl methacrylate PMMA lens requires a larger cut Foldable IOLs are made of silicone hydrophobic or hydrophilic acrylic material of appropriate refractive power and are inserted with a special tool 29 The IOL is inserted through the incision usually into the capsular bag from which the cararact was removed in the bag implantation Sometimes a sulcus implantation in front of the capsular bag but behind the iris may be required because of posterior capsular tears or zonular dialysis inadequate support for the capsular bag This requires an IOL with different refractive power because of the placement further forward on the optical axis 30 The appropriate refractive power of the IOL is selected much like a spectacle or contact lens prescription to provide the desired refractive outcome Pre operative measurements including corneal curvature axial length and white to white measurements Note 3 are used to estimate the required power of the IOL These methods include several formulae and free online calculators which use similar input data 31 A history of LASIK surgery which alters corneal curvature requires different calculations to take this into account 31 Monofocal IOLs provide accurately focused vision at one distance only far intermediate or near People who are fitted with these lenses may need to wear glasses or contact lenses while reading or using a computer These lenses usually have uniform spherical curvature 32 Other designs of multifocal intraocular lens that focus light from distant and near objects working with similar effect to bifocal or trifocal eyeglasses are also available Pre operative patient selection and good counselling is necessary to avoid unrealistic expectations and post operative patient dissatisfaction and possibly a requirement to replace the lens 33 Acceptability of these lenses has improved and studies have shown good results in patients selected for expected compatibility 34 Cataract surgery may be performed to correct vision problems on both eyes If both eyes are suitable people are usually advised to consider monovision This procedure involves inserting an IOL providing near vision into one eye while using one that provides distance vision for the other eye Although most people can adjust to having monofocal IOLs with differing focal length some cannot compensate and may experience blurred vision at both near and far distances An IOL optimised for distance vision may be combined with an IOL that optimises intermediate vision instead of near vision as a variation of monovision 29 One model of lens designed to change focus using the natural reflexes of the eye has two hinged struts on opposite edges which displace the lens along the optical axis when an inward transverse force is applied to the haptic loops at the outer ends of the struts the components transferring the movement of the contact points to the device while recoiling when the same force is reduced The lens is implanted in the eye s lens capsule where the contractions of the ciliary body which would focus the eye with the natural lens are used to focus the implant instead 2 35 IOLs used in correcting astigmatism have different curvature on two orthogonal axes as on the surface of a torus for this reason they are called toric lenses Intraoperative aberrometry Note 4 can be used to assist the surgeon in toric lens placement and minimize astigmatic errors 36 37 The first aspheric IOLs were developed in 2004 they have a flatter periphery than the middle of the lens improving contrast sensitivity The effectiveness of aspheric IOLs depends on a range of conditions and they may not always provide significant benefit 38 Some IOLs are able to absorb ultraviolet and high energy blue light thus mimicking the functions of the natural crystalline lens of the eye which usually filters potentially harmful frequencies A 2018 Cochrane review found there is unlikely to be a significant difference in distance vision between blue filtering and plain lenses and was unable to identify a difference in contrast sensitivity or colour discrimination 39 40 The light adjustable IOL was approved by the U S Food and Drug Administration FDA in 2017 41 This type of IOL is implanted in the eye and then treated with ultraviolet light to alter the curvature of the lens before fixing it at the final strength 42 In some cases it may be necessary or desirable to insert an additional lens over the already implanted one also in the posterior capsule This type of IOL placement is called piggyback IOLs and is usually considered when the visual outcome of the first implant is not optimal 43 In such cases implanting another IOL over the existing one is considered safer than replacing the initial lens This approach may also be used in people who need high degrees of vision correction 44 Cost is an important aspect of these lenses Although Medicare covers the cost of monofocal IOLs in the United States people will have to pay the price difference if they choose more expensive lenses 45 Operation procedures editPreparation edit Preparation may begin three to seven days before surgery with the pre operative application of NSAIDs and antibiotic eyedrops 8 If the IOL is to be placed behind the iris the pupil is dilated by using drops to help better visualise the cataract Pupil constricting drops are reserved for secondary implantation of the IOL in front of the iris when the cataract has already been removed without primary IOL implantation 46 The operation may occur on a stretcher or a reclining examination chair The eyelids and surrounding skin are swabbed with a disinfectant such as 10 povidone iodine and topical povidone iodine is applied to the eye The face is covered with a cloth or sheet with an opening for the operative eye The eyelid is held open with a speculum to minimize blinking during surgery 47 Pain is usually minimal in properly anaesthetised eyes though a pressure sensation and discomfort from the bright operating microscope light is common 7 Anaesthesia edit Most cataract operations are performed under local anaesthetic allowing the patient to return home the same day Lens and cataract procedures are commonly performed in an out patient setting in the United States 99 9 of lens and cataract procedures were done in an out patient setting by 2012 48 Topical sub tenon peribulbar or retrobulbar local anaesthesia is generally used usually causing little or no discomfort 49 46 Injections may be used to block regional nerves and prevent eye movement 7 Topical anaesthetics are most commonly used placed on the globe of the eye as eyedrops before surgery or in the globe during surgery 46 Oral or intravenous sedation to reduce anxiety may be combined with the local anaesthetic General anaesthesia and retrobulbar blocks were historically used for intracapsular cataract surgery and may be used for children and adults whose medical or psychiatric issues significantly affect their ability to remain still during the procedure 7 46 Phacoemulsification edit Main article Phacoemulsification Phacoemulsification uses a machine with an ultrasonic handpiece with a titanium or surgical stainless steel tip which vibrates at an ultrasonic frequency commonly 40 kHz to emulsify the lens tissue which is aspirated by a coaxial annular suction tube A second instrument which is sometimes called a cracker or chopper may be used from a small side incision to break the hard cataract nucleus into smaller pieces making emulsification and removal of the soft part of the lens around the nucleus easier After phacoemulsification of the lens nucleus and cortical material is completed an irrigation aspiration I A system is used to remove the remaining peripheral lens material The procedure is done under a surgical microscope 7 Femtosecond laser assisted phacoemulsification surgery is a more recent development which may have fewer adverse effects on the cornea and macula than manual phacoemulsification The laser is used to make the corneal incision and the capsulotomy which provides access to the lens and initiate lens fragmentation which reduces energy requirements for phacoemulsification It offers high precision effective lens fragmentation at lower power levels and good optical quality However as of 2022 the technique has not been shown to have significant visual refractive or safety benefits over manual phacoemulsification and it has a higher cost 2 50 51 Entry into the eye is made through a minimal tunnel incision near the edge of the cornea 7 The incision for cataract surgery has evolved along with the techniques for cataract removal and IOL placement In phacoemulsification the width depends on the requirements for IOL insertion With foldable IOLs it is often possible to use incisions smaller than 3 5 mm 0 14 in The shape position and size of the incision affect the capacity for self sealing the tendency to induce astigmatism and the surgeon s ability to maneuvre instruments through the opening 52 A more posterior incision simplifies wound closure and decreases induced astigmatism but it is more likely to damage blood vessels nearby 7 One or two smaller side port incisions at 60 to 90 degrees from the main incision may be needed to access the anterior chamber with additional instruments 47 Ophthalmic viscosurgical devices OVDs a class of clear gel like materials are injected into the anterior chamber at the start of the procedure to support stabilize and protect the eyeball to help maintain eye shape and volume and to distend the lens capsule during IOL implantation 53 Their consistency allows surgical instruments to move through them although they do not flow and retain their shape under low shear stress The OVD will also constrain lens fragments from drifting around in the chamber OVDs are available in several formulations which may be combined or used individually as best suits the procedure 7 The lens is inside a capsule supported by the ciliary body between the aqueous and vitreous behind the opening in the iris Capsulorhexis is the process of tearing a circular opening in the front membrane of the lens capsule to access the lens within In phacoemulsification an anterior continuous curvilinear capsulorhexis is usually used to create a round smooth edged opening through which the surgeon can emulsify the lens nucleus and then implant the intraocular lens 54 The cataract s outer cortical layer is then separated from the capsule by a gentle continuous flow or pulsed dose of liquid from a cannula which is injected under the anterior capsular flap along the edge of the capsulorhexis opening in a step called hydrodissection 55 56 In hydrodelineation fluid is injected into the body of the lens through the cortex against the nucleus of the cataract which separates the hardened nucleus from the softer cortex shell by flowing along the interface between them As a result the smaller hard nucleus can be more easily emulsified The posterior cortex serves as a buffer at this stage protecting the posterior capsule membrane The smaller size of the separated nucleus allows it to be broken up using shallower and less peripheral grooving by the phaco tip and produces smaller fragments after cracking or chopping The posterior cortex also maintains the shape of the capsule through this stage which reduces the risk of posterior capsule rupture 57 After nuclear cracking or chopping if needed the cataract is reduced to small fragments using ultrasound which are simultaneously aspirated The remaining lens cortex outer layer of lens material from the capsular bag is carefully aspirated and if necessary the remaining epithelial cells from the capsule are removed by capsular polishing 58 The folded intraocular replacement lens is implanted usually into the remaining posterior capsule and checked hat it has unfoldded and seated correctly A toric IOL must also be aligned in the correct axis to counteract astigmatism 2 Manual small incision cataract surgery MSICS edit Many of the steps followed during MSICS are similar if not identical to those for phacoemulsification the main differences are related to the alternative method of incision and cataract extraction from the capsule and eye Manual small incision cataract surgery MSICS is an evolution of ECCE the lens is removed from the eye through a self sealing tunnel wound through the sclera A well constructed scleral tunnel is held closed by internal pressure is watertight and does not require suturing The wound is relatively smaller than the one in ECCE but is still markedly larger than a phaco wound The small incision into the anterior chamber of the eye is made at or near the corneal limbus where the cornea and sclera meet either superior or temporal 8 Advantages of the smaller incision include use of few to no stitches and shortened recovery time 2 The MSICS incision is small in comparison with the earlier ECCE incision but considerably larger than the one used in phacoemulsification The precise geometry of the incision is important as it affects the self sealing of the wound and the amount of astigmatism induced by distortion of the cornea during healing A sclerocorneal or scleral tunnel incision is commonly used since it reduces the risk of induced astigmatism if suitably formed 6 47 A sclerocorneal tunnel a three phase incision starts with a shallow incision perpendicular to the sclera followed by an incision through the sclera and cornea approximately parallel to the outer surface and then a beveled incision into the anterior chamber This structure provides the self sealing characteristic because internal pressure presses together the faces of the incision 8 Bridle sutures Note 5 may be used to help stabilize the eyeball during sclerocorneal tunnel incision and during extraction of the nucleus and epinucleus through the tunnel 8 The depth of the anterior chamber and position of the posterior capsule may be maintained during surgery by OVDs or an anterior chamber maintainer which is an auxiliary cannula providing a sufficient flow of buffered saline solution BSS to maintain stability of the shape of the chamber and internal pressure 59 60 An anterior capsulotomy is then done to open the front surface of the lens capsule for access to the lens 61 The continuous curvilinear capsulorhexis technique is often used or can opener capsulotomy and envelope capsulotomy 59 The cataract lens is then removed from the capsule and anterior chamber using hydroexpression Note 6 viscoexpression Note 7 or more direct mechanical methods 59 62 63 Following cataract removal an IOL is usually inserted into the posterior capsule 7 When the posterior membrane of the capsule is damaged the IOL may be inserted into the ciliary sulcus 30 or a glued intraocular lens technique may be applied 64 Extracapsular cataract extraction edit Extracapsular cataract extraction ECCE also known as manual extracapsular cataract extraction is the removal of almost the entire natural lens in one piece while most of the elastic lens capsule posterior capsule is left intact to allow implantation of an intraocular lens 2 The lens is manually removed through a 10 12 mm 0 39 0 47 in incision in the cornea or sclera Although it requires a larger incision and the use of stitches this method may be preferable for very hard cataracts which would require a relatively large ultrasonic energy input which causes more heating as well as in other situations in which phacoemulsification is problematic 14 Converting to ECCE to manage a contingency edit The most commonly used procedures are phacoemulsification and manual small incision cataract surgery MSICS In either of these procedures it can sometimes be necessary to convert to ECCS to deal with a problem better managed through a larger incision 14 This may occur in the event of posterior capsule rupture zonular dehiscence Note 8 a dropped nucleus Note 9 with a nuclear fragment more than half the size of the cataract 14 problematic capsulorhexis with a hard cataract 14 or a very dense cataract where the heat developed by phacoemulsification is likely to cause permanent damage to the cornea 14 Similarly a change from MSICS to ECCE is appropriate whenever the nucleus is too large for the MSICS incision 14 as well as in cases where the nucleus is found to be deformed during MSICS on a nanophthalmic eye Note 10 14 Closing the wound edit After the IOL is inserted OVDs that were injected to stabilize the anterior chamber protecting the cornea from damage and distending the cataract s capsule during IOL implantation are removed from the eye to prevent post operative viscoelastic glaucoma a severe intra ocular pressure increase This is done via suction from the irrigation aspiration instrument and replacement by buffered saline solution BSS Cohesive OVDs tend to adhere to themselves a characteristic that makes their removal easier 53 Removal of OVDs from behind the implant reduces the risk and magnitude of post operative pressure spikes or capsular distention 7 In the final step the wound is sealed by increasing the pressure inside the globe with BSS which presses the internal tissue against the external tissue of the incision holding it closed The surgeon will check whether the incision leaks fluid because wound leakage increases the risk of penetration into the eye by microorganisms thus predisposing it to endophthalmitis If this does not achieve a satisfactory seal a suture may be added The wound is then hydrated an antibiotic steroid combination eyedrop is put in and an eye shield may be applied sometimes supplemented with an eyepatch 7 Post operative care editThe use of an eye patch may be indicated usually for some hours after surgery and for a few days while sleeping A topical corticosteroid or nonsteroidal anti inflammatory drug NSAID is used to control inflammation in combination with topical antibiotics to prevent infection in the post operative phase These are generally self administered as eyedrops for a few weeks 7 Complications editDuring surgery edit Posterior capsular rupture a tear in the posterior capsule of the natural lens is the most common complication during cataract surgery with its rate ranging from 0 5 to 5 2 2 Surgical management may involve anterior vitrectomy and occasionally alternative planning for implanting the IOL either in the ciliary sulcus the space between the iris and the ciliary body in the anterior chamber in front of the iris or less commonly sutured to the sclera Posterior capsule rupture can cause lens fragments to be retained corneal oedema and cystoid macular oedema it is also associated with a six times increase in the risk of endophthalmitis and as much as a nineteen times increase in the risk of retinal detachment 2 65 Management methods include the Intraocular lens scaffold procedure 66 Suprachoroidal hemorrhage is a rare complication of intraocular surgery which occurs when damaged ciliary arteries bleed into the space between the choroid and the sclera 67 It is a potentially vision threatening pathology Risk factors for suprachoroidal hemorrhage include anterior chamber intraocular lens ACIOL axial myopia advanced age atherosclerosis glaucoma systolic hypertension tachycardia uveitis and previous ocular surgery Suprachoroidal hemorrhage must be treated immediately and effectively in order to preserve visual functions 7 Intraoperative floppy iris syndrome has an incidence ranging from around 0 5 to 2 0 2 Iris or ciliary body injury has an incidence of about 0 6 1 2 2 In the event of a posterior capsule rupture fragments of the nucleus can find their way through the tear into the vitreous chamber this is called posterior dislocation of nuclear fragments Recovery of the fragments is not always desirable and it is rarely successful The rest of the fragments should generally be stabilised first and vitreous needs to be prevented from entering the anterior chamber Removal of the fragments may be best referred to a vitreoretinal specialist 7 Other complications include failure to aspirate all lens fragments leaving some in the anterior chamber 65 and incisional burns caused by overheating of the phacoemulsification tip when ultrasonic power continues while the irrigation or aspiration lines are blocked the flow through these lines is used to keep the tip cool Burns to the incision may make closure difficult and can cause corneal astigmatism 7 After surgery edit nbsp Slit lamp photo of IOL showing Posterior capsular opacification PCO visible a few months after implantation of intraocular lens in eye seen on retroilluminationComplications after cataract surgery are relatively uncommon Posterior vitreous detachment PVD does not directly threaten vision but its cases are monitored with increasing interest since the interaction between the vitreous body and the retina might play a decisive role in the development of major pathological vitreoretinal conditions PVD may be more problematic with younger patients because many people older than 60 have already gone through PVD PVD may be accompanied by peripheral light flashes and increasing numbers of floaters 68 Some people develop posterior capsular opacification PCO also called an after cataract After cataract surgery posterior capsular cells usually undergo hyperplasia and cellular migration as part of a physiological change showing up as a thickening opacification and clouding of the posterior lens capsule which is left behind after the cataract is removed for placement of the IOL This may compromise visual acuity and can usually be safely and painlessly corrected by using a Nd YAG laser to clear the central portion of the opacified posterior pole of the capsule posterior capsulotomy 69 This creates a clear central visual axis which improves visual acuity 70 In very thick opacified posterior capsules a manual surgical capsulectomy might be needed In the event of IOL replacement a posterior capsulotomy could allow vitreous to migrate into the anterior chamber through the opening previously occluded by the IOL and would have to be removed Posterior capsule opacification has an incidence of about 0 3 to 28 4 2 Retinal detachment normally occurs at a prevalence of 1 in 1 000 0 1 however people who have had cataract surgery are at an increased risk 0 5 0 6 of developing rhegmatogenous retinal detachment RRD the most common form of the condition 71 Cataract surgery increases the rate of vitreous humour liquefaction which leads to increased rates of RRD 72 When a retinal tear occurs vitreous liquid enters the space between the retina and retinal pigment epithelium RPE and presents as flashes of light photopsia dark floaters and loss of peripheral vision 71 Toxic anterior segment syndrome TASS a non infectious inflammatory condition may also occur following cataract surgery it is usually treated with topical corticosteroids in high dosage and frequency 73 Endophthalmitis is a serious infection of intraocular tissues usually following intraocular surgery complications or penetrating trauma and one of the most severe It rarely occurs as a complication of cataract surgery due to the use of prophylactic antibiotics but there is some concern that the clear cornea incision might predispose to the increase of endophthalmitis although no conclusive study has corroborated this suspicion 74 An intracameral injection of antibiotics may be used as a preventive measure A meta analysis showed the incidence of endophthalmitis after phacoemulsification to be 0 092 The risk gets higher in association with factors such as diabetes advanced age larger incision procedures 29 and vitreous communication with the anterior chamber caused by posterior capsule rupture The risk of vitreous infection is at least six times higher than for the aqueous 75 Endophthalmitis typically presents within two weeks after the procedure with manifestations such as decreased visual acuity red eye and pain Hypopyon occurs about 80 of the time Common infective agents include coagulase negative staphylococci and Staphylococcus aureus in about 80 of infections Management includes vitreous humour tap and injection of broad spectrum antibiotics Outcomes can be severe even with treatment and may range from permanently decreased visual acuity to the complete loss of light perception depending on the microbiological etiology 2 Glaucoma may occur and may be very difficult to control It is usually associated with inflammation especially when fragments of the nucleus enter the vitreous cavity Some experts recommend early intervention by posterior pars plana vitrectomy when this condition occurs In most cases raised post operative intraocular pressure is transient and benign usually returning to baseline within 24 hours without intervention Glaucoma patients may experience further visual field loss or a loss of fixation and are more likely to experience intraocular pressure spikes 76 On the other hand secondary glaucoma is an important complication of surgery for congenital cataracts patients can develop this condition even several years after undergoing cataract surgery so they need lifelong surveillance 77 Mechanical pupillary block manifests when the anterior chamber gets shallower as a result of the obstruction of the aqueous humour flow through the pupil by the vitreous face or IOL 78 This is caused by contact between the edge of the pupil and an adjacent structure which blocks the flow of aqueous through the pupil itself The iris then bulges forward and closes the angle between the iris and cornea blocking drainage through the trabecular meshwork and causing an increase in intraocular pressure Mechanical pupillary block has mainly been identified as a complication of anterior chamber intraocular lens implantation but has been known to occur occasionally after posterior IOL implantation 79 Occasionally a peripheral iridectomy may be made to minimize the risk of pupillary block glaucoma 7 Surgical iridectomy can be done manually or with a Nd YAG laser Laser peripheral iridotomy may be done either before or following cataract surgery 80 Swelling of the macula the central part of the retina results in macular oedema and can occur a few days or weeks after surgery Most such cases can be successfully treated Preventative use of nonsteroidal anti inflammatory drugs has been reported to reduce the risk of macular oedema to some extent 81 Uveitis glaucoma hyphema syndrome is a complication caused by the mechanical irritation of a mis positioned IOL over the iris ciliary body or iridocorneal angle 82 Other possible complications include elevated intraocular pressure 78 swelling or oedema of the cornea which is sometimes associated with transient or permanent cloudy vision pseudophakic bullous keratopathy displacement or dislocation of the IOL implant unplanned high refractive error either myopic or hypermetropic due to errors in the ultrasonic biometry measurement of the eye length and calculation of the required intraocular lens power cyanopsia which often occurs for a few days weeks or months after removal of a cataract and floaters which commonly appear after surgery 40 It may be necessary to exchange Note 11 remove Note 12 or reposition Note 13 an IOL after surgery for any of the following reasons 78 Capsular block syndrome which consists in the hyper distention of the lens capsular bag due to the IOL blocking fluid from draining through the anterior capsulotomy This may cause a myopic refractive error 78 Chronic anterior uveitis which is a persistent inflammation of the anterior segment 78 Chronic loss of endothelial cells faster than the rate due to normal aging 78 Iris pigment epithelium loss 78 Physical pain 78 Progressive elongation of the pupil in direction of the IOL s long axis 78 Progressive closing of the anterior chamber angle due to propagation of anterior synechiae without apparent anterior uveitis 78 Incorrect IOL refractive power 78 Incorrect positioning of the IOL including decentring tilt or rotation which partially prevents its correct function 78 Damage or deformation of the IOL 78 Unexpected optical results due to defects of the IOL 78 Undesirable optical phenomena reported by the patient due to any other cause 78 Risk edit Statistically cataract surgery and IOL implantation have the safest and highest success rates of any eye care related procedures 7 As with any type of surgery however some level of risk remains As of 2011 cataract surgery is the most frequently performed surgical procedure in the United States with 1 8 million Medicare beneficiaries undergoing the procedure in 2004 This rate is expected to increase as the population ages 83 Most complications of cataract surgery do not result in long term visual impairment but some severe complications can lead to irreversible blindness 83 A survey of adverse results affecting Medicare patients recorded between 2004 and 2006 showed an average rate of 0 5 for one or more severe post operative complications with the rate decreasing by about 20 over the study period The most important risk factors identified were diabetic retinopathy and a combination of cataract surgery with another intraocular procedure on the same day In the study 97 of the surgeries were not combined with other intraocular procedures the remaining 3 were combined with retinal corneal or glaucoma surgery on the same day 83 Recovery and rehabilitation edit nbsp A shield or patch may be needed for a few days mainly to protect from physical impact and contaminationFollowing cataract surgery side effects such as grittiness watering blurred vision double vision and a red or bloodshot eye may occur although they usually clear after a few days Full recovery from the operation can take four to six weeks 84 Patients are usually advised to avoid getting water in the eye during the first week after surgery and to avoid swimming for two to three weeks as a conservative approach to minimise risk of bacterial infection 7 Most people can return to normal activities the day after phacoemulsification surgery 85 Depending on the procedure they should avoid driving for at least 24 hours after the surgery largely due to effects from the anaesthesia possible swelling affecting focus and pupil dilation causing excessive glare At the first post operative check the surgeon will usually assess whether the patient s vision is suitable for driving 85 With small incision self sealing wounds used with phacoemulsification some of the post operative restrictions common with intracapsular and extracapsular procedures are not relevant Restrictions against lifting and bending were intended to reduce the risk of the wound opening because straining increases intraocular pressure With a self sealing tunnel incision however higher pressure closes the wound more tightly Routine use of a shield is not usually required because inadvertent finger pressure on the eye should not open a correctly structured incision which should only open to point pressure 7 After surgery patients need to prevent contamination by avoiding rubbing their eyes as well as not using eye makeup face cream or lotions Any kind of contact with excessive dust wind pollen or dirt should also be avoided Moreover people are advised to wear sunglasses on bright days since the eyes become more sensitive to bright light for a prolonged period after surgery 86 Topical anti inflammatory drugs and antibiotics are commonly used in the form of eyedrops to reduce the risk of inflammation and infection A shield or eye patch may be prescribed to protect the eye while sleeping The eye will be checked to ensure the IOL remains in place and once it has fully stabilized after about six weeks vision tests will be used to check whether prescription lenses are needed 2 84 In cases where the focal length of the IOL is optimised for distance vision reading glasses are generally needed for near focus 87 In some cases people are dissatisfied with the optical correction provided by the initial implants making removal and replacement necessary this can occur with more complex IOL designs as the patient s expectations might not match with the compromises inherent in these designs or they might not be able to accommodate the difference in distance and near focusing of monovision lenses 33 The patient should not participate in contact or extreme sports or similar activities until cleared to do so by the eye surgeon 88 Outcomes editSee also Visual acuity After full recovery visual acuity depends on the underlying condition of the eye the choice of IOL and any long term complications associated with the surgery More than 90 of operations are successful in restoring useful vision with a low complication rate 89 The World Health Organization WHO recommends at least 80 of eyes should have a presenting visual acuity of 6 6 to 6 18 20 20 to 20 60 after surgery which is considered a good enough visual outcome the percentage is expected to reach at least 90 with best correction Acuity of between 6 18 and 6 60 20 60 to 20 200 is regarded as borderline whereas a value worse than 6 60 20 200 is considered poor Borderline or poor visual outcomes are usually influenced by pre surgery conditions such as glaucoma macular disease and diabetic retinopathy 90 Refractive results using power calculation formulae based on pre operative biometrics leave people within 0 5 dioptres of target correlates to visual acuity of 6 7 5 20 25 when targeted for distance in 55 of cases and within one dioptre correlates to 6 12 20 40 when targeted for distance in 85 of cases Developments in intra operative wavefront technology have demonstrated power calculations that provide improved outcomes yielding 80 of patients within 0 5 dioptres 6 7 5 20 25 or better 37 A ten year prospective survey on refractive outcomes from a UK National Health Service NHS cataract surgery service from 2006 to 2016 showed a mean difference between the targeted and outcome refraction of 0 07 dioptres with a standard deviation of 0 67 and a mean absolute error of 0 50 dioptres 88 76 were within one diopter of target refraction and 62 36 within 0 50 dioptres 91 According to a 2009 study conducted in Sweden factors that affected predicted refraction error included sex pre operative visual acuity and glaucoma together with other eye conditions Second eye surgery macular degeneration age and diabetes did not affect the predicted outcome Prediction error decreased with time which is likely due to the use of improved equipment and techniques including more accurate biometry 92 A 2013 American survey involving nearly two million bilateral cataract surgery patients found immediate sequential bilateral cataract surgery was statistically associated with worse visual outcomes than for delayed sequential bilateral cataract surgery however the difference was small and might not be clinically relevant 93 There is a tendency for post operative refraction to vary slightly over several years A small overall myopic shift has been recorded in 33 6 and a small hypermetropic shift in 45 2 of eyes with the remaining 21 2 in the study having no reported change Most of the change occurred during the first year after surgery 94 Phacoemulsification via a coaxial incision Note 14 may be associated with less astigmatism than the average for bimanual incisions Note 15 but the difference was found to be small and the evidence statistically uncertain 95 96 History edit nbsp A cataract surgery Dictionnaire Universel de Medecine 1746 1748 Main article History of cataract surgery Cataract surgery has a long history in Europe Asia and Africa It is one of the most common and successful surgical procedures in worldwide use due to improvements in techniques for cataract removal and developments in intraocular lens replacement technology in implantation techniques and in IOL design construction and selection 97 Surgical techniques that have contributed to this success include microsurgery viscoelastics phacoemulsification and self sealing incisions 98 Couching was the original form of cataract surgery and was used from antiquity It is still occasionally found in traditional medicine in parts of Africa and Asia In 1753 Samuel Sharp performed the first recorded surgical removal of the entire lens and lens capsule equivalent to intracapsular cataract extraction The lens was removed from the eye through a limbal incision 97 In 1884 Karl Koller became the first surgeon to apply a cocaine solution to the cornea as a local anaesthetic in 1884 99 100 By the beginning of the 20th century the standard surgical procedure was intracapsular cataract extraction ICCE 7 In 1949 Harold Ridley introduced the concept of implantation of the intraocular lens IOL which made visual rehabilitation after cataract surgery a more efficient effective and comfortable process 97 Intracapsular cryoextraction was the favoured form of cataract extraction from the late 1960s to the early 1980s using a liquid nitrogen cooled probe tip to freeze the encapsulated lens to the probe 17 15 101 In 1967 Charles Kelman introduced phacoemulsification which uses ultrasonic energy to emulsify the nucleus of the crystalline lens and remove cataracts by aspiration without a large incision This method of surgery reduced the need for an extended hospital stay and made out patient surgery the standard 102 Ophthalmic viscosurgical devices OVDs which were introduced in 1972 facilitate the procedure and improve overall safety particularly of phacoemulsification by maintaining the shape of the eye at reduced pressure and protecting the internal tissues of the eye without interfering with the operation 97 In the early 1980s Daniele Aron Rosa and colleagues introduced the neodymium doped yttrium aluminum garnet laser Nd YAG laser for posterior capsulotomy 7 In 1985 Thomas Mazzocco developed and implanted the first foldable IOL and Graham Barrett and associates pioneered the use of silicone acrylic and hydrogel foldable lenses 7 In 1987 M Blumenthal and J Moisseiev described the use of a reduced incision size for ECCE They used a 6 5 to 7 mm 0 26 to 0 28 in straight scleral tunnel incision 2 mm 0 079 in behind the limbus with two side ports and an anterior chamber maintainer 59 In 1989 M McFarland introduced a self sealing incision architecture and in 1990 S L Pallin described a chevron shaped incision that minimized the risk of induced astigmatism 59 In 2009 Praputsorn Kosakarn described a method for manual fragmentation of the lens called double nylon loop which consists in splitting the lens into three pieces for extraction allowing a smaller sutureless incision of 4 0 to 5 0 mm 0 16 to 0 20 in and requires implantation of a foldable IOL This technique uses less expensive instruments than phacoemeulsification and is suitable for use in developing countries 59 Regional practice and statistics editUnited Kingdom edit In the UK the practice of NHS healthcare providers referring people with cataracts to surgery widely varied as of 2017 many of the providers were only referring patients with moderate or severe vision loss often with delays 103 This practise occurred despite guidance issued by the NHS Executive in 2000 which urged providers to standardize care streamline the process and increase the number of cataract surgeries performed in order to meet the needs of the aging population 104 In 2019 the national ophthalmology outcomes audit found five NHS trusts had complication rates of between 1 5 and 2 1 however since the first national cataract audit held in 2010 there had been a 38 reduction in posterior capsule rupture complications 105 Asia edit South Asia has the highest global age standardized prevalence of moderate to severe visual impairment 17 5 and mild visual impairment 12 2 The estimated distribution of ophthalmologists ranges from more than 114 per million of population in Japan to none in Micronesia Cataract has traditionally been a major cause of blindness in less developed countries in the region and in spite of improvements to the volume and quality of cataract surgeries the success rate CSR remains low for some of these nations 106 China edit Cataracts are common in China as of 2022 their estimated overall prevalence in Chinese people over 50 years old was 27 45 The environment was an influential factor with the prevalence being 28 79 in rural areas and 26 66 in urban areas Prevalence of cataract considerably varies by age group as well for ages 50 59 it is 7 88 for ages 60 69 it is 24 94 for ages 70 79 it is 51 74 in people over 80 years old it is 78 43 The overall cataract surgery coverage rate was 9 19 The prevalence of cataract and cataract surgical coverage also significantly varies by region 107 India edit Main article Eye care in India India s cataract surgical rate rose from just over 700 operations per million people per year in 1981 to 6 000 per million per year in 2011 thus getting increasingly closer to the estimated requirement of 8 000 8 700 operations per million per year needed to eliminate cataract blindness in the country The rate s rise was partly linked to factors such as increased efficiency due to improved surgical techniques application of day case surgery improvements in operating theatre design and efficient teamwork with sufficient staff 108 In India the pool of people applying for cataract surgery has been widened through social marketing methods aimed to raise awareness about the condition and access to effective surgical treatments The non governmental organization NGO sector and Indian ophthalmologists have developed methods to deal with several problems affecting local communities including outreach camps to find those needing surgery counsellors to explain the system locally manufactured equipment and consumables and a tiered pricing structure using subsidies where appropriate 108 There have been occasional incidents in which several patients have been infected and developed endophthalmitis on the same day at some hospitals associated with eye camps in India Journalists have reported blame being placed on the surgeons the hospital administration and other persons but have not reported on those responsible for sterilizing the surgical instruments and operating theatres involved whether all infections involved the same micro organisms the same theatres or the same staff One investigation found bacteria known to be associated with endophthalmia in the theatre and in the eyes of affected patients and it was claimed the hospital had not followed the required protocol for infection control but the investigation was ongoing and no findings were reported Several instances of surgeons performing more operations per day than officially allowed have been reported but the effects upon sterility of equipment or plausible infection pathways have not been explained 109 In 2022 digital news portal Scroll in contacted the Ministry of Health and Family Welfare requesting official data on the number of patients who had contracted infections following surgery according to their researches since 2006 469 people had either been blinded in one eye or had their vision seriously affected after undergoing surgery at eye camps Further inquiries found at least 519 patients were involved but the total number of surgeries for that period was not mentioned 109 As of 2017 India is claimed to be performing about 6 5 million cataract surgeries per year more than the US Europe and China together 110 Africa edit nbsp Cataract surgery in Bedele EthiopiaCataracts are the main cause of blindness in Africa and affect approximately half of the estimated seven million blind people on the continent a number that is expected to increase with population growth by about 600 000 people per year As of 2005 the estimated cataract surgery rate was about 500 operations per million people per year Progress on gathering information on epidemiology distribution and impact of cataracts within the African continent has been made but significant problems and barriers limiting further access to reliable data remain 111 These barriers relate to awareness acceptance and cost some studies also reported community and family dynamics as discouraging factors Most of the studies held locally reported that cataract surgical rate was lower in females The higher cataract surgery coverage found in some settings in South Africa Libya and Kenya suggest many barriers to surgery can be overcome 112 According to the International Agency for the Prevention of Blindness some sub Saharan African countries have about one ophthalmologist per million people while the National Center for Biotechnology Information stated the percentage of adults above the age of 50 in western sub Saharan Africa who have developed cataract induced blindness is about 6 the highest rate in the world 113 A mathematical model using survey data from sub Saharan Africa showed the incidence of cataracts varies significantly across the continent with the required rate of surgery to maintain a visual acuity level of 6 18 20 60 ranging from about 1 200 to about 4 500 surgeries per year per million people depending on the area Such variations may relate to genetic or cultural differences as well as life expectancy 114 Nigeria edit In 2011 0 78 of the population of Nigeria were blind more than 43 of these developed the condition from cataracts whereas another 9 was a result of aphakia and complications from couching performed by itinerant practitioners Although there are about 2 8 ophthalmologists per million population in Nigeria the cataract surgery rate is only 300 operations per million per year compared with the WHO recommendation of 3 000 per million per year Reasons cited for this situation include inadequate blindness prevention programs shortage of funding and lack of government led investments in training and services Teaching hospitals do not have enough patient surgical load to support training 115 South Africa edit In South Africa facilities vary from government hospitals where subsidised operations for the disadvantaged may be charged at rates that cover the consumables to private clinics in which up to date equipment is used and patients are charged at premium rates Waiting times in government hospitals may be up to two years whereas they are much shorter at private clinics Some hospitals use a system in which two patients are operated upon for cataracts in the theatre at the same time increasing the efficiency of facilities 116 Some charitable organisations in the country provide pro bono cataract surgery in rural areas by using mobile clinics 117 118 As of 2023 the cataract surgery rate in South Africa is less than half of the estimated requirement of at least 2 000 per million population per year needed to eliminate cataract blindness 119 120 In 2011 Lecuona and Cook identified an inadequate level of human resources in the public sector to provide care for the indigent population 120 The main barrier to increasing South Africa s rate of cataract surgery is inadequate surgery capacity a higher annual rate of cataract surgeries by individual surgeons would improve cost effectiveness and personal skills and also contribute towards an overall reduction of risk 120 Latin America edit nbsp Cataract operation in Sao Paulo BrazilA four year longitudinal study of 19 Latin American countries published in 2010 showed most of the countries had increased their surgery rates over that period with increases of up to 186 but still failed to provide adequate surgical coverage The study also shown a significant correlation between gross national income per capita and cataract surgery rate in the countries involved 121 In a study published in 2014 the weighted mean regional surgery rate was found to have increased by 70 from 2005 to 2012 rising from 1 562 to 2 672 cataract surgeries per million inhabitants The weighted mean number of ophthalmologists per million inhabitants in the region was approximately 62 Cataract surgery coverage widely varied across Latin America ranging from 15 in El Salvador to 77 in Uruguay Barriers cited included cost of surgery and lack of awareness about available surgical treatment The number of available ophthalmologists appeared to be adequate but the number of those who practised eye surgery was unknown 122 A 2009 study showed that the prevalence of cataract blindness in people 50 years and older ranged from 0 5 in Buenos Aires to 2 3 in parts of Guatemala Poor vision due to cataracts ranged from 0 9 in Buenos Aires to 10 7 in parts of Peru Cataract surgical coverage ranged from good in parts of Brazil to poor in Paraguay Peru and Guatemala Visual outcome after cataract surgery was close to conformity with WHO guidelines in Buenos Aires where more than 80 of post surgery eyes had visual acuity of 6 18 20 60 or better but ranged between 60 and 79 in most of the other regions and was less than 60 in Guatemala and Peru 123 Social and economic relevance editThe cost of cataract surgery depends on the type of procedure whether it is provided privately or by a government hospital whether it is provided by out patient day care or in patient surgery and on the economic status of people in the region Because of the high cost of the equipment phacoemulsification is generally more expensive than ECCE and MSICS 6 Visual outcomes are variable they depend upon the underlying condition of the eyes and the surgical techniques and lens implants used Regional variations exist due to quality and availability of care The restoration of functional vision or improvement in vision possible in most cases has a large social and economic impact patients may be able to return to paid work or continue their previous jobs and may not become dependent on support from their family or the wider society Studies show a sustained improvement to quality of life financial situation physical well being and mental health Cataract surgery is one of the most cost effective health interventions since its economic benefits considerably exceed the cost of treatment 124 125 The 1998 World Health Report estimated 19 34 million people were bilaterally blind due to age related cataracts and that cataracts were responsible for 43 of all cases of blindness This number and proportion were expected to increase due to population growth and increased life expectancy approximately doubling the number of people older than 60 years The global increase in blindness from cataract is estimated to be at least five million per year a figure of 1 000 new cases per million population per year is used for planning purposes The average outcomes of cataract surgery are improving and consequently surgery is being indicated at an earlier stage in cataract progression increasing the number of operable cases To reduce the backlog of patients it is necessary to operate on more people per year than the new cases alone 126 As of 1998 the rate of surgeries in economically developed countries was about 4 000 to 6 000 per million population per year which was sufficient to meet demand India raised the cataract surgery rate CSR to over 3 000 but this was not considered to be sufficient to reduce the backlog Middle income countries of Latin America and Asia have CSRs of between 500 and 2 000 per million per year whereas China most of Africa and poor countries of Asia had rates of less than 500 In India and South East Asia the rate required to keep up with the increase is at least 3 000 per million population per year in Africa and other parts of the world with smaller percentages of older people a rate of 2 000 may be sufficient in the short term 126 Vision 2020 The Right to Sight a global initiative of the International Agency for the Prevention of Blindness IAPB was intended to reduce or eliminate the main causes of avoidable blindness worldwide by 2020 Programs instituted under Vision 2020 facilitated the planning development and implementation of sustainable national eye care programs including technical support and advocacy 127 The IAPB and WHO launched the program on 18 February 1999 128 129 The Vision 2020 initiative succeeded in bringing avoidable blindness to the global health agenda The causes have not been eliminated but there have been significant changes to their distribution which have been attributed to global demographic shifts Remaining challenges to management of avoidable blindness include population size gender disparities in access to eye care and the availability of a professional workforce 129 It has been estimated there were 43 3 million blind people in 2020 and 295 million with moderate and severe visual impairment MSVI 55 of whom were female The age standardised global prevalence in blindness decreased by 28 5 between 1990 and 2020 but the age standardised prevalence of MSVI increased by 2 5 Cataract remained the global leading cause of blindness in 2020 129 Special populations editCongenital cataracts edit Main article Congenital cataract nbsp Bilateral cataracts in an infant due to congenital rubella syndromeCongenital cataracts involve a condition of lens opacity that is present at birth and occur in a broad range of severity some lens opacities do not progress and are visually insignificant while others can produce profound visual impairment Congenital cataracts may be unilateral or bilateral They can be classified by morphology presumed or defined genetic cause presence of specific metabolic disorders or associated ocular anomalies or systemic findings 3 In general there is greater urgency to remove dense cataracts from very young children because of the risk of amblyopia For optimal visual development in newborns and young infants a visually significant unilateral congenital cataract should be detected and removed before the child is six weeks old while visually significant bilateral congenital cataracts should be removed before 10 weeks 3 Congenital cataracts that are too small to affect vision will not be removed or treated but may be monitored by an ophthalmologist throughout the patient s life Commonly a patient with small congenital cataracts that do not damage vision will be affected later in life though this will take decades to occur 130 As of 2015 update the standard of care for pediatric cataract surgery for children older than two years is primary posterior intraocular lens IOL implantation Primary IOL implantation before the age of seven months is considered to have no advantages over aphakia 131 According to a 2015 study primary IOL implantation in the seven months to two years age groups should be considered in children who require cataract surgery 131 Research into the possibility of regeneration of infant lenses from lens epithelial cells showed interesting results in a small trial study reported in 2016 132 133 Developing world edit The capital equipment for phacoemulsification is expensive and requires expert maintenance and the consumables are also expensive Quality of outcomes is not sufficiently better than those for manual small incision cataract surgery MSICS to justify the difference in cost in a developing world environment 6 Higher risk for operations on separate occasions edit Most patients have bilateral cataracts although surgery in one eye can restore functional vision second eye surgery has many advantages so most patients undergo surgery in each eye on separate days Operating on both eyes on the same day as separate procedures is known as immediately sequential bilateral cataract surgery this can decrease the number of hospital visits thus reducing risk of contagion in an epidemic Immediately sequential bilateral cataract surgery also has significant cost savings and faster visual rehabilitation and neuroadaptation Note 16 Another indication is significant cataracts in both eyes of patients for whom two rounds of anaesthesia and surgery would be unsuitable The risk of simultaneous bilateral complications is low 134 135 Other animals editCataract surgery in small animals such as dogs and cats is a routine ophthalmic procedure with a success rate of around 90 and is usually better for eyes with relatively recent cataract development The presence of other ocular problems may reduce the success rate Procedures are similar to those for humans General anesthesia is likely to be used 136 but sub Tenons and a low dose neuromuscular blockade protocol have also been used used for canine cataract surgery 137 See also edit nbsp Medicine portal nbsp Media related to Cataract surgery at Wikimedia Commons Africa Cataract Project Eye surgery Surgery performed on the eye or its adnexa Himalayan Cataract Project U S nonprofit organization IOLVIP Intraocular lens system to compensate for macular degeneration Ophthalmology Field of medicine treating eye disorders Phakic intraocular lens implantation in series with the natural lens to correct vision in cases of high refractive errors 138 Refractive lens exchange or clear lens extraction Effectively use of the same procedures to replace an IOL with high refractive error when other methods are not effective Notes edit Ciliary sulcus The space between the anterior surface of the ciliary body and the posterior surface of the base of the iris just in front of the position of the natural lens Posterior capsule rupture Unintended tearing of the posterior membrane of the lens capsule which can allow migration of the vitreous into the anterior chamber White to white WTW measurement of an eye is the horizontal diameter of the cornea measured across the corneal limbus Intraoperative aberrometry A tool to take aphakic and pseudophakic refractive measurements during surgery to help optimise IOL power selection and placement Bridle suture A suture passing through the superior rectus muscle of the eye used to rotate the eyeball downwards in eye surgery Hydroexpression Method of removing the lens from the capsule and anterior chamber by carrying it out in a flow of saline solution Viscoexpression Method of removing the lens from the capsule and anterior chamber by carrying it out in a flow of viscoelastic material Zonular dehiscence Breaking of the fibrous strands zonules connecting the crystalline lens to the ciliary body Dropped nucleus A cataract nucleus which has fallen through into the vitreous chamber Nanophthalmic Exceptionally small eyes Exchange The IOL is replaced with another of the same model Remove The IOL is removed and replaced with a different model lens or no replacement lens is implanted Reposition The IOL is surgically moved to another location or rotated Coaxial phacoemulsification uses a single probe to irrrigate emulsify and aspirate which is operated through a single incision Bimanual phacoemulsification uses one probe to emulsify and aspirate and a second that is only used for irrigation Neuroadaptation Changes in the brain which accommodate the presence of a new substance or condition such as the admission of more blue light after removal of a yellow tinted cataract or the inability to adjust the focus of an IOL by the ciliary muscles References edit Cataracts www nei nih gov National Eye Institute Archived from the original on 2 May 2019 Retrieved 27 July 2020 a b c d e f g h i j k l m n o p q r s t u v Moshirfar Majid Milner Dallin Patel Bhupendra C June 21 2022 Cataract Surgery www ncbi nlm nih gov National Center for Biotechnology Information PMID 32644679 Archived from the original on 24 February 2023 Retrieved 8 February 2023 a b c Basic and clinical science course 2011 2012 Pediatric ophthalmology and Strabismus American Academy of Ophthalmology ISBN 978 1615251131 a b c d e f g h i Facts About Cataract September 2009 Archived from the original on 24 May 2015 Retrieved 24 May 2015 Cataract surgery Mayo Foundation for Medical Education and Research MFMER Archived from the original on 19 July 2021 Retrieved 19 July 2021 a b c d e Haldipurkar S S Shikari Hasanain T Gokhale Vishwanath 2009 Wound construction in manual small incision cataract surgery Indian Journal of Ophthalmology 57 1 9 13 doi 10 4103 0301 4738 44491 ISSN 0301 4738 PMC 2661512 PMID 19075401 a b c d e f g h i j k l m n o p q r s t u v w x y Cionni Robert J Snyder Michael E Osher Robert H 2006 6 Cataract surgery In Tasman William ed Duane s Ophthalmology Vol 6 Lippincott Williams amp Wilkins Archived from the original on 20 February 2023 Retrieved 16 February 2023 via www oculist net a b c d e f Gurnani B Kaur K 6 December 2022 Manual Small Incision Cataract Surgery StatPearls Internet Treasure Island FL StatPearls Publishing PMID 35881728 Archived from the original on 1 February 2023 Retrieved 2 March 2023 a b Moshirfar M Milner D Patel B C January 2023 Cataract Surgery Treasure Island FL StatPearls Publishing PMID 32644679 Archived from the original on 2023 02 24 Retrieved 2023 02 08 Pandey S K 2005 Pediatric cataract surgery techniques complications and management Philadelphia Lippincott Williams amp Wilkins p 20 ISBN 978 0781743075 Archived from the original on 2015 05 24 a b Priority eye diseases Archived from the original on 24 May 2015 Retrieved 24 May 2015 Lamoureux E L Fenwick E Pesudovs K Tan D January 2011 The impact of cataract surgery on quality of life Current Opinion in Ophthalmology 22 1 19 27 doi 10 1097 icu 0b013e3283414284 PMID 21088580 S2CID 22760161 Rao G N Khanna R Payal A January 2011 The global burden of cataract Current Opinion in Ophthalmology 22 1 4 9 doi 10 1097 icu 0b013e3283414fc8 PMID 21107260 S2CID 205670997 a b c d e f g h Agarwal Ashvin March 2019 When and How to Convert to ECCE Extracapsular cataract extraction remains a useful plan B crstoday com Archived from the original on 2 March 2023 Retrieved 2 March 2023 a b Toczolowski J July 1993 Thirty years of cryoophthalmology Ann Ophthalmol 25 7 254 6 PMID 8363292 Kim Y J Ha S J 2013 Intracapsular Lens Extraction for the Treatment of Pupillary Block Glaucoma Associated with Anterior Subluxation of the Crystalline Lens Case Rep Ophthalmol 4 3 257 264 doi 10 1159 000356530 PMC 3861857 PMID 24348413 a b Haripriya A Sonawane H Thulasiraj R D 2017 Changing techniques in cataract surgery how have patients benefited Community Eye Health 30 100 80 81 PMC 5820631 PMID 29483751 Boughton Barbara April 2009 Phaco and ECCE EyeNet Magazine American Academy of Ophthalmology Retrieved 5 December 2023 Lawrence D Fedorowicz Z van Zuuren E J et al Cochrane Eyes and Vision Group November 2015 Day care versus in patient surgery for age related cataract The Cochrane Database of Systematic Reviews 2015 11 CD004242 doi 10 1002 14651858 CD004242 pub5 PMC 7197209 PMID 26524611 Liaska A Papaconstantinou D Georgalis I Koutsandrea C Theodosiadis P Chatzistefanou K July 2014 Phaco trabeculectomy in controlled advanced open angle glaucoma and cataract Parallel randomized clinical study of efficacy and safety Semin Ophthalmol 29 4 226 35 doi 10 3109 08820538 2014 880491 PMID 24654699 S2CID 19497442 Akman A Yilmaz G Oto S Akova YA September 2004 Comparison of various pupil dilatation methods for phacoemulsification in eyes with a small pupil secondary to pseudoexfoliation Ophthalmology 111 9 1693 8 doi 10 1016 j ophtha 2004 02 008 PMID 15350324 Rishi P Sharma T Rishi E Chaudhary S P January April 2009 Combined scleral buckling and phacoemulsification Oman J Ophthalmol 2 1 15 8 doi 10 4103 0974 620X 48416 PMC 3018099 PMID 21234218 Charters Linda 15 June 2006 Anticipation is key to managing intra operative floppy iris syndrome Ophthalmology Times Archived from the original on 22 October 2006 Retrieved 2 April 2007 Keay L Lindsley K Tielsch J Katz J Schein O January 2019 Routine preoperative medical testing for cataract surgery The Cochrane Database of Systematic Reviews 1 1 CD007293 doi 10 1002 14651858 CD007293 pub4 PMC 6353242 PMID 30616299 Yorston D 2001 Intraocular Lens IOL Implants in Children Community Eye Health 14 40 57 8 PMC 1705947 PMID 17491933 Lambert S R Aakalu V K Hutchinson A K Pineles S L Galvin J A Heidary G Binenbaum G VanderVeen D K October 2019 Intraocular Lens Implantation during Early Childhood A Report by the American Academy of Ophthalmology Ophthalmology 126 10 1454 1461 doi 10 1016 j ophtha 2019 05 009 PMID 31230794 S2CID 195327519 Archived from the original on 2023 02 27 Retrieved 2023 02 27 a b c d e Who is NOT a Candidate for Cataract Surgery www pacificvision org Retrieved 5 December 2023 a b c d Gogate P Wood M March 2008 Recognising high risk eyes before cataract surgery Community Eye Health 21 65 12 14 PMC 2377383 PMID 18504470 a b c Sridhar U Tripathy K 22 August 2022 Monofocal Intraocular Lenses StatPearls Internet Treasure Island FL StatPearls Publishing PMID 35593809 Archived from the original on 10 July 2022 Retrieved 8 February 2023 a b Mehta R Aref A A November 2019 Intraocular Lens Implantation In The Ciliary Sulcus Challenges And Risks Clin Ophthalmol 27 13 2317 2323 doi 10 2147 OPTH S205148 PMC 6885568 PMID 31819356 a b Goldsberry Dennis H May 2012 Achieving Better Outcomes Using Free Online Post LASIK IOL Calculators crstodayeurope com CRSTEurope Archived from the original on 11 February 2023 Retrieved 11 February 2023 Singh Vivek Mahendrapratap Ramappa Muralidhar Murthy Somasheila Rostov Audrey Talley January 2022 Toric intraocular lenses Expanding indications and preoperative and surgical considerations to improve outcomes Indian J Ophthalmol 70 1 10 23 doi 10 4103 ijo IJO 1785 21 PMC 8917572 PMID 34937203 a b Grayson Douglas 4 October 2011 The Ins and Outs of Lens Explantation Review of Ophthalmology Archived from the original on 14 February 2023 Retrieved 14 February 2023 Salerno Liberdade C Tiveron Jr Mauro C Alio Jorge L 2017 Multifocal intraocular lenses Types outcomes complications and how to solve them Taiwan Journal of Ophthalmology 7 4 179 184 doi 10 4103 tjo tjo 19 17 PMC 5747227 PMID 29296549 MacRae Scott Crystalens The First Accommodating Intraocular Lens Implant www urmc rochester edu University of Rochester Flaum Eye Institute Archived from the original on 14 February 2023 Retrieved 14 February 2023 Ramappa Muralidhar Singh Vivek Mahendrapratap Murthy SomasheilaI Rostov AudreyTalley 2022 Toric intraocular lenses Expanding indications and preoperative and surgical considerations to improve outcomes Indian Journal of Ophthalmology 70 1 10 23 doi 10 4103 ijo IJO 1785 21 ISSN 0301 4738 PMC 8917572 PMID 34937203 a b Roach Linda September 2013 Intraoperative Wavefront Aberrometry Wave of the Future EyeNet Magazine American Academy of Ophthalmology Archived from the original on 26 February 2023 Retrieved 26 February 2023 Roach Linda November December 2010 How to Choose an Aspheric Intraocular Lens EyeNet Magazine American Academy of Ophthalmology Archived from the original on 17 February 2023 Retrieved 17 February 2023 Downie L E Busija L Keller P R et al Cochrane Eyes and Vision Group May 2018 Blue light filtering intraocular lenses IOLs for protecting macular health The Cochrane Database of Systematic Reviews 2018 5 CD011977 doi 10 1002 14651858 CD011977 pub2 PMC 6494477 PMID 29786830 a b Hayashi K Hayashi H 2006 Visual function in patients with yellow tinted intraocular lenses compared with vision in patients with non tinted intraocular lenses British Journal of Ophthalmology 90 8 1019 1023 doi 10 1136 bjo 2006 090712 PMC 1857188 PMID 16597662 FDA Approves RxSight s Light Adjustable Lens First IOL To Enable Refractive Correction After Cataract Surgery innovation ucsf edu University of California San Francisco 27 November 2017 Archived from the original on 21 February 2023 Retrieved 21 February 2023 Jain Sneha Patel Alpa S Tripathy Koushik DelMonte Derek W Baartman Brandon 3 October 2022 DelMonte Derek W ed Light Adjustable Intraocular lenses EyeWiki American Academy of Ophthalmology Archived from the original on 16 February 2023 Retrieved 16 February 2023 Portelinha Joana Ferreira Tiago Luis do Carmo Bravo Reddy Vandana Shafer Brian 8 January 2023 Shafer Brian ed Special Cases Secondary Piggy Back Lenses Eyewiki American Academy of Ophthalmology Archived from the original on 20 February 2023 Retrieved 20 February 2023 Hasan Sumaiya Tripathy K 22 August 2022 Phakic Intraocular Lens Myopia StatPearls Internet Treasure Island FL StatPearls Publishing PMID 32809598 Archived from the original on 20 December 2022 Retrieved 21 February 2023 Vicchrilli Sue Glasser David B McNett Cherie Burke Mara Pearse Repka Michael X October 2018 Premium IOLs A Legal and Ethical Guide to Billing Medicare Beneficiaries EyeNet Magazine Archived from the original on 21 February 2023 Retrieved 21 February 2023 a b c d Minakaran N Ezra D G Allan B D July 2020 Topical anaesthesia plus intracameral lidocaine versus topical anaesthesia alone for phacoemulsification cataract surgery in adults The Cochrane Database of Systematic Reviews 2020 7 CD005276 doi 10 1002 14651858 cd005276 pub4 PMC 8190979 PMID 35658539 a b c Gurnani Bharat Kaur Kirandeep 6 December 2022 Phacoemulsification StatPearls Internet Treasure Island FL StatPearls Publishing PMID 35015444 Archived from the original on 30 January 2023 Retrieved 20 February 2023 Wier L M Steiner C A Owens P L February 2015 Surgeries in Hospital Owned Outpatient Facilities 2012 HCUP Statistical Brief 188 Rockville MD Agency for Healthcare Research and Quality Archived from the original on 2021 05 14 Retrieved 2015 04 06 Cataract surgery Mayo Foundation for Medical Education and Research MFMER Archived from the original on 19 July 2021 Retrieved 19 July 2021 Alio J L Abdou A A Puente A A Zato M A Nagy Z June 2014 Femtosecond laser cataract surgery updates on technologies and outcomes Journal of Refractive Surgery 30 6 420 427 doi 10 3928 1081597x 20140516 01 PMID 24972409 Popovic M Campos Moller X Schlenker M B Ahmed I I October 2016 Efficacy and Safety of Femtosecond Laser Assisted Cataract Surgery Compared with Manual Cataract Surgery A Meta Analysis of 14 567 Eyes Ophthalmology 123 10 2113 2126 doi 10 1016 j ophtha 2016 07 005 PMID 27538796 Devgan Uday 15 August 2017 Three rules for corneal phaco incisions www healio com Retrieved 12 December 2023 a b Scholtz Sibylle January 2007 History of Ophthalmic Viscosurgical Devices crstodayeurope com Cataract amp Refractive Surgery Today Europe Archived from the original on 13 February 2023 Retrieved 13 February 2023 Mohammadpour M Erfanian R Karimi N January 2012 Capsulorhexis Pearls and pitfalls Saudi J Ophthalmol 26 1 33 40 doi 10 1016 j sjopt 2011 10 007 PMC 3729482 PMID 23960966 Yanoff Myron Duker Jay S 1 January 2009 Ophthalmology Elsevier Health Sciences ISBN 978 0323043328 Archived from the original on 19 February 2023 Retrieved 19 February 2023 via Google Books Faust KJ Winter 1984 Hydrodissection of soft nuclei J Am Intraocul Implant Soc 10 1 75 7 doi 10 1016 s0146 2776 84 80088 9 PMID 6706823 Patel Alpa S DelMonte Derek W Mohan Hridya Christenbury Joseph 24 September 2022 Christenbury Joseph ed Hydro Manoeuvres in Cataract Surgery Eyewiki American Academy of Ophthalmology Archived from the original on 20 February 2023 Retrieved 20 February 2023 Mathey Christoph F Kohnen Thomas B Ensikat Hans Jurgen Koch Hans Reinhard January 1994 Polishing methods for the lens capsule Histology and scanning electron microscopy Journal of Cataract amp Refractive Surgery 20 1 64 69 doi 10 1016 S0886 3350 13 80046 6 PMID 8133483 S2CID 11738948 a b c d e f Singh K Misbah A Saluja P Singh A K December 2017 Review of manual small incision cataract surgery Indian J Ophthalmol 65 12 1281 1288 doi 10 4103 ijo IJO 863 17 PMC 5742955 PMID 29208807 Devgan Uday 27 January 2019 Use of an AC maintainer in Cataract Surgery cataractcoach com Archived from the original on 1 March 2023 Retrieved 1 March 2023 Oetting Thomas Capsulorhexis using a cystotome needle during cataract surgery Archived from the original on 26 August 2008 Retrieved 28 May 2008 Thim K Krag S Corydon L March 1993 Hydroexpression and viscoexpression of the nucleus through a continuous circular capsulorhexis J Cataract Refract Surg 19 2 209 12 doi 10 1016 s0886 3350 13 80944 3 PMID 8487162 S2CID 35741983 Archived from the original on 2023 03 01 Retrieved 2023 03 01 Varshney S Jhala L S November 2022 Hydroexpression A novel technique to deliver nucleus in small incision cataract surgery Indian J Ophthalmol 70 11 4066 doi 10 4103 ijo IJO 1594 22 PMC 907245 PMID 36308162 Mohan S John B Rajan M Malkani H Nagalekshmi S V Singh S June 2017 Glued intraocular lens implantation for eyes with inadequate capsular support Analysis of the postoperative visual outcome Indian J Ophthalmol 65 6 472 476 doi 10 4103 ijo IJO 375 16 PMC 5508457 PMID 28643711 a b Wang Robert C Fuller Dwain G Hutton William S 2006 66 Retained Lens Material In Tasman William ed Duane s Ophthalmology Vol 6 Lippincott Williams amp Wilkins Archived from the original on 19 February 2023 Retrieved 16 February 2023 via www oculist net Vajpayee R B Sharma N Dada T Gupta V Kumar A Dada V K 1 June 2001 Management of posterior capsule tears Surv Ophthalmol 45 6 473 88 doi 10 1016 s0039 6257 01 00195 3 PMID 11425354 Chaturvedi Vivek Sabherwal Ryan Kim Leo A Pittner Andrew Bhagat Neelakshi Lim Jennifer I Mukkamala Lekha Patel Nimesh 23 June 2022 Patel Nimesh ed Suprachoroidal Hemorrhage Eyewiki American Academy of Ophthalmology Archived from the original on 13 December 2022 Retrieved 22 February 2023 Hilford D Hilford M Mathew A Polkinghorne P J 2009 Posterior vitreous detachment following cataract surgery Eye 23 6 1388 1392 doi 10 1038 eye 2008 273 PMID 18776863 Videos YAG Laser Capsulotomy Pacific Cataract and Laser Institute Archived from the original on 2 April 2019 Retrieved 2 April 2019 Karahan Eyyup Er Duygu Kaynak Suleyman Summer 2014 An Overview of Nd YAG Laser Capsulotomy Medical Hypothesis Discovery amp Innovation in Ophthalmology Journal 3 2 45 50 PMC 4346677 PMID 25738159 a b Steel D March 2014 Retinal detachment BMJ Clinical Evidence 2014 PMC 3940167 PMID 24807890 Feltgen N Walter P January 2014 Rhegmatogenous retinal detachment an ophthalmologic emergency Deutsches Arzteblatt International 111 1 2 12 21 quiz 22 doi 10 3238 arztebl 2014 0012 PMC 3948016 PMID 24565273 Toxic Anterior Segment Syndrome After Cataract Surgery Centers for Disease Control and Prevention 29 June 2007 Archived from the original on 13 March 2013 Retrieved 18 April 2013 Endophthalmitis Lecturio Archived from the original on 19 July 2021 Retrieved 19 July 2021 Bennett John E 8 August 2019 Endophthalmitis Mandell Douglas and Bennett s Principles and Practice of Infectious Diseases 9th ed Elsevier Health Sciences ISBN 9780323550277 Gokhale Parag A Patterson Emory May June 2007 Elevated IOP After Cataract Surgery Glaucoma today Bryn Mawr Communications LLC Archived from the original on 2023 02 25 Retrieved 2023 02 25 Swamy B N Billson F Martin F Donaldson C Hing S Jamieson R Grigg J Smith J E December 2007 Secondary glaucoma after paediatric cataract surgery Br J Ophthalmol 91 12 1627 30 doi 10 1136 bjo 2007 117887 PMC 2095522 PMID 17475699 a b c d e f g h i j k l m n o Masket Samuel Rorer Eva Stark Walter Holladay Jack T MacRae Scott Tarver Michelle E Glasser Adrian Calogero Don Hilmantel Gene Nguyen Tieuvi Eydelman Malvina January 2017 Special Report The American Academy of Ophthalmology Task Force Consensus Statement on Adverse Events with Intraocular Lenses Ophthalmology 124 1 142 144 doi 10 1016 j ophtha 2016 09 031 PMID 27726961 Archived from the original on 2023 04 17 Retrieved 2023 02 27 Gaton D D Mimouni K Lusky M Ehrlich R Weinberger D September 2003 Pupillary block following posterior chamber intraocular lens implantation in adults Br J Ophthalmol 87 9 1109 11 doi 10 1136 bjo 87 9 1109 PMC 1771845 PMID 12928277 Ou Yvonne 5 July 2021 Side Effects of Laser Iridotomy www brightfocus org University of California San Francisco Archived from the original on 23 February 2023 Retrieved 23 February 2023 Lim B X Lim C H Lim D K Evans J R Bunce C Wormald R November 2016 Prophylactic non steroidal anti inflammatory drugs for the prevention of macular oedema after cataract surgery The Cochrane Database of Systematic Reviews 2016 11 CD006683 doi 10 1002 14651858 CD006683 pub3 PMC 6464900 PMID 27801522 Zemba M Camburu G 2017 Uveitis Glaucoma Hyphaema Syndrome General review Romanian Journal of Ophthalmology 61 1 11 17 doi 10 22336 rjo 2017 3 PMC 5710046 PMID 29450365 a b c Stein Joshua D Grossman Daniel S Mundy Kevin M Sugar Alan Sloan Frank A 2 June 2011 Severe Adverse Events after Cataract Surgery Among Medicare Beneficiaries Ophthalmology 118 9 1716 1723 doi 10 1016 j ophtha 2011 02 024 PMC 3328508 PMID 21640382 Archived from the original on 7 April 2022 Retrieved 14 February 2023 a b Recovery Cataract surgery www nhs uk 15 January 2018 Archived from the original on 12 February 2019 Retrieved 12 February 2023 a b How Many Days Rest Are Needed After Cataract Surgery southcaleye com 18 May 2022 Archived from the original on 9 December 2022 Retrieved 22 February 2023 Dudek Lara 15 September 2020 After Cataract Surgery Dos and Don ts Archived from the original on 26 February 2023 Retrieved 22 February 2023 Sridhar U Tripathy K January 2023 Monofocal Intraocular Lenses Treasure Island FL StatPearls Publishing Porter Daniel 1 August 2022 When to Resume Exercise After an Eye Surgery or Injury www aao org American Academy of Ophthalmology Archived from the original on 28 February 2023 Retrieved 28 February 2023 Wong Tien Yin 5 May 2001 Effect of increasing age on cataract surgery outcomes in very elderly patients BMJ 322 7294 1104 6 doi 10 1136 bmj 322 7294 1104 PMC 1120237 PMID 11337443 Hashmi Farzeen Khalid Khan Qazi Assad Chaudhry Tanveer Anjum Ahmad Khabir 2013 Visual Outcome of Cataract Surgery PDF Journal of the College of Physicians and Surgeons Pakistan 23 6 448 449 PMID 23763813 Brogan K Diaper C J Rotchford A P 2019 Cataract surgery refractive outcomes representative standards in a National Health Service setting British Journal of Ophthalmology 103 4 539 543 doi 10 1136 bjophthalmol 2018 312209 PMID 29907629 S2CID 49219217 Kugelberg Maria Lundstrom Mats May 2009 Refractive Outcome After Cataract Surgery Cataract Surgery CRST Global Europe Edition Archived from the original on 2023 04 17 Retrieved 2023 03 03 Owen Julia P Blazes Marian Lacy Megan Yanagihara Ryan T Van Gelder Russell N Lee Aaron Y Lee Cecilia S 2021 Refractive Outcomes After Immediate Sequential vs Delayed Sequential Bilateral Cataract Surgery JAMA Ophthalmol 139 8 876 885 doi 10 1001 jamaophthalmol 2021 2032 PMC 8251655 PMID 34196667 Archived from the original on 2022 10 24 Retrieved 2023 03 03 Lee Natalie Si Yi Ong Keith May 2023 Changes in refraction after cataract phacoemulsification surgery Int Ophthalmol 43 5 1545 1551 doi 10 1007 s10792 022 02550 9 PMC 10149444 PMID 36223001 Jin Chongfei Chen Xinyi Law Andrew Kang Yunhee Wang Xue Xu Wen Yao Ke 20 September 2017 Different sized incisions for phacoemulsification in age related cataract Cochrane Database of Systematic Reviews Cochrane Database Syst Rev 9 9 CD010510 CD010510 doi 10 1002 14651858 CD010510 pub2 PMC 5665700 PMID 28931202 Rose Aron D April 2006 Bimanual Versus Coaxial crstoday com Cataract and Refractive Surgery Today Retrieved 21 August 2023 a b c d Davis G January February 2016 The Evolution of Cataract Surgery Mo Med Missouri State Medical Association 113 1 58 62 PMC 6139750 PMID 27039493 Chapter 5 Microsurgery and Extracapsular Cataract Extraction PDF rajswasthya nic in pp 36 44 Archived PDF from the original on 6 May 2021 Retrieved 12 February 2023 Goerig M Bacon D van Zundert A May June 2012 Carl Koller cocaine and local anesthesia some less known and forgotten facts Regional Anesthesia and Pain Medicine 37 3 318 24 doi 10 1097 AAP 0b013e31825051f3 PMID 22531385 S2CID 205432874 Altman A J Albert D M Fournier G A January February 1985 Cocaine s use in ophthalmology our 100 year heritage Survey of Ophthalmology 29 4 300 6 doi 10 1016 0039 6257 85 90154 7 PMID 3885453 Meadow Norman B 15 October 2005 Cryotherapy A fall from grace but not a crash Ophthalmology Times Pandey Suresh K Milverton E John Maloof Anthony J October 2004 A tribute to Charles David Kelman MD ophthalmologist inventor and pioneer of phacoemulsification surgery Clinical amp Experimental Ophthalmology 32 5 529 533 doi 10 1111 j 1442 9071 2004 00887 x ISSN 1442 6404 PMID 15498067 S2CID 25230092 Two thirds of eye units restricting access to cataract surgery OnMedica 10 November 2017 Archived from the original on 10 November 2017 Retrieved 28 December 2017 Action on Cataracts Good Practice Guidance PDF NHS Executive via the Royal College of Ophthalmologists January 2000 Archived PDF from the original on 2017 12 30 Retrieved 2017 12 29 referenced in Context Guideline for Cataracts in adults NICE October 2017 Archived from the original on 2017 12 30 Retrieved 2017 12 29 Revealed The trusts with the highest cataract complication rates Health Service Journal 11 October 2019 Archived from the original on 11 October 2019 Retrieved 21 November 2019 Yusufu Mayinuer Bukhari Javaria Yu Xiaobin Lin Timothy P H Lam Dennis S C Wang Ningli September October 2021 Challenges in Eye Care in the Asia Pacific Region Asia Pacific Journal of Ophthalmology 10 5 423 429 doi 10 1097 APO 0000000000000391 PMID 34516436 S2CID 237505240 Du Y F Liu H R Zhang Y Bai W L Li R Y Sun R Z Wang N L 18 January 2022 Prevalence of cataract and cataract surgery in urban and rural Chinese populations over 50 years old a systematic review and Meta analysis Int J Ophthalmol 15 1 141 149 doi 10 18240 ijo 2022 01 21 PMC 8720354 PMID 35047369 a b Vs Murthy G Jain B Shamanna B Subramanyam D 2014 Improving cataract services in the Indian context Community Eye Health 27 85 4 5 PMC 4069775 PMID 24966453 a b Barnagarwala Tabassum 23 February 2022 When India s mass eye camps leave people blind Scroll in Archived from the original on 23 February 2023 Retrieved 23 February 2023 Mabiyan Rashmi 25 October 2017 Cataract prevalent in India despite largest number of surgeries Dr Mahipal S Sachdev Centre for Sight Archived from the original on 23 February 2023 Retrieved 23 February 2023 Wong T Y October 2005 Cataract surgery programmes in Africa The British Journal of Ophthalmology 89 10 1231 1232 doi 10 1136 bjo 2005 072645 PMC 1772878 PMID 16170103 Aboobaker S Courtright P January March 2016 Barriers to Cataract Surgery in Africa A Systematic Review Middle East Afr J Ophthalmol 23 1 145 9 doi 10 4103 0974 9233 164615 PMC 4759895 PMID 26957856 The Epidemic of Cataracts in sub Saharan Africa PDF www embracerelief org Report Archived PDF from the original on 14 March 2023 Retrieved 24 February 2023 Lewallen S Courtright P Etya ale D Mathenge W Schmidt E Oye J Clark A Williams T October 2013 Cataract incidence in sub Saharan Africa what does mathematical modeling tell us about geographic variations and surgical needs Ophthalmic Epidemiol 20 5 260 6 doi 10 3109 09286586 2013 823215 PMID 24070099 S2CID 32828934 Babalola O E December 2011 The peculiar challenges of blindness prevention in Nigeria a review article Afr J Med Med Sci 40 4 309 19 PMID 22783680 Speedy Eye Surgery for Cataract Patients www westerncape gov za Department of Health and Wellness Western Cape Government 20 July 2016 Archived from the original on 25 February 2023 Retrieved 25 February 2023 Supporting cataract surgery backlog for Mandela Day 2023 www lifehealthcare co za 18 July 2023 Archived from the original on 13 August 2023 Retrieved 13 August 2023 The gift of sight Mediclinic The Future of Healthcare 29 Oct 2019 Archived from the original on 27 June 2022 Retrieved 13 August 2023 Pretoria Eye Institute gives 70 patients the gift of sight www eyeinstitute co za Archived from the original on 25 February 2023 Retrieved 25 February 2023 a b c Lecuona K Cook C 2011 South Africa s cataract surgery rates why are we not meeting our targets PDF South African Medical Journal 101 8 510 512 PMID 21920119 Archived PDF from the original on 2023 02 26 Retrieved 2023 02 26 Lansingh Van C Resnikoff Serge Tingley Kelley Kimberly Nano Maria E Martens Marion Silva Juan C Duerksen Rainald Carter Marissa J 19 March 2010 Cataract Surgery Rates in Latin America A Four Year Longitudinal Study of 19 Countries Ophthalmic Epidemiology 17 2 75 81 doi 10 3109 09286581003624962 PMID 20302429 S2CID 38013312 Archived from the original on 4 March 2023 Retrieved 4 March 2023 Batlle Juan Francisco Lansingh Van Charles Silva Juan Carlos Eckert Kristen Allison Resnikoff Serge 2014 The Cataract Situation in Latin America Barriers to Cataract Surgery American Journal of Ophthalmology 158 2 242 250 doi 10 1016 j ajo 2014 04 019 ISSN 0002 9394 PMID 24792101 Limburg H Silva J C Foster A 2009 Cataract in Latin America findings from nine recent surveys PDF Report Vol 25 Rev Panam Salud Publica pp 449 55 Archived PDF from the original on 2021 09 09 Retrieved 2023 03 04 Social and Economic Impacts of Restoring Sight www hollows org The Fred Hollows Foundation 7 April 2017 Archived from the original on 25 March 2023 Retrieved 25 March 2023 Finger R P Kupitz D G Fenwick E Balasubramaniam B Ramani R V Holz F G Gilbert C E August 2012 The impact of successful cataract surgery on quality of life household income and social status in South India PLOS ONE 7 8 e44268 Bibcode 2012PLoSO 744268F doi 10 1371 journal pone 0044268 PMC 3432104 PMID 22952945 a b Foster Allen ed 2000 Vision 2020 the cataract challenge Community Eye Health 13 34 17 19 PMC 1705965 PMID 17491949 Vision 2020 www aao org American Academy of Ophthalmology Archived from the original on 5 March 2023 Retrieved 5 March 2023 VISION 2020 www iapb org International Agency for the Prevention of Blindness Archived from the original on 7 March 2023 Retrieved 5 March 2023 a b c Abdulhussein Dalia Hussein Mina Abdul 30 September 2022 WHO Vision 2020 Have We Done It Ophthalmic Epidemiology 30 4 331 339 doi 10 1080 09286586 2022 2127784 PMID 36178293 S2CID 252621547 Facts About Cataract nei nih gov National Eye Institute Archived from the original on 2017 10 14 Retrieved 2017 10 18 a b Struck M C October 2015 Long term Results of Pediatric Cataract Surgery and Primary Intraocular Lens Implantation From 7 to 22 Months of Life JAMA Ophthalmol 133 10 1180 1183 doi 10 1001 jamaophthalmol 2015 2062 PMID 26111188 Monahan Patrick 9 March 2016 Eyes can regenerate their own lenses after cataract surgery Science Archived from the original on 10 March 2023 Retrieved 10 March 2023 Lin Haotian Ouyang Hong Zhu Jie Huang Shan Liu Zhenzhen Chen Shuyi Cao Guiqun Li Gen Signer Robert A J Xu Yanxin Chung Christopher Zhang Ying Lin Danni Patel Sherrina Wu Frances Cai Huimin Hou Jiayi Wen Cindy Jafari Maryam Liu Xialin Luo Lixia Zhu Jin Qiu Austin Hou Rui Chen Baoxin Chen Jiangna Granet David Heichel Christopher Shang Fu Li Xuri Krawczyk Michal Skowronska Krawczyk Dorota Wang Yujuan Shi William Chen Daniel Zhong Zheng Zhong Sheng Zhang Liangfang Chen Shaochen Morrison Sean J Maas Richard L Zhang Kang Liu Yizhi 9 March 2016 Lens regeneration using endogenous stem cells with gain of visual function Nature 531 7594 323 328 Bibcode 2016Natur 531 323L doi 10 1038 nature17181 PMC 6061995 PMID 26958831 S2CID 4397702 Alio Jorge L Nowrouzi Ali 29 August 2022 Immediately sequential bilateral cataract surgery importance during the COVID 19 pandemic Saudi Journal of Ophthalmology 36 2 124 128 doi 10 4103 sjopt sjopt 131 22 inactive 1 August 2023 PMC 9535909 PMID 36211314 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint DOI inactive as of August 2023 link Obuchowska I Mariak Z 2006 Jednoczesna operacja zacmy w obojgu oczach zalety i wady Simultaneous bilateral cataract surgery advantages and disadvantages Klin Oczna in Polish 108 7 9 353 6 PMID 17290841 Cataract surgery www rvc ac uk London UK Royal Veterinary College Retrieved 11 December 2023 Bayley Kellam D Gates M Carolyn Anastassiadis Zoe Read R A 18 May 2023 The use of sub Tenon s anesthesia versus a low dose neuromuscular blockade for canine cataract surgery A comparative study of 224 eyes Veterinary Ophthalmology doi 10 1111 vop 13111 Barsam Allon Allan Bruce 17 July 2014 Excimer laser refractive surgery versus phakic intraocular lenses for the correction of moderate to high myopia Cochrane Database of Systematic Reviews 6 CD007679 doi 10 1002 14651858 cd007679 pub4 ISSN 1465 1858 PMID 24937100 Further reading editFrampton G Harris P Cooper K Lotery A Shepherd J November 2014 The clinical effectiveness and cost effectiveness of second eye cataract surgery a systematic review and economic evaluation Health Technology Assessment NIHR Journals Library 18 68 1 205 v vi doi 10 3310 hta18680 PMC 4781176 PMID 25405576 18 68 Prajna NV Ravilla TD Srinivasan S 2015 Ch 11 Cataract Surgery In Debas HT Donkor P Gawande A Jamison DT Kruk ME Mock CN eds Essential Surgery Disease Control Priorities Vol 1 3rd ed The International Bank for Reconstruction and Development The World Bank doi 10 1596 978 1 4648 0346 8 hdl 10986 21568 ISBN 978 1 4648 0346 8 PMID 26740991 Archived from the original on 2022 01 19 Retrieved 2017 08 16 Tasman William ed 2006 Duane s Ophthalmology Lippincott Williams amp Wilkins Archived from the original on 2022 11 27 Retrieved 2023 02 19 via www oculist net External links editYoutube video of phacoemulification technique Retrieved from https en wikipedia org w index php title Cataract surgery amp oldid 1189839686 Extracapsular cataract extraction, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.