Meesmann corneal dystrophy (MECD) is a rare hereditary autosomal dominant disease that is characterized as a type of corneal dystrophy and a keratin disease. MECD is characterized by the formation of microcysts in the outermost layer of the cornea, known as the anterior corneal epithelium. The anterior corneal epithelium also becomes fragile. This usually affects both eyes rather than a single eye and worsens over time. There are two phenotypes, Meesmann corneal dystrophy 1 (MECD1) and Meesmann corneal dystrophy 2 (MECD2), which affect the genes KRT3 and KRT12, respectively. A heterozygous mutation in either of these genes will lead to a single phenotype.[1][2] Many with Meesmann corneal dystrophy are asymptomatic or experience mild symptoms.[3]
It is named after the German ophthalmologist Alois Meesmann (1888-1969).[4][5] It is often considered as the "Meesmann-Wilke syndrome", after the joint contribution of Meesmann and Wilke in 1939.[4][6] Research was later contributed by Stocker and Holt in 1954 through 1955 who found a variant of Meesmann corneal dystrophy called "Stocker-Holt Dystrophy".[3]
Meesmann corneal dystrophy is a non-inflammatory condition that effects the restricted region of the cornea epithelium which is the outermost layer.[2] Onset of symptoms begin during infancy or early childhood but may not become noticeable or problematic for many years.[3][7][8]
Geneticsedit
It has been associated with genes KRT3 and KRT12 located on chromosome 12 and 17 respectively found through the use of Polymerase chain reaction or PCR.[3][9] These two genes function for keratin production and code for the production of keratin K3 (type II) and K12 (type I).[1][9] There are several methods to find errors or mutations in the KRT3 and KRT12 genes including deletion/duplication analysis, sequence analysis of the entire coding region, and targeted variant analysis. These methods includes molecular genetic tests which include Next-Generation (NGS)/Massively parallel sequencing (MPS) and bi-directional sanger sequence analysis.[10]
A heterozygous missense mutation of Leu132Pro in the KRT12 gene exhibits a more severe phenotype while a mutation of Arg135Thr, which is most commonly found, exhibits milder symptoms.[11] The Leu132Pro mutation and the animo acid change of N133K occurs in the helix-initiation motif of the keratin and was found to cause significant structural changes to the KRT12 gene.[9][12] This mutation also leads to the aggregation of keratine and alters the keratin configuration of the corneal epithelium.[2] The mechanism by which this mutation in K12 causes the formation of microcysts remains poorly understood.[2]
Diagnosisedit
Patients with Meesmann corneal dystrophy may remain asymptomatic or experience mild symptoms. Symptoms of Meesmann corneal dystrophy often go unnoticed and is usually found and diagnosed during routine eye examinations.[13] This slowly progressive disorder is characterized by microcysts that are filled with debris in the epithelium of the cornea detected and clinically diagnosed with slit-lamp biomicroscopy and retroillumination.[1][9] Under electron microscopy, there are an abnormal aggregation of keratin filament bundles in the center of the cornea.[12] It was found to not affect the corneal stromal layer or endothelial cell layer.[14] Signs of this disease appear in the early first few years of life and begin as eye irritation. Under magnification, corneal changes consisting of punctate opacities in the epithelium are found. Occasionally, these are found in the Bowman membrane. Patients diagnosed with Meesmann corneal dystrophy are unable to tolerate the use of contact lenses which irritate the corneal epithelium. Light microscopy and electron microscopy found that the basement membrane is thickened with an intracytoplasmic substance. Under slit-lamp photography, the cornea was found to be uneven due to the damage and scarring from the thickening basement membrane and anterior stroma. The buildup of foreign materials may cause vision blurriness or cloudiness.[6]
Treatmentedit
Patients with Meesman corneal dystrophy will develop chronic eye dryness that can be treated with lubricating eye drops but most cases do not require further treatment.[1] In severe cases, surgery may be required due to excessive corneal scarring such as superficial keratectomy (SK), phototherapeutic keratectomy (PTK), lamellar keratoplasty, or penetrating keratoplasty.[1] Patients may relapse in symptoms but surgery prolongs the reoccurrence and may also lessen severity.[1] Currently there are researchers studying the use of allele-specific siRNA against mutants with single-nucleotide specificity as a potential method of treatment for MECD.[11]
^A. Meesmann. Klinische und anatomische Untersuchungen über eine bisher unbekannte, dominant vererbte Dystrophia epithelialis corneae. Bericht der Deutschen ophthalmologischen Gesellschaft, Heidelberg, 1938, 52: 154-158.
^ abA. Meesmann, F. Wilke. Klinische und anatomische Untersuchungen über eine bisher unbekannte, dominant vererbte Epithel Dystrophie der Horn haut. Klinische Monatsblätter für Augenheilkunde, Stuttgart, 1939, 103: 361-391.
^Reference, Genetics Home. "Meesmann corneal dystrophy". Genetics Home Reference. Retrieved 2020-05-01.
^ abcdHassan, H; Thaung, C; Ebenezer, N D; Larkin, G; Hardcastle, A J; Tuft, S J (2012-12-07). "Severe Meesmann's epithelial corneal dystrophy phenotype due to a missense mutation in the helix-initiation motif of keratin 12". Eye. 27 (3): 367–373. doi:10.1038/eye.2012.261. ISSN 0950-222X. PMC3597869. PMID 23222558.
^"Meesmann Corneal Dystrophy (MCD) via the KRT12 Gene - Tests - GTR - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2020-05-01.
^ abLiao, Haihui; Irvine, Alan D.; MacEwen, Caroline J.; Weed, Kathryn H.; Porter, Louise; Corden, Laura D.; Gibson, A. Bethany; Moore, Jonathan E.; Smith, Frances J. D.; McLean, W. H. Irwin; Moore, C. B. Tara (2011-12-12). "Development of Allele-Specific Therapeutic siRNA in Meesmann Epithelial Corneal Dystrophy". PLOS ONE. 6 (12): e28582. Bibcode:2011PLoSO...628582L. doi:10.1371/journal.pone.0028582. ISSN 1932-6203. PMC3236202. PMID 22174841.
^ abIrvine, A D Coleman, C M Moore, J E Swensson, O Morgan, S J McCarthy, J H Smith, F J D Black, G C M McLean, W H I. A novel mutation in KRT12 associated with Meesmann's epithelial corneal dystrophy. Copyright 2002 British Journal of Ophthalmology. OCLC 680207259.{{cite book}}: CS1 maint: multiple names: authors list (link)
^Cremona, Federico A; Ghosheh, Faris R; Laibson, Peter R; Rapuano, Christopher J; Cohen, Elisabeth J (April 2008). "Meesmann Corneal Dystrophy Associated With Epithelial Basement Membrane and Posterior Polymorphous Corneal Dystrophies". Cornea. 27 (3): 374–377. doi:10.1097/ico.0b013e31815c18fa. ISSN 0277-3740. PMID 18362674. S2CID 22769981.
^Nishino, Tsubasa; Kobayashi, Akira; Mori, Natsuko; Masaki, Toshinori; Yokogawa, Hideaki; Fujiki, Keiko; Yanagawa, Ai; Murakami, Akira; Sugiyama, Kazuhisa (2018-12-07). "In vivo histology and p.L132V mutation in KRT12 gene in Japanese patients with Meesmann corneal dystrophy". Japanese Journal of Ophthalmology. 63 (1): 46–55. doi:10.1007/s10384-018-00643-6. ISSN 0021-5155. PMID 30535821. S2CID 54448751.
External linksedit
December 15, 2023
meesmann, corneal, dystrophy, mecd, rare, hereditary, autosomal, dominant, disease, that, characterized, type, corneal, dystrophy, keratin, disease, mecd, characterized, formation, microcysts, outermost, layer, cornea, known, anterior, corneal, epithelium, ant. Meesmann corneal dystrophy MECD is a rare hereditary autosomal dominant disease that is characterized as a type of corneal dystrophy and a keratin disease MECD is characterized by the formation of microcysts in the outermost layer of the cornea known as the anterior corneal epithelium The anterior corneal epithelium also becomes fragile This usually affects both eyes rather than a single eye and worsens over time There are two phenotypes Meesmann corneal dystrophy 1 MECD1 and Meesmann corneal dystrophy 2 MECD2 which affect the genes KRT3 and KRT12 respectively A heterozygous mutation in either of these genes will lead to a single phenotype 1 2 Many with Meesmann corneal dystrophy are asymptomatic or experience mild symptoms 3 Meesmann Corneal DystrophyOther namesMeesmann Epithelial Corneal Dystrophy Meesmann Wilke SyndromeMultiple opaque spots in the corneal epitheliumSpecialtyOphthalmologySymptomsAnterior corneal intraepithelial microcysts Corneal erosions Photophobia Lacrimation Intermittent visual acuity loss rarely seriously impaired Nonprogressive corneal dystrophy Fine punctate corneal opacities Episodic foreign body sensation Increased tear production eye stinging BlepharospasmUsual onsetInfancy or Young ChildhoodDurationLifelongTypesMeesmann corneal dystrophy 1 Meesmann corneal dystrophy 2Diagnostic methodSlit Lamp BiomicroscopyTreatmentEye drops Corneal Surgery Autosomal Dominant Inheritance PatternIt is named after the German ophthalmologist Alois Meesmann 1888 1969 4 5 It is often considered as the Meesmann Wilke syndrome after the joint contribution of Meesmann and Wilke in 1939 4 6 Research was later contributed by Stocker and Holt in 1954 through 1955 who found a variant of Meesmann corneal dystrophy called Stocker Holt Dystrophy 3 Contents 1 Symptoms and signs 2 Genetics 3 Diagnosis 4 Treatment 5 See also 6 References 7 External linksSymptoms and signs editAnterior corneal intraepithelial microcysts Corneal erosions Photophobia Lacrimation Intermittent visual acuity loss rarely seriously impaired Nonprogressive corneal dystrophy Fine punctate corneal opacities Episodic foreign body sensation Increased tear production Eye stinging BlepharospasmMeesmann corneal dystrophy is a non inflammatory condition that effects the restricted region of the cornea epithelium which is the outermost layer 2 Onset of symptoms begin during infancy or early childhood but may not become noticeable or problematic for many years 3 7 8 Genetics editIt has been associated with genes KRT3 and KRT12 located on chromosome 12 and 17 respectively found through the use of Polymerase chain reaction or PCR 3 9 These two genes function for keratin production and code for the production of keratin K3 type II and K12 type I 1 9 There are several methods to find errors or mutations in the KRT3 and KRT12 genes including deletion duplication analysis sequence analysis of the entire coding region and targeted variant analysis These methods includes molecular genetic tests which include Next Generation NGS Massively parallel sequencing MPS and bi directional sanger sequence analysis 10 A heterozygous missense mutation of Leu132Pro in the KRT12 gene exhibits a more severe phenotype while a mutation of Arg135Thr which is most commonly found exhibits milder symptoms 11 The Leu132Pro mutation and the animo acid change of N133K occurs in the helix initiation motif of the keratin and was found to cause significant structural changes to the KRT12 gene 9 12 This mutation also leads to the aggregation of keratine and alters the keratin configuration of the corneal epithelium 2 The mechanism by which this mutation in K12 causes the formation of microcysts remains poorly understood 2 Diagnosis editPatients with Meesmann corneal dystrophy may remain asymptomatic or experience mild symptoms Symptoms of Meesmann corneal dystrophy often go unnoticed and is usually found and diagnosed during routine eye examinations 13 This slowly progressive disorder is characterized by microcysts that are filled with debris in the epithelium of the cornea detected and clinically diagnosed with slit lamp biomicroscopy and retroillumination 1 9 Under electron microscopy there are an abnormal aggregation of keratin filament bundles in the center of the cornea 12 It was found to not affect the corneal stromal layer or endothelial cell layer 14 Signs of this disease appear in the early first few years of life and begin as eye irritation Under magnification corneal changes consisting of punctate opacities in the epithelium are found Occasionally these are found in the Bowman membrane Patients diagnosed with Meesmann corneal dystrophy are unable to tolerate the use of contact lenses which irritate the corneal epithelium Light microscopy and electron microscopy found that the basement membrane is thickened with an intracytoplasmic substance Under slit lamp photography the cornea was found to be uneven due to the damage and scarring from the thickening basement membrane and anterior stroma The buildup of foreign materials may cause vision blurriness or cloudiness 6 Treatment editPatients with Meesman corneal dystrophy will develop chronic eye dryness that can be treated with lubricating eye drops but most cases do not require further treatment 1 In severe cases surgery may be required due to excessive corneal scarring such as superficial keratectomy SK phototherapeutic keratectomy PTK lamellar keratoplasty or penetrating keratoplasty 1 Patients may relapse in symptoms but surgery prolongs the reoccurrence and may also lessen severity 1 Currently there are researchers studying the use of allele specific siRNA against mutants with single nucleotide specificity as a potential method of treatment for MECD 11 See also editCorneal dystrophy List of cutaneous conditions caused by mutations in keratins Epithelial basement membrane dystrophy Reis Bucklers corneal dystrophy Thiel Behnke corneal dystrophy CataractReferences edit a b c d e f Greiner Jack V Lindsay Michael E Kenyon Kenneth R Herman John P Reddy Chaitanya V December 2017 Meesmann epithelial corneal dystrophy recurrence following photorefractive keratectomy Canadian Journal of Ophthalmology 52 6 e211 e213 doi 10 1016 j jcjo 2017 05 009 ISSN 0008 4182 PMID 29217044 a b c d Allen Edwin H A Courtney David G Atkinson Sarah D Moore Johnny E Mairs Laura Poulsen Ebbe Toftgaard Schiroli Davide Maurizi Eleonora Cole Christian Hickerson Robyn P James John 2016 01 11 Keratin 12 missense mutation induces the unfolded protein response and apoptosis in Meesmann epithelial corneal dystrophy Human Molecular Genetics 25 6 1176 1191 doi 10 1093 hmg ddw001 ISSN 0964 6906 PMC 4764196 PMID 26758872 a b c d Online Mendelian Inheritance in Man OMIM 122100 a b synd 3139 at Who Named It A Meesmann Klinische und anatomische Untersuchungen uber eine bisher unbekannte dominant vererbte Dystrophia epithelialis corneae Bericht der Deutschen ophthalmologischen Gesellschaft Heidelberg 1938 52 154 158 a b A Meesmann F Wilke Klinische und anatomische Untersuchungen uber eine bisher unbekannte dominant vererbte Epithel Dystrophie der Horn haut Klinische Monatsblatter fur Augenheilkunde Stuttgart 1939 103 361 391 Reference Genetics Home Meesmann corneal dystrophy Genetics Home Reference Retrieved 2020 05 01 OMIM Entry 300778 CORNEAL DYSTROPHY LISCH EPITHELIAL LECD omim org Retrieved 2020 05 01 a b c d Hassan H Thaung C Ebenezer N D Larkin G Hardcastle A J Tuft S J 2012 12 07 Severe Meesmann s epithelial corneal dystrophy phenotype due to a missense mutation in the helix initiation motif of keratin 12 Eye 27 3 367 373 doi 10 1038 eye 2012 261 ISSN 0950 222X PMC 3597869 PMID 23222558 Meesmann Corneal Dystrophy MCD via the KRT12 Gene Tests GTR NCBI www ncbi nlm nih gov Retrieved 2020 05 01 a b Liao Haihui Irvine Alan D MacEwen Caroline J Weed Kathryn H Porter Louise Corden Laura D Gibson A Bethany Moore Jonathan E Smith Frances J D McLean W H Irwin Moore C B Tara 2011 12 12 Development of Allele Specific Therapeutic siRNA in Meesmann Epithelial Corneal Dystrophy PLOS ONE 6 12 e28582 Bibcode 2011PLoSO 628582L doi 10 1371 journal pone 0028582 ISSN 1932 6203 PMC 3236202 PMID 22174841 a b Irvine A D Coleman C M Moore J E Swensson O Morgan S J McCarthy J H Smith F J D Black G C M McLean W H I A novel mutation in KRT12 associated with Meesmann s epithelial corneal dystrophy Copyright 2002 British Journal of Ophthalmology OCLC 680207259 a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link Cremona Federico A Ghosheh Faris R Laibson Peter R Rapuano Christopher J Cohen Elisabeth J April 2008 Meesmann Corneal Dystrophy Associated With Epithelial Basement Membrane and Posterior Polymorphous Corneal Dystrophies Cornea 27 3 374 377 doi 10 1097 ico 0b013e31815c18fa ISSN 0277 3740 PMID 18362674 S2CID 22769981 Nishino Tsubasa Kobayashi Akira Mori Natsuko Masaki Toshinori Yokogawa Hideaki Fujiki Keiko Yanagawa Ai Murakami Akira Sugiyama Kazuhisa 2018 12 07 In vivo histology and p L132V mutation in KRT12 gene in Japanese patients with Meesmann corneal dystrophy Japanese Journal of Ophthalmology 63 1 46 55 doi 10 1007 s10384 018 00643 6 ISSN 0021 5155 PMID 30535821 S2CID 54448751 External links edit Retrieved from https en wikipedia org w index php title Meesmann corneal dystrophy amp oldid 1100230994, wikipedia, wiki, book, books, library,
