We demonstrate a novel approach for the definitive treatment of Lisch epithelial corneal dystrophy via an unintentionally staged alcohol keratectomy and intentionally targeted minor limbal excision with cautery. A 46-year-old woman presented with visually significant corneal changes, suspected to be Lisch epithelial corneal dystrophy after clinical examination, anterior segment optical coherence tomography, and confocal microscopy. Alcohol keratectomy was performed with complete resolution, but there was visually significant recurrence at 2 years. As the abnormal epithelial recurrence originated in a linear tapered pattern from a focal superior limbal region, minor limbal excision with cautery and alcohol keratectomy was performed. Histopathological analysis demonstrated cytoplasmic vacuolation and glycogen granules. The limbal tissue demonstrated normal histological features. The patient's vision returned to baseline on reepithelialization with a clear cornea, with no recurrence in over 5-year follow-up. Our targeted two-staged approach provides definitive treatment for Lisch epithelial corneal dystrophy and highlights the focal limbal origin of abnormal cells.

The International Committee for the Classification of Corneal Dystrophies (IC3D) was created in 2005 to develop a new classification system integrating current information on phenotype, histopathology, and genetic analysis. This update is the third edition of the IC3D nomenclature. Peer-reviewed publications from 2014 to 2023 were evaluated. The new information was used to update the anatomic classification and each of the 22 standardized templates including the level of evidence for being a corneal dystrophy [from category 1 (most evidence) to category 4 (least evidence)]. Epithelial recurrent erosion dystrophies now include epithelial recurrent erosion dystrophy, category 1 ( COL17A1 mutations, chromosome 10). Signs and symptoms are similar to Franceschetti corneal dystrophy, dystrophia Smolandiensis, and dystrophia Helsinglandica, category 4. Lisch epithelial corneal dystrophy, previously reported as X-linked, has been discovered to be autosomal dominant ( MCOLN1 mutations, chromosome 19). Classic lattice corneal dystrophy (LCD) results from TGFBI R124C mutation. The LCD variant group has over 80 dystrophies with non-R124C TGFBI mutations, amyloid deposition, and often similar phenotypes to classic LCD. We propose a new nomenclature for specific LCD pathogenic variants by appending the mutation using 1-letter amino acid abbreviations to LCD. Pre-Descemet corneal dystrophies include category 1, autosomal dominant, punctiform and polychromatic pre-Descemet corneal dystrophy (PPPCD) ( PRDX3 mutations, chromosome 10). Typically asymptomatic, it can be distinguished phenotypically from pre-Descemet corneal dystrophy, category 4. We include a corneal dystrophy management table. The IC3D third edition provides a current summary of corneal dystrophy information. The article is available online at https://corneasociety.org/publications/ic3d .

To report the genetic etiology of Lisch epithelial corneal dystrophy (LECD). Multicenter cohort study. A discovery cohort of 27 individuals with LECD from 17 families, including 7 affected members from the original LECD family, 6 patients from 2 new families and 14 simplex cases, was recruited. A cohort of 6 individuals carrying a pathogenic MCOLN1 (mucolipin 1) variant was reviewed for signs of LECD. Next-generation sequencing or targeted Sanger sequencing were used in all patients to identify pathogenic or likely pathogenic variants and penetrance of variants. Nine rare heterozygous MCOLN1 variants were identified in 23 of 27 affected individuals from 13 families. The truncating nature of 7 variants and functional testing of 1 missense variant indicated that they result in MCOLN1 haploinsufficiency. Importantly, in the homozygous and compound-heterozygous state, 4 of 9 LECD-associated variants cause the rare lysosomal storage disorder mucolipidosis IV (MLIV). Autosomal recessive MLIV is a systemic disease and comprises neurodegeneration as well as corneal opacity of infantile-onset with epithelial autofluorescent lysosomal inclusions. However, the 6 parents of 3 patients with MLIV confirmed to carry pathogenic MCOLN1 variants did not have the LECD phenotype, suggesting MCOLN1 haploinsufficiency may be associated with reduced penetrance and variable expressivity. MCOLN1 haploinsufficiency is the major cause of LECD. Based on the overlapping clinical features of corneal epithelial cells with autofluorescent inclusions reported in both LECD and MLIV, it is concluded that some carriers of MCOLN1 haploinsufficiency-causing variants present with LECD. Corneal dystrophy (CD) is most recently defined as a collection of rare hereditary non-inflammatory disorders of abnormal deposition of substances in the cornea. CD was coined in 1890 by Arthur Groenouw and Hugo Biber, and the efforts of Ernst Fuchs, Wilhelm Uhthoff, and Yoshiharu Yoshida solidified the foundation of the understanding of these diseases. As proposed in 2015 by the International Classification of Corneal Dystrophies (IC3D), CD is sub-classified by the anatomic location affected: epithelial/subepithelial, epithelial-stromal, stromal, and endothelial dystrophies. Discoveries and unique case studies continue to broaden our understanding and classification of these diseases; therefore, it is difficult to categorize every single dystrophy solely into these four major labels.   The objective of this article is to present an overview of the evaluation and management for the most prominent and understood variants of CD. Highlights of these dystrophies will be discussed. However, further in-depth discussion on these dystrophies will be in separate StatPearls articles.  Patients with CD can be asymptomatic, but if symptoms occur, they typically experience bilateral visual acuity loss, typically in the form of irregular astigmatism. Depending on the corneal layer affected, patients may also manifest with photophobia, dry eyes, corneal edema, and recurrent corneal erosions, especially with epithelial-based CD, which causes considerable pain. Symptoms can begin at any age, depending on the diagnosis. Treatment can range from conservative measures to corneal transplantation.   CD is a significant but rare ocular disease. The genetic component of this disease is important for patients to understand, especially for affected patients involved with family planning. As we begin to understand genetics in greater detail, better evaluation and treatments for CD will come to fruition.  The objective of this article is to present an overview of the general evaluation and management for the most prominent and understood variants of CD. Highlights of these dystrophies will be covered, but the author intends to elaborate on these dystrophies separately in other StatPearls articles. The variants of CD based on their new anatomic classifications in IC3D are:  Epithelial and subepithelial dystrophies  : Epithelial basement membrane corneal dystrophy (EBMCD), also previously known as map-finger-dot dystrophy, Cogan microcystic dystrophy, and anterior basement membrane dystrophy. . Epithelial recurrent erosion dystrophies (EREDs) which includes Franceschetti corneal dystrophy, dystrophia smolandiensis, and dystrophia helsinglandica . Subepithelial mucinous corneal dystrophy (SMCD) . Meesmann corneal dystrophy (MECD) also known as juvenile epithelial corneal dystrophy . Lisch epithelial corneal dystrophy (LECD) . Gelatinous drop-like corneal dystrophy (GDLD) . Epithelial-Stromal Dystrophies (still included under epithelial and subepithelial dystrophies) : Lattice corneal dystrophy (LCD), with its subtypes: type I (TGFBI mutation) and type II (familial amyloidosis Finnish type), including LCD variants . Granular corneal dystrophy (GCD), types I and II (Avellino-type)  . Reis-Bückler’s corneal dystrophy (RBCD) . Thiel-Behnke corneal dystrophy (honeycomb dystrophy) (TBCD) . Stromal dystrophies: Macular corneal dystrophy (MCD)  . Schnyder corneal dystrophy (SCD)  . Congenital stromal corneal dystrophy (CSCD)  . Fleck corneal dystrophy (FCD)  . Posterior amorphous corneal dystrophy (PACD)  . Pre-Descemet corneal dystrophy (PDCD)  . Central cloudy dystrophy of francois (CCDF) . Endothelial Corneal Dystrophies: Fuchs endothelial corneal dystrophy (FECD)  . Posterior polymorphous corneal dystrophy (PPCD)  . Congenital hereditary endothelial dystrophy (CHED)  . X-linked endothelial corneal dystrophy (XECD) .