Clinical and genetic update of corneal dystrophies

Exp Eye Res. 2019 Sep;186:107715. doi: 10.1016/j.exer.2019.107715. Epub 2019 Jul 10.

Abstract

The International Committee for Classification of Corneal Dystrophies (IC3D) distinguishes between 22 distinct forms of corneal dystrophy which are predominantly autosomal dominant, although autosomal recessive and X-chromosomal dominant patterns do exist. Before any genetic examination, there should be documentation of a detailed corneal exam of as many affected and unaffected family members as possible, because detailed phenotypic description is essential for accurate diagnosis. Corneal documentation should be performed in direct and indirect illumination at the slit lamp with the pharmacologically dilated pupil. For the majority of the corneal dystrophies, a phenotype-genotype correlation has not been demonstrated. However, for the dystrophies associated with mutations in the transforming growth factor, ß-induced gene (TGFBI) a general phenotype-genotype correlation is evident. The discovery of collagen, type XVII, alpha 1 mutation (COL17A1), causative in the called epithelial recurrent erosion dystrophy (ERED) was a very important step in the accurate diagnosis of corneal dystrophies. This led to the subsequent discovery that the entity previously called 10q Thiel-Behnke corneal dystrophy, was in reality actually COL17A1 ERED, and not Thiel-Behnke corneal dystrophy. In addition to the phenotypic landmarks, we describe the current genotype of the individual corneal dystrophies. Differential diagnosis can be aided by information on histopathology, optical coherence tomography (OCT), and confocal microscopy.

Keywords: cornea; corneal dystrophy; endothelial corneal dystrophy; epithelial corneal dystrophy; genetic eye diseases; hereditary eye diseases; stromal corneal dystrophy.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Collagen Type I / genetics
  • Corneal Dystrophies, Hereditary* / genetics
  • Corneal Dystrophies, Hereditary* / pathology
  • Epithelium, Corneal / pathology
  • Genetic Predisposition to Disease
  • Humans
  • Transforming Growth Factor beta1 / genetics

Substances

  • Collagen Type I
  • TGFB1 protein, human
  • Transforming Growth Factor beta1
  • collagen type I, alpha 1 chain

Supplementary concepts

  • Epithelial Recurrent Erosion Dystrophy