Excessive sensitivity to light with the sensation of discomfort or pain in the eyes due to exposure to bright light.

Replacement of corneal tissue with scar tissue as a result of injury to the deeper layers of the cornea.

The term corneal dystrophy embraces a heterogenous group of bilateral genetically determined non-inflammatory corneal diseases that are restricted to the cornea.

Meesmann corneal dystrophy-1 (MECD1) is a dominantly inherited disorder characterized by the presence of multitudinous microcysts within the anterior epithelium on slit lamp examination. The disorder can cause foreign body sensation and photophobia but is often asymptomatic and detected in the course of routine eye examination. Microcysts are evident even in asymptomatic individuals. Rarely, a more severe phenotype with corneal erosions and scarring can lead to significant loss of visual acuity requiring treatment by keratoplasty or corneal grafting. A subtle feature is the presence of gray serpiginous lines within the anterior epithelium (summary by Liao et al., 2011). Genetic Heterogeneity of Meesmann Corneal Dystrophy MECD2 (618767) is caused by mutation in the KRT3 gene (148043) on chromosome 12q13.