Meesmann corneal dystrophy
Meesmann corneal dystrophyAn autosomal dominant condition OMIM:122100 characterised by fragility of the anterior corneal epithelium due to the presence of innumerable microcysts. Patients are typically asymptomatic until adulthood when the corneal microcysts rupture, causing erosions and symptoms including photophobia, contact lens intolerance and intermittent diminution of visual acuity. Rarely, subepithelial scarring causes irregular corneal astigmatism and permanent visual impairment.
Disorganised and thickened epithelium with widespread cytoplasmic vacuolation and numerous small, round, debris-laden intraepithelial cysts.
Caused by defects of KRT3, which encodes cornea-specific keratin 3, and KRT12, which encodes cornea-specific keratin 12 (which together form a heterotetrameric complex).