Eye, Granular corneal dystrophy

Corneal dystrophies are a diverse group of hereditary, usually bilateral, slowly progressive disorders characterized by protein deposition in the cornea leading to opacification. Granular corneal dystrophy (GCD) belongs to the category of epithelial-stromal TGFBI dystrophies, a group of dystrophies that involve the corneal epithelium and stroma and are caused by mutations in TGFBI (transforming growth factor beta induced; keratoepithelin). Microscopically, GCD shows the presence of hyaline deposits that may extend from the deep epithelium to Descemet membrane. These hyaline deposits stain red with Masson's trichrome (see Related Content) and are negative for other histochemical stains such as PAS, Alcian blue/Hale’s colloidal iron, and Congo red, which helps to distinguish GCD from other dystrophies. The deposits are immunoreactive for keratoepithelin. Treatment ranges from phototherapeutic keratectomy (laser) to corneal transplantation, with generally good outcomes.