Central discoid corneal dystrophy

Abstract

Purpose: To present a small kindred with a unique dominantly inherited corneal stromal dystrophy.

Methods: A 31-year-old man was noted to have bilateral, symmetric, central discoid corneal stromal opacification. We performed bilateral penetrating keratoplasties for decreased visual acuity, glare, and photophobia.

Results: Light microscopy revealed multiple extracellular vacuoles, concentrated in the anterior one-half of the central corneal stroma. Material within the vacuoles demonstrated intense reactivity with alcian blue and colloidal iron stains, consistent with glycosaminoglycan deposition. Transmission electron microscopy demonstrated nonmembrane-bound vacuoles in the stroma that contained a faintly osmiophilic matrix and black circular profiles. Immunohistochemical analysis of the vacuolar deposits revealed that chondroitin sulfate was the primary glycosaminoglycan present. A clinical and serologic evaluation revealed no evidence of a systemic storage disorder. Genetic analysis did not reveal a mutation in the coding region of the CHST6 gene.

Conclusions: Given these unique clinical and histopathologic findings as well as nearly identical clinical findings in the patient's father and one of four brothers, the authors believe that this represents a previously unreported, dominantly inherited corneal stromal dystrophy.