Central discoid corneal dystrophy.
ABSTRACT To present a small kindred with a unique dominantly inherited corneal stromal dystrophy.
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.
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.
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.