Subepithelial mucinous corneal dystrophy. Clinical and pathological correlations.

We describe a family with an unusual autosomal dominant anterior corneal dystrophy. The onset was characterized by frequent, recurrent corneal erosions in the first decade. This subsided during adolescence and was followed by progressive decreased vision. Slit-lamp examination revealed bilateral subepithelial opacities and haze, involving the entire cornea, but most dense centrally. Histopathological study revealed a subepithelial band of eosinophilic, periodic acid-Schiff-positive, alcian blue-positive, hyaluronidase-sensitive material anterior to Bowman's layer. Electron microscopy demonstrated subepithelial deposition of fine fibrillar material consistent with glycosaminoglycan. Immunohistochemical analysis indicated that the accumulated material contained a combination of chondroitin 4-sulfate and dermatan sulfate. This unique condition clinically resembled Grayson-Wilbrandt dystrophy, but differed histochemically. To our knowledge, this anterior corneal dystrophy has not previously been reported, and it is best described by the name "subepithelial mucinous corneal dystrophy."