Meesmann's epithelial dystrophy of the cornea.

Two separate pedigrees had typical Meesmann's dystrophy of the corneal epithelium. Histologic examination of one patient from each pedigree showed two characteristic findings in corneal epithelium; the previously designated "peculiar substance" in the cells, and the vacuolated homogeneous substance mostly within the cysts. The primary disturbance probably involves the cytoplasmic ground substance that ultimately may result in complete homogenization of cells and the formation of cysts. Thickening of the epithelial basement membrane is variable and is a nonspecific response by the epithelial basal cells.