[Macular, lattice and granular dystrophy of the cornea: ultra-histochemistry and ultrastructure study]

Keratoplasty specimens from 19 patients with macular corneal dystrophy (MCD), 11 patients with lattice corneal dystrophy (LCD) and 2 patients with granular corneal dystrophy (GCD) were examined by combinations of histochemistry, electron microscopy and electron--histochemistry. Electron histochemistry disclosed that the deposits of MCD have sulfate chondroitin and another hyaluronidase--resistant glycoaminoglycan and that the deposits of LCD have a little sulfate chondroitin. The authors suggest: (1) the possible pathologic mechanism of MCD is that the keratocytes and endothelial cells synthesize abnormal fibrillogranular material which consists of glycoaminoglycan, glycoprotein and lipid; (2) LCD is a primary localized corneal amyloidosis in which the amyloid deposits may result from corneal epithelial cells and keratocytes with a little sulfate chondroitin; (3) the deposits synthesized by corneal epithelial cells and keratocytes in GCD may result from a genetic defect in processing or synthesizing proteins.