Ocular correlates of inborn metabolic defects.

The eye provides unique opportunities for the detection, during life, of deposits of storage substances and other characteristic changes resulting from inborn metabolic defects. The cornea shows the macromolecular polysaccharides of Hurler's disease, the cystine crystals in cystinosis, and the copper deposits of Wilson's disease. The sclera shows characteristic pigmentation in alcaptonuria. The iris shows the lack of pigmentation in various types of albinism. The lens is cataractous in galactosemia and dislocated in homocystinuria. The vitreous is opacified in familial amyloidosis. The retina shows different and characteristic deposits with the diseases of Tay-Sachs, Niemann-Pick, metachromatic leukodystrophy, and Farber's lipogranulomatosis. The retinal veins show pronounced tortuosity with Fabry's disease. There is some evidence that optic neuropathy occurs in glucose-6-phosphate dehydrogenase deficiency. Curiously, few abnormalities in the eye have been described in subjects with the glycogen storage diseases.