Corneal epithelial basement membrane changes in diabetes.

The corneas of 12 eye donors with maturity-onset diabetes were obtained, and the corneal epithelial basement membranes were studied by transmission electron microscopy. Similar tissue was obtained from 12 nondiabetic eye donors who were matched for age (within 2 years) and race. The mean thickness of the corneal epithelial basement membrane in nondiabetic patients was 0.33 micrometer (+/- 0.11 S.D.), which gives a normal range of 0.11 to 0.55 micrometer. None of the nondiabetic basement membranes lay outside this range. The basement membranes of four of the 12 diabetics exceeded this thickness. No race or sex difference was seen in basement membrane thickness, nor was a clear trend seen with age. Multilaminated basement membranes were seen in eight diabetic patients and six nondiabetic patients. Multilamination was more clearly related to basement membrane thickness than to the presence or absence of diabetes.