Clinical observations on the corneal thickness and the corneal endothelium in diabetes mellitus.

The corneal thickness was measured by pachometry and the corneal endothelium was photographed by specular microscopy in 81 insulin-dependent juvenile diabetic outpatients. The corneal thickness of a normal group, diabetics without and with proliferative retinopathy was (mean +/- SD): 0.527 +/- 0.028, 0.544 +/- 0.028, and 0.566 +/- 0.027 mm, respectively (2p less than 0.01). As revealed in the specular photomicrographs, minute folds in the endothelial layer were found in 13 of the diabetics versus 1 of the normal group (2p less than 0.01). The cell density and the occurrence of dystrophic changes in the endothelium did not differ from those in normal persons. The augmented corneal thickness in the diabetic subjects is tentatively interpreted as minimal corneal swelling. It seemed to be present very early in the disease and may thus be one of the earliest clinically detectable changes off the diabetic eye.