Structural and functional studies of the corneal endothelium in diabetes mellitus.

We performed specular microscopy, anterior segment ocular fluorophotometry, corneal pachymetry, and tonometry on 14 patients with chronic type I diabetes and nonproliferative retinopathy and on 14 age-matched control subjects. The eyes of patients with diabetes had an increased coefficient of variation of endothelial cell area, a decreased percentage of hexagonal endothelial cells, increased corneal autofluorescence, and increased intraocular pressure, which confirmed previous studies. There was no difference, however, in corneal thickness or endothelial permeability to fluorescein. Thus, we were unable to detect any abnormality in endothelial function in these diabetic corneas in the unstressed state, despite structurally abnormal endothelial cells.