Corneal endothelium in patients with diabetes mellitus: a historical cohort study

Retinopathy is the major cause of ocular morbidity in patients with diabetes mellitus. Chronic hyperglycemia spares no organ and can affect the morphology and function of the various corneal layers, compromising its transparency. This study was conducted to associate the status of corneal endothelium to diabetes mellitus (DM) and identify risk factors of compromised corneal endothelium.

A total of 220 eyes of randomly selected patients (110 diabetic and 110 nondiabetic) were subjected to detailed slitlamp and fundus evaluation. Corneal endothelial status was evaluated using the Nidek Confoscan 2. Cell density, percentage polymegathism, and pleomorphism were calculated. The findings in diabetic patients were compared to those without disease. The outcome was correlated to diabetic retinopathy (DR). The effects of hypertension, hyperlipidemia, age, gender, type, duration, glycemic control, and grades of DR was also considered.

The mean corneal endothelial cell density was -175 cells/mm2 (95% CI -317 to -33 cells/mm2) less in eyes of diabetic patients. The number of endothelial cells with polymegathism was significantly greater among eyes of diabetic patients. There were less corneal endothelial cells with pleomorphism in nondiabetic patients. Polymegathism and pleomorphism of corneal endothelial cells seems to be positively associated with DM type II. Cell density was significantly lower in eyes with DR than those without DR.

Corneal endothelium in diabetic patients seems to be compromised. Evaluation of corneal endothelium should be part of protocol for eye care of diabetic patients.