Effects of diabetes duration and HgA1C level on corneal endothelial morphology

Objective: The aim of this study is to investigate the effects of the HbA1c level and the duration of diabetes mellitus on the corneal endothelium morphology and to compare between healthy individuals and diabetes mellitus patients with non-proliferative diabetic retinopathy and proliferative diabetic retinopathy. Material and methods: Ninety patients who applied to the Health Sciences University Ulucanlar Eye Training and Research Hospital between January 2016 and January 2017 were included in this prospective randomized study. In the study, 45 diabetes mellitus patients and 45 healthy individuals were evaluated. The diabetes patients were compared in terms of HbA1c level, diabetes mellitus duration, corneal endothelial cell density, coefficient of variation, standard deviation, and hexagonality with healthy control group. Results: A statistically significant difference was found in the endothelial cell densitometer, coefficient of variation, and standard deviation measurements between the diabetes mellitus patients and the control (healthy) group. But, there was no statistically significant difference between 6A (hexagonality) and central corneal thickness measurements. There was a negative correlation between HbA1c levels and diabetes mellitus times and endothelial cell densitometer values in the patients with diabetes mellitus diagnosis and standard deviation values in the positive direction. There was a statistically significant difference between diabetes mellitus patients with the diagnosis of non-proliferative diabetic retinopathy and proliferative diabetic retinopathy in the endothelial cell densitometer and standard deviation values. But there was not any statistically significant difference between coefficient of variation, 6A, and central corneal thickness values. Conclusion: The endothelial cell densitometer in diabetes mellitus patients with retinopathy is lower than that in healthy individuals. There is a negative correlation between retinopathy severity and corneal endothelial cell density. Diabetes affects negatively not only vascular tissues but also avascular cornea.