Changes in Corneal Endothelial Cells in Patients with Type II Diabetes Mellitus

Abstract

Background: Diabetes mellitus has toxic effects on all cells of the body. Cornea is no exception and structural and morphological alterations have been found in endothelial cells in diabetics.
Purpose: To evaluate and compare central corneal thickness, and endothelial cell count and morphological characteristics between diabetics and non-diabetics and to determine the relation of these parameters with the diabetes duration.
Material and Methods: This hospital based analytical observational study included 65 type II diabetics with good glycaemic control and 65 age-matched non-diabetics as control. The diabetics were further divided on the basis of duration of diabetes into two groups: ≤10 years and >10 years. The study parameters included central corneal thickness (CCT), endothelial cell density (ECD), coefficient of variation (CV) and percentage of hexagonal cells (% HEX) using Topcon specular microscope by the same observer.
Results: Mean CCT was observed to be significantly greater in diabetic eyes (516.51 ± 20.83 µm) than in control group (507.42 ± 28.41 µm) (p=0.0391). Mean CV was higher in endothelial cells of diabetic corneas (34.20 ± 4.15) than non-diabetic corneas (32.89 ± 2.98) (p=0.041). The diabetic group had lower mean ECD and percentage of hexagonal cells than the control group, without any statistical significance (p=0.092 & p=0.085, respectively). Of 65 patients with diabetes, 29 were with duration of DM ≤10 years and 36 with duration of DM >10 years. No statistically significant difference was noticed on comparing the corneal parameters among these two diabetic groups. Also, no significant correlation was observed between these endothelial parameters and duration of diabetes.
Conclusion: Diabetics have thicker corneas and increased polymegathism of endothelial cells in comparison to age-matched non diabetics, whereas density and hexagonality of endothelial cells was found to be similar between the two groups. The effect of diabetes duration on these endothelial parameters is insignificant in this study.