Assessment of Corneal Endothelium among Diabetic Patients in a Multispecialty Hospital in Tamil Nadu

Abstract

Introduction: Corneal damage is the common issue affecting 70% of diabetic patients. Diabetic cornea has functional abnormalities such as decreased corneal Endothelial Cell Density (ECD), thicker corneas with increased endothelial permeability, lesser corneal sensitivity, and elevated corneal auto-fluorescence. Aim: To study the corneal endothelial characteristics among diabetic patients and to identify the factors associated with endothelial damage and compare the corneal changes based on the duration of diabetes mellitus and glycaemic control. Materials and Methods: The hospital based cross-sectional study was conducted in 155 patients (100 diabetic and 55 control) from 24th September 2016 to 29th March 2018. The corneal endothelial morphological features were evaluated using a non-contact EM-3000 specular microscope. The morphological characteristics of endothelial cell like the ECD, Coefficient of Variation (CV), Central Corneal Thickness (CCT), and percentage of hexagonal cells were compared between diabetic patients and the control population. Age, gender, blood pressure, duration of diabetes, fasting and Postprandial Blood Sugar (PPBS) HbA1c value, blood urea, and serum creatinine, Intra Ocular Pressure (IOP) were also recorded, and the endothelial cell characteristics were compared between the diabetic groups according to the duration (< or ≥ 3 years) and HbA1c% (< or ≥ 7%). An independent t-test was performed to compare the means of endothelial characteristics between study subjects and the control group and also between duration of diabetes and HbA1C levels. A p-value of less than 0.05 was considered statistically significant. The data were analysed using a SPSS statistical program. Results: Baseline characteristics like Fasting Blood Sugar (FBS), PPBS, HbA1c, Systolic and Diastolic Blood Pressure (SBP and DBP) were significantly higher in diabetic group than control. A significant difference in corneal thickness (p=0.01) and hexagonality (p<0.001) were also observed between both the groups. The diabetic group showed a reduction in cell density and a higher coefficient variation of cell size however the differences were not statistically significant, There was no significant difference in the ECD, CCT, CV, and hexagonality irrespective to HbA1c level and duration of diabetes. Conclusion: Patients with diabetes had a significant increase in corneal thickness, and a higher frequency of pleomorphism compared to control subjects. In terms of ECD and co-efficient variation, no difference was observed between groups.