Specular microscope as an accurate tool for analysing corneal endothelial cell changes in patients with type 2 diabetes mellitus at tertiary care hospital set up in Kanchipuram District

Background: Diabetic eye disease comprises a group of eye conditions that affect people with diabetes. These conditions include diabetic retinopathy, diabetic macular edema (DME), cataract, and glaucoma. All forms of diabetic eye disease have the potential to cause severe vision loss and blindness. Animal studies have also shown that corneal endothelial cells in diabetic rats have morphological abnormalities. These abnormalities include a decrease in endothelial cell density (CD) and hexagonality, as well as increased polymegathism, polymorphism, and central corneal thickness (CCT). Aim: To compare corneal endothelial cell changes such as endothelial cell density (ECD) percentage of polymegathism (coefficient of variation) along with central corneal thickness (CCT) in patients with type 2 diabetes mellitus with age-matched control subjects. Materials and methods: Totally 40 patients among them 20 Patients (40 eyes) with type 2 DM and 20 control (non-diabetic) subjects (40 eyes). The corneal endothelial structure and CCT were examined in all eyes by noncontact specular microscopy using KONAN MEDICAL Specular Microscope. The endothelial structure was studied for ECD, the coefficient of variation of cell area (CV), and percentage of hexagonal cells. Results were analyzed accordingly. Results: In our study, 20 patients (40) eyes with HbA1c were 8.5% (Group I) and 20 patients (40) eyes with HbA1c. 4.5% (Group II) Endothelial cell density was significantly lower in the diabetic cornea than in control group (P=0.34). In (Group I) CV was higher in the diabetic cornea (P=0.003). The diabetic cornea group had a lower percentage of hexagonal cells than the control group (II), but the difference was not statistically significant (P=0.503). Also, the diabetic cornea was thicker in (Group I) than the control group, (Group II) but not statistically significant (P=0.210). Conclusion: This study documented that type 2 DM causes a significant reduction of endothelial cell density and increased coefficient of variation (polymegathism). Also, the diabetic cornea has increased central corneal thickness and a lower percentage of hexagonal cells than normal subjects, but without statistical significance.