Central Corneal Thickness and Endothelial Cell Changes after Phacoemulsification in Patients with Diabetes Mellitus: A Prospective Study

Introduction: Diabetes Mellitus (DM) has emerged as a significant cause of ocular morbidity. The toxic effects of hyperglycaemia spare no cell in the body and cornea, has also revealed certain changes in diabetic patients. Higher phacoemulsification time and power effect corneal endothelial cells. This can inflict an additional stress on the altered diabetic corneal endothelium. Aim: To compare the Central Corneal Thickness (CCT) thickness and endothelial Cell Density (CD) and morphology in Type 2 Diabetes Mellitus (T2DM) patients undergoing phacoemulsification with age-matched non diabetic controls undergoing phacoemulsification. Materials and Methods: A prospective, hospital-based, interventional study was conducted in the Department of Ophthalmology, Government Medical College, Jammu, Jammu and Kashmir, India. The duration of the study was nine months, from April 2021 to December 2021. The study included 50 patients with T2DM and 50 non diabetic controls. All patients underwent phacoemulsification performed by a single surgeon. The CCT and endothelial cell parameters were measured preoperatively and postoperatively at one week, six weeks and three months using Topcon specular microscope. Postoperative changes in the corneal endothelial cells were compared between the two groups for a period of three months. Statistical analysis was done by using the Statistical Package for Social Sciences (SPSS) version 25.0 (IBM Corp. Released 2017. Armonk, NY, USA). Categorical variables were analysed using Chi-square test and the groups were compared using Student’s t-test. Results: The mean age of the study participants was 63.22±7.52 years in diabetic group and 64.52±7.29 years in non diabetic group. Diabetic patients showed significantly greater corneal thickness than non diabetic controls (p=0.034). This pattern was observed till the last follow-up at three months. The endothelial cell parameters were comparable between diabetic and non diabetic patients. There was a fall in endothelial cell count in all patients postoperatively, but it was significantly higher in the diabetic patients at three months (p=0.048). Postoperatively, Co-efficient of Variation (CV) was significantly higher in diabetic patients (p=0.001) accompanied by a decreased hexagonality (p=0.039) at the end of three months. Conclusion: A diabetic cornea is different than a non diabetic cornea at the cellular level. Diabetics show accelerated corneal endothelial cell loss and greater variation in cell morphology in response to surgical stress. Diabetes mellitus is a risk factor for endothelial cell loss in patients undergoing cataract surgery