Corneal Endothelial Pathology and Thickening in Early Diabetes Mellitus

Purpose: To compare endothelial properties and central corneal thickness (CCT) between nondiabetic and early type-two diabetic (T2DM) patients with good glycemic control. Methods: This is a retrospective case-control study. We included patients who were diagnosed with T2DM in the previous 10 years, and nondiabetic patients, who underwent a comprehensive ocular examination and specular microscopy. Endothelial Cell Density (ECD), CCT and the coefficient of variation were measured and compared. Results: A total of 312 eyes from 180 patients were included in this study: 118 eyes in the T2DM group, and 194 eyes in the nondiabetic group. No statistically significant differences were found between groups in terms of age and sex distribution (p = 0.08; p = 0.49, respectively). Mean ECD was significantly lower in the diabetic group (2467.8 ± 334.5 and 2553.5 ± 289.2, respectively; p = 0.028). CCT was significantly greater in the diabetic group (558.8±48.8 and 547.1±44.6, respectively, p = 0.034). No statistically significant differences were found in Coefficient of Variation. Conclusions: The present study reveals significant differences between early T2DM and nondiabetic patients in ECD and CCT values. These changes are evident even in early disease with good glycemic control.