Corneal endothelium and central corneal thickness changes in patients with type 2 diabetes mellitus

Abstract

Background Understanding the effect of diabetes mellitus on the corneal endothelium is essential for developing effective strategies for early detection, monitoring, and management of diabetic eye disease. Aim The aim of this study was to investigate the changes in corneal endothelium and central corneal thickness (CCT) in patients with type 2 diabetes mellitus. Patients and methods This is a prospective, nonrandomized, comparative study that included 500 eyes of 500 participants that were divided into two groups: group A: 250 eyes of type 2 diabetic patients and group B: 250 eyes of healthy controls. The diabetic group was further subdivided into two subgroups based on the duration of diabetes (<10 years and >10 years) and glycemic control (uncontrolled diabetes and controlled diabetes). Specular microscopy was performed in all eyes. Results The CCT was significantly higher in the diabetic group (516.93±36.43 μm) than in the control group (503.47±41.89 μm) (P=0.001). However, the two groups were relatively similar in cell density (CD) (cells/mm2), coefficient of variation (%), and hexagonality, with no statistically significant differences (P>0.05 for all). The CD was significantly higher in the patients with a duration of diabetes less than 10 years than those with a duration more than 10 years (2834.04±268.54 vs. 2277.13±244.54 cells/mm2, respectively, P=0.001). In addition, the hexagonality was significantly less in those with the duration of diabetes of more than 10 years (P=0.005). The CD was significantly less in the uncontrolled group than in the controlled group (2292.27±263.4 vs. 2644.69±370.88 cells/mm2, respectively, P=0.001). Conclusion Diabetic patients may exhibit alterations in their corneal parameters, particularly the CCT and endothelial CD. These changes are more in diabetic patients with a disease duration of more than 10 years and those with poor glycemic control.