Corneal endothelial changes in type 2 diabetes mellitus before and after cataract surgery

Purpose The aim of the study was to investigate the differences in corneal endothelium between patients with and those without diabetes before and after phacoemulsification with intraocular lens implantation. Design The study was designed as an interventional prospective comparative investigation. Setting The study was conducted at Mansoura Ophthalmic Centre, Faculty of Medicine, Mansoura University, Egypt. Patients and methods A total of 100 eyes of 99 patients (49 with and 50 without type 2 diabetes) with senile cataract underwent phacoemulsification with foldable intraocular lens implantation. Specular microscopy was performed preoperatively, at 1 week, and at 3 months postoperatively to evaluate endothelial cell density (ECD), endothelial cell size variability [coefficient of variation (CV)], and central corneal thickness (CCT). Data were analyzed using the t-test, the Mann-Whitney U-test, and Pearson′s correlation coefficient. Results Preoperatively, the mean ECD was 2558.20 cells/mm 2 , the mean CV was 39.84%, and the mean CCT was 512.56 μm in diabetic patients. In controls, the mean ECD was 2484.31 cells/mm 2 , mean CV was 41.03%, and mean CCT was 507.20 μm. There were no significant differences between the two groups (P = 0.145, 0.338, and 0.450 respectively). At 3 months postoperatively, the mean endothelial cell loss (ECL) was 8.09%, mean CV increase was 2.38%, and mean CCT increase was 3.00 μm in diabetic patients, whereas in controls the mean ECL was 8.36%, mean CV increase was 1.06%, and mean CCT increase was 1.30 μm. No significant difference was found in ECL between the two groups (P = 0.850), whereas the increases in CV and CCT were significantly more in diabetic patients than in controls (P = 0.001 and 0.031, respectively). Conclusion There was no significant difference in the corneal endothelium preoperatively between diabetic and nondiabetic patients. Although no significant difference was found in ECL following phacoemulsification between the two groups, diabetic patients had a significantly greater increase in CV (polymegathism) and CCT compared with nondiabetic patients.