Changes in the corneal endothelial cell density and morphology in patients with type 2 diabetes mellitus: a population-based study, Sankara Nethralaya Diabetic Retinopathy and Molecular Genetics Study (SN-DREAMS, Report 23).

Purpose: To study the corneal endothelial cell density and morphological features in type 2 diabetic patients (cases) and compare it with nondiabetic subjects (controls) in a population-based cross-sectional study.
Methods: Patients were recruited from the Sankara Nethralaya--Diabetic Retinopathy Epidemiology and Molecular Genetic Study, a population-based study to estimate the prevalence of type 2 diabetes and diabetic retinopathy in urban Chennai, South India. Corneal endothelial morphological features were recorded in all subjects using noncontact specular microscopy and central corneal thickness was measured using ultrasound pachymeter.
Results: A total of 1191 cases and 121 controls were enrolled into the study. The mean corneal endothelial cell density (cells/mm(2)) was lower in cases than in controls (2550 ± 326 vs. 2634 ± 256; P = 0.001). No difference was observed in the mean pachymetry values, hexagonality %, and coefficient of variation of cell size between cases and controls. Multivariate regression analysis, after adjusting for age, showed the mean cell density to be lesser by 66 cells/mm(2) (95% confidence interval, 6.3-125.9) among diabetic patients compared with nondiabetic subjects.
Conclusions: The results of this study, from a large population-based sample, support the earlier theories of lower endothelial cell counts among subjects with type 2 diabetes mellitus in comparison with nondiabetic controls.