Corneal endothelial cell characteristics and central corneal thickness in patients with type 2 diabetes mellitus

Purpose: To evaluate the morphological features of corneal endothelium and central corneal thickness (CCT) in patients with type 2 diabetes mellitus (DM) and to correlate them with the duration of diabetes and patients glycemic status. Design: This was a prospective, cross-sectional, comparative, hospital-based study. Materials and Methods: The present study was conducted on 192 diabetics and 192 age- and sex-matched healthy controls. Corneal endothelial cell characteristics, CCT were measured using a specular microscope. Statistical comparisons were done between the case and controls using the appropriate parametric or nonparametric test. The associations between the various parameters were studied using the Pearson coefficient of correlation. Results: The mean corneal endothelial cell density (CECD) in the diabetic group (2521.3 ± 300.7 cells/mm2) was significantly lower compared to the nondiabetic group (2629.3 ± 221 cells/mm2) ( P < 0.001). The mean CCT in diabetic group was significantly higher (532.00 ± 24.88 μm) compared to control group (499.47 ± 24.76 μm) ( P < 0.001). The co-efficient of variation though higher and hexagonality though lower in diabetics was not statistically significant. CCT showed a significant positive correlation with duration of DM (r = 0.566, P<0.001). A weak positive correlation was observed between CCT and HBA1C ( r = 0.271, P<0.001) No correlation between CECD and CCT for diabetics with a duration of >10 years when compared with those with a duration of <10 years was observed. Conclusion: Diabetic patients in our study had thicker corneas, decreased CECD, and hexagonality, more irregular cell size than that of age matched controls. However, duration of the disease and the glycemic control did not affect these parameters.