Evaluation of the corneal endothelium in patients with diabetes mellitus type I and II

Summary. Background: The aim of the present study is to determine corneal physiology and endothelial morphology after proper image analysis technique in type I and II diabetic patients. The HbA1c level and the grade of retinopathy were also recorded and correlated with the endothelial parameters. Methods: 41 eyes of 21 patients with type I and 59 eyes of 30 patients with type II diabetes mellitus (mean age was 40.97±15.46 and 64.36±10.47 years) were examined and compared to age-matched controls. Endothelial cell density (ECD), mean cell area, coefficient of variation of cell area, central corneal thickness, intraocular pressure, and grade of retinopathy were recorded. Results: There was a statistically significant decreased endothelial cell density in type I disease (2428±219 cell/mm 2 ) in comparison with healthy subjects (2495±191 cell/mm 2 , P=0.02). The diabetic corneas were thicker than normal (P=0.001). The HbA1c level was inversely correlated with the ECD (r=-0.60; P<0.0001) and correlated with the mean endothelial cell area (r=0.60, P<0.0001). Significant correlation was observed between the endothelial morphology and grade of diabetic retinopathy (r=-0.40, ECD; r=0.38, mean cell area; P=0.01 for both). In type II diabetes mellitus no significant difference was found in the evaluated values. Conclusions: The present study disclosed the alteration of the corneal endothelial morphology in type I diabetes mellitus as compared to normal subjects. The results indicated that type I diabetic corneas are more susceptible to environmental changes than type II corneas.