Evaluation of Corneal Structure and Endothelial Morphological Characteristics in Type 2 Diabetic and Non-Diabetic Patients

PURPOSE: To compare corneal structure and endothelial morphological features between patients with type 2 diabetes mellitus (DM) and non-diabetic patients; and determine if the DM duration, glycated hemoglobin (HbA1c) levels, and diabetic retinopathy (DR) stage affect corneal morphological properties. PATIENTS AND METHODS: Sixty diabetic patients and 47 age- and sex-matched controls were enrolled in this cross-sectional study. DM group was analyzed according disease duration, HbA1c levels, and presence of retinopathy. Endothelial cell density (ECD) and morphology (average and coefficient of variation [CV] of cell size, percentage of hexagonal cells) were recorded using non-contact specular microscopy. Central corneal thickness (CCT) and corneal volume were measured by scheimpflug tomography. Univariate and multivariate linear regression analyses were performed to evaluate the relationship between demographical, clinical, and ocular variables with CCT and ECD. RESULTS: There were no statistically significant differences in the endothelium cell density or morphology between DM and non-DM groups (p>0.05). Also, there was no statistical difference between groups for CCT or corneal volume (p>0.05). Multivariate linear regression analysis showed that older age (p=0.028) was significantly associated with lower ECD; CCT was found to be significantly greater in males (p<0.001) and positively associated with corneal volume (p<0.001). CONCLUSION: The present study did not find any statistically significant differences between the corneal structural and endothelial characteristics of diabetic and non-diabetic subjects; other demographical parameters, such as age and gender, seem to be more determinant for the corneal properties.