Study of corneal endothelial cells in diabetic patients

Abstract

Background: The cornea is the anterior transparent part of the eye. In addition to its optical and refractive function, it is an important protective structure. Aim: The aim of this study was to assess corneal endothelium (counts, morphology and structure) as well as corneal thickness of Type 2 diabetic participants. Setting: This is a hospital-based case–control study and was carried out at Ibn Al Haitham tertiary eye hospital in Baghdad, Iraq. Methods: The sample size was 240 eyes of 120 diabetic participants and 120 healthy participants. Non-contact specular microscopy was utilised to evaluate corneal endothelial cells, including endothelial cell density (ECD), coefficient of variation in cell area (CV), hexagonality (HEX) of cells as well as central corneal thickness (CCT). Results: The ECD was lower in the diabetic corneas (2584.87 ± 259.15 cell/mm2) compared with the healthy corneas (2717.56 ± 289.67 cell/mm2) (p = 0.017, statistically significant). Coefficient of variance (CV) was greater in the diabetic group (40.8 ± 4.17) as opposed to the group with healthy corneas (37.3 ± 2.89) (p = 0.019, statistically significant). The corneas of the diabetic group showed lower hexagonality (44.36% ± 9.87%) compared with the healthy corneas (59.35% ± 9.67%) (p < 0.001, statistically significant). Furthermore, the corneas of the diabetic group had greater central thickness (581.1 ± 32.4 μm) when compared with the control group (511.8 ± 29.8 μm), (p < 0.001, statistically significant). No correlation was found between the severity level of diabetic retinopathy and corneal endothelial pathological alterations. Conclusion: Long-term poorly controlled glycaemia has a remarkable impact on corneal endothelium (counts, morphology and structure) as well as corneal thickness.