Corneal and epithelial thickness mapping in diabetic patients using optical coherence tomography

To evaluate corneal and epithelial thickness using the anterior segment optical coherence tomography and to correlate these changes with major disease parameters, that is duration of the disease, status of control (glycated hemoglobin level), and stage of diabetic retinopathy. Corneal and epithelial thickness profile of 25 patients diagnosed with diabetes mellitus and 25 healthy individuals were measured by anterior segment optical coherence tomography. Full ophthalmological examination of all patients was done. The disease duration and the glycated hemoglobin levels were recorded. In diabetic patients, there was nonsignificant thinning in mean central epithelial thickness (P=0.14). The mean central corneal thickness is slightly thicker, however, it did not reach significance (P=0.051). There was statistically significant thickening in central stromal thickness (P=0.015). There was a significant negative correlation between the severity of retinopathy and superior epithelial thickness (P=0.037). The duration of the disease showed significant correlation with most of epithelial thickness values, however, HA1c level was not found to have any statistically significant effect on corneal and epithelial parameters. Chronic metabolic stress of diabetes has an impact on corneal epithelium and stroma. Severity of diabetic retinopathy should be considered as a risk factor during corneal surgeries to avoid epithelial and stromal-associated complications.