Anterior Segment Ocular Coherence Tomography (as-oct) Based Central Corneal Epithelial Thickness (Ccet) as a Potential Biomarker for Diabetic Keratopathy: an Observational Study on Diabetic Patients in North India

Abstract

Abstract Background: The effect of Diabetes Mellitus on central corneal epithelial thickness (CCET) and central corneal thickness (CCT) can be measured by the non-invasive ASOCT technique, which may serve as the potential diagnostic and prognostic biomarker for detecting diabetic-induced keratopathy in the early stage Objective: This study aimed to evaluate central corneal epithelial thickness (CCET) and central corneal thickness (CCT) among diabetic subjects and to compare the results with non-diabetic subjects. Design: Observational cross-sectional study Methods: The study was conducted at a tertiary eye care center of in North India, wherein (n=75 eyes) of 75 diabetic patients (diabetic group) and (n=75 eyes) of 75 healthy subjects (control group) underwent Anterior Segment Ocular coherence tomography (AS-OCT) based measurement of CCET and CCT corresponding to 5-mm diameter area of the cornea. Tear film breakup time (TBUT) and Schirmer's test measurements were recorded. The data obtained were compared between the diabetic and control group. Results: The mean CCET in the diabetic group (47.09 ± 7.09 µm) was thinner compared to the control group (50.19 ± 5.92 µm), and the difference was statistically significant (p=0.004). There was no statistically significant difference (p=0.85) between the mean CCT in the diabetic group (520.21 ± 35.01 µm) and the control group (519.04 ± 40.32 µm). The mean TBUT was significantly lower among the diabetic group (p=0.001), but the Schirmer test values were non-significant (p= 0.06). In the diabetic group, the duration of diabetes had a statistically significant negative correlation with CCET (Rs=-0.81) and TBUT (Rs=-0.51). Conclusion: The CCET and TBUT were reduced among diabetic subjects, and the reduction was higher with the increased disease duration. The measurement of baseline CCET and T-BUT values along with serial monitoring may be a valuable tool to detect the early progression of diabetic eye disease and may emerge as a valid adjunctive biomarker for diabetic keratopathy.