Corneal Epithelial Mapping Characteristics in Normal Eyes Using Anterior Segment Spectral Domain Optical Coherence Tomography

Purpose: The detailed mapping characteristics of the corneal epithelial thickness (CET) in normal eyes from a Middle Eastern population were investigated in relation to age, sex, intraocular pressure, and keratometric power (K). Methods: A retrospective cross-sectional and analytical study was conducted using spectral domain optical coherence tomography (OCT). We calculated the CET in 124 subjects in 17 zones within a 6 mm circle. Exclusion criteria included subjects with dry eyes, keratoconus, previous eye surgery, glaucoma, and irregular corneas. Results: A total of 124 individuals was composed of 64 males and 60 females. Themean age of this populationwas 45.52, ranging from18 to 79 years. The central CETwas thicker in the central 2 mm than the other zones of the cornea except the nasal, inferior-nasal, inferior and inferior-temporal zones, respectively. Males have thicker CET than females in all zones except in the peripheral nasal zone. We found a positive and significant correlation between age and CET in the central, superior-peripheral, inferior-paracentral, and inferior-temporal paracentral zones. Additionally, a medium-positive correlation was detected between increasing age and the variability of epithelial spectral domain in different zones. No link between CET and intraocular pressure was found. Conclusions: This study analyzed 17 CET zones within the central 6 mm, where the central epithelium is resistant to aging. The CET was thinner superiorly than inferiorly. This may help in decision-making in refractive procedures and in the prediction of corneal diseases. Translational Relevance: OCT novel algorithms are noninvasive methods for measuring CET and have been demonstrated to be useful in refractive surgery planning and follow-up, as well as a robust tool for diagnosing potential corneal ectasia.

Automated summary

This study investigates the mapping characteristics of corneal epithelial thickness (CET) in a Middle Eastern population and its relationship with age, sex, intraocular pressure, and keratometric power (K). The results show that the central CET is thicker than other zones of the cornea, males have thicker CET than females, and there is a positive correlation between age and CET. The findings of this study are important for refractive surgery decision-making and predicting corneal diseases.