Wide Corneal Epithelial Mapping Using an Optical Coherence Tomography.

Purpose To map the corneal epithelium using a map measuring 9 mm in diameter and view the effects of age, sex, and axial length. Additionally, we wanted to demonstrate the reproducibility of this technique. Methods We calculated the epithelial thickness in 220 individuals using an SD-OCT machine with the newly released commercially available algorithm. We included normal eyes with refractive errors between +5 and -6 diopters (D). We excluded patients with an intraocular pressure of >22 mm Hg, history of cataract, previous ocular surgery, or disease and those with corneal pathology. Additionally, we excluded patients with evidence of systemic disease or pregnancy. Lastly, reproducibility was measured in 50 individuals. Results We found the center of the corneal epithelium to be thicker than the peripheral in all zones except the nasal (P = 0.124). The superior quadrant was found to be the thinnest while the inferior was the thickest. Males had a thicker epithelium in all locations except the superior outer section (P = 0.123). Three zones had a weak correlation with age: outer superior (P = 0.039, R = -0.152); outer temporal (P = 0.042, R = -0.150); and outer superior temporal (P = 0.011, R = -0.187). There was no significant relationship with the axial length. We found good to excellent reproducibility when using this technique in the central as well as the peripheral cornea. Conclusions We provide a comprehensive study in healthy, normal eyes using a novel algorithm to map the corneal epithelium with a wide diameter. This study can be used as a reference for future research.