Corneal Epithelial Remodeling After Standard Epithelium-off Corneal Cross-linking in Keratoconic Eyes

To evaluate remodeling of the corneal epithelium after epithelium-off corneal cross-linking (CXL).

In this prospective single-center study, 93 eyes of 93 patients with progressive keratoconus underwent standard CXL. The maximum keratometry was assessed before and after CXL with Scheimpflug imaging, and the epithelial thickness profile across the central 5 mm of the cornea was assessed with spectral-domain optical coherence tomography anterior segment imaging.

The mean patient age was 27 ± 11 years; 76 patients (81%) were male and 17 (19%) were female. Between baseline and 6 months after CXL, the mean corneal maximum keratometry flattened from 58.90 to 57.80 diopters (P < .0001). The mean minimum epithelial thickness increased slightly (from 41 ± 6 to 42 ± 7 μm, P = .12), whereas the mean maximum epithelial thickness decreased slightly (from 65 ± 6 to 64 ± 7 μm, P = .067), reducing the net difference between the minimum and maximum epithelial thickness (from 24 ± 9 to 22 ± 9 μm, P = .0023). The difference between the minimum and maximum epithelial thickness was strongly positively correlated with the maximum keratometry reading at baseline (R² = 0.38) and at 6 months after CXL (R² = 0.59).

Epithelium-off CXL resulted in modest regularization of the epithelial thickness profile across the central 5 mm of the cornea at 6 months. This could slightly mask flattening of the underlying stroma. [J Refract Surg. 2018;34(6):408-412.].