Corneal epithelial remodeling following myopic ray-tracing-guided laser-assisted in situ keratomileusis: a clinical study.

Purpose: To evaluate corneal epithelial remodeling profile following ray-tracing-guided laser-assisted in situ keratomileusis (LASIK) for myopia.

Methods: This retrospective study enrolled 65 eyes from 33 patients undergoing ray-tracing-guided LASIK for myopia. Corneal epithelial thickness (CET) was measured across a 9-mm diameter area using RTVue XR OCT preoperatively and at 1, 3 and 6 months postoperatively. CET was analyzed by concentric zones and sections.

Results: Regionally, at 6 months, CET significantly increased in central (+4.28 μm, 7.8%), paracentral (+8.11 μm, 15.0%), midperiphery zones (+1.83 μm, 3.4%) (all P < 0.05) and unchanged in periphery zone (P = 1.000), with the most pronounced thickening in paracentral temporal and inferotemporal sections. Longitudinally, at 1 month, CET stabilized centrally (P = 1.000), significantly thickened paracentrally and thinned peripherally (both P < 0.05). From 1 to 3 months, central and paracentral zones significantly thickened (both P < 0.001). From 3 to 6 months, all zones stabilized (all P > 0.05). Notably, despite epithelial changes, neither significant regression nor increase of spherical aberration were observed at 6 months (both P > 0.05). Positive correlations were observed between changes in CET and both the amount of refractive error to be corrected and the ablation depth across all zones (all P < 0.05).

Conclusions: Ray-tracing-guided LASIK induced regionally and longitudinally non-uniform corneal epithelial remodeling. Despite corneal epithelial thickness increase, the visual and refractive outcomes were favorable and stable after the surgery.