Effect of Epithelium-Off Corneal Collagen Cross-Linking On Higher-Order Aberrations in Early Keratoconus

Keratoconus is a progressive corneal ectatic disorder characterized by stromal thinning and irregular corneal steepening, leading to visual distortion and reduced visual quality. Corneal collagen cross-linking (CXL) is an established treatment aimed at halting disease progression by improving corneal biomechanical stability. To evaluate the effect of epithelium-off corneal collagen cross-linking on corneal higher-order aberrations (HOAs) in patients with early keratoconus. This prospective interventional study included 40 eyes of 40 patients with early keratoconus who underwent standard epithelium-off riboflavin–UVA CXL. Corneal HOAs were measured preoperatively and six months postoperatively using Shack–Hartmann wavefront aberrometry. A statistically significant reduction in total RMS HOAs was observed at six months, particularly over a 6-mm pupil diameter (p < 0.001). Significant improvements were noted in horizontal and vertical coma as well as spherical aberration, while trefoil aberrations showed no significant change. Epithelium-off CXL significantly improves corneal higher-order aberrations in early keratoconus, especially coma and spherical aberrations, contributing to improved corneal optical quality.