Corneal higher-order aberration changes after accelerated cross-linking for keratoconus

Abstract Aim To evaluate changes in corneal higher-order aberrations (HOAs) following epithelium-off accelerated corneal cross-linking (A-CXL) and to explore the impact on visual acuity. Methods In this retrospective case series, 32 eyes of 24 patients with keratoconus (KC) underwent A-CXL. Treatment was delivered at 10 mW/cm2 for 9 min with a total dose of 5.4 J/cm2. The following anterior corneal HOAs: total corneal HOAs, trefoil, secondary trefoil, coma, secondary coma, secondary astigmatism and spherical aberrations were analysed using the Scheimpflug-Placido Sirius (CSO, Italy) corneal topographer at baseline and 12 months following treatment. Multivariate analysis was used to evaluate the independent effect of HOA subtypes on changes in uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA). Results At one year post CXL, UDVA and CDVA were significantly improved, -0.13 ± 0.19 LogMAR (P = 0.0005) and -0.08 ± .0.11 LogMAR (P = 0.0003), respectively. The mean preoperative trefoil, secondary trefoil, secondary coma and secondary astigmatism were 0.95 ± 0.46; µm, 0.20 ± 0.11; µm, 0.29 ± 0.19; µm and 0.42 ± 0.17 µm, respectively. At one year, the mean values decreased significantly to 0.77 ± 0.47 µm, 0.15 ± 0.11 µm, 0.25 ± 0.18 µm and 0.34 ± 0.18 µm, respectively (P