One-year structural and functional outcomes of accelerated epithelium-off corneal cross-linking in keratoconus.

AIM: To evaluate the structural and functional outcomes of accelerated epithelium-off corneal collagen cross-linking (CXL) in patients with keratoconus (KC) 1y after treatment. METHODS: This retrospective study included patients who underwent an accelerated epi-off CXL for progressive KC at the Department of Ophthalmology, Sveti Duh University Hospital, Zagreb, Croatia, between January and December 2023. The protocol consisted of epithelial removal, riboflavin 0.1% instillation for 3min, and ultraviolet-A (UVA) irradiation at 9 mW/cm2 for 10min. Pentacam HR was used to assess keratometric parameters (Kmax, Kmean), curvature-based indices [index of surface variance, index of vertical asymmetry, keratoconus index, central keratoconus index, index of height asymmetry (IHA), index of height decentration, minimum sagittal curvature (Rmin)], pachymetry-based indices [central corneal thickness (CCT), average pachymetric progression index, maximum Ambrósio relational thickness], Belin/Ambrósio deviation, and the ABCD progression system preoperatively and at 12mo. RESULTS: A total of 45 eyes from 45 patients (mean age: 29.1±6.2y) were included in the study. One year after CXL treatment, only Kmax front (55.20 to 55.00 D) showed a statistically significant decrease among the keratometric parameters. A statistically significant reduction was observed in all curvature-based indices, except for IHA, which did not reach statistical significance, whereas Rmin (6.11 to 6.14 mm) showed a statistically significant increase. Additionally, CCT, anterior radius of curvature (ARC), and best-corrected distance visual acuity (BCVA) also demonstrated statistically significant increase. CONCLUSION: Accelerated epi-off CXL results in significant structural and functional improvements in KC at the 1-year follow-up. Decreased Kmax and curvature indices, increased Rmin, CCT, and ARC, and improved BCVA indicate better corneal regularity, biomechanical stability, and functional vision, with ABCD analysis confirming disease stabilization.