Three-year results of accelerated transepithelial cross-linking (30 mW/cm(2) × 3 min) for keratoconus: a prospective study

OBJECTIVE: To assess the long-term efficacy and safety of accelerated transepithelial corneal cross-linking (ATE-CXL) with 30 mW/cm(2) × 3 min. METHODS AND ANALYSIS: Thirty-four eyes of 23 patients with progressive keratoconus (KCN) recruited within a single centre were enrolled in this prospective interventional study. Exclusion criteria included: history of Descemet’s membrane rupture, glaucoma, uveitis, severe dry eye, concurrent corneal infections, and systemic disease that could affect corneal healing. ATE-CXL was performed with 3 min of ultraviolet-A continuous irradiation (30 mW/cm(2)). Follow-up examinations were scheduled on postoperative day 1; 1 and 2 weeks; 1, 3 and 6 months; and 1, 2 and 3 years. Main outcome measures were maximum corneal power (Kmax), average corneal power (AvgK), steepest corneal power (Ks), central corneal thickness, thinnest corneal thickness, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA) and endothelial cell density. RESULTS: Mean Kmax, AvgK, Ks, UCVA, BCVA and endothelial cell density did not significantly change over 3 years. The speed of progression obtained by linear regression analysis on corneal parameters (Kmax, AvgK, Ks) improved after ATE-CXL. All baseline parameters correlated with the postoperative Kmax slope. Two eyes underwent ATE-CXL redo because of continued progression after the primary CXL. CONCLUSION: This is the first report of 3-year results of ATE-CXL with 30 mW/cm(2) × 3 min. ATE-CXL (30 mW/cm(2) × 3 min) was safe and effective for slowing down KCN progression. TRIAL REGISTRATION NUMBER: This study was registered with ID UMIN000009372 in UMIN-Clinical Trials Registry.