Outcomes of high-fluence (7.2 J/cm2) accelerated collagen cross-linking in advanced keratoconus

PURPOSE: The purpose is to evaluate the effectiveness of accelerated collagen cross-linking (CXL) in treating eyes with advanced keratoconus. MATERIALS AND METHODS: This retrospective cohort study included 109 eyes from 96 patients with advanced keratoconus (preoperative maximum keratometry, Kmax ≥58 D). All patients underwent an accelerated epi-off CXL protocol (12 mW/cm 2 for 10 min; total fluence, 7.2 J/cm 22 ) and completed at least 12 months of follow-up. Corneal topography, manifest refraction, visual acuity, and endothelial cell density were assessed preoperatively and at 1, 6, and 12 months postoperatively. RESULTS: The study included 36 females and 60 males with a mean age of 25.57 ± 4.39 years. The mean preoperative Kmax was 63.56 ± 4.97 D, which decreased significantly to 60.31 ± 4.20 D at 12 months postoperatively ( P = 0.001). Central corneal thickness also showed a significant reduction, from 459.00 ± 31.84 μm preoperatively to a median of 449 μm (range: 357–502 μm) postoperatively ( P = 0.001). The thinnest corneal thickness decreased from 438.57 ± 32.05 μm to 426.56 ± 31.33 μm ( P = 0.001). Progression of Kmax was observed in 12 eyes (11%), while 82 eyes (75.2%) showed a reduction of ≥1 D. No significant endothelial cell loss was observed throughout the follow-up period. Corneal edema developed in two patients and resolved within 3 months, and one patient required keratoplasty due to corneal decompensation. CONCLUSION: In eyes with advanced keratoconus, accelerated collagen cross-linking with 12 mW/cm 2 for 10 min can halt the progression of keratoconus without significant side effects over 12 months.