Accelerated Epithelium-off Corneal Cross-linking With High Ultraviolet Energy Dose (7.2 J/cm 2 ) for Progressive Keratoconus: 2-Year Results in a Chinese Population

PURPOSE: To evaluate the results of epithelium-off continuous light accelerated corneal cross-linking (CXL) with a total dose of 7.2 J/cm 2 for treating progressive keratoconus in a Chinese population during 24 months of follow-up. METHODS: In this retrospective, interventional case series, 45 eyes of 31 consecutive patients with progressive keratoconus were evaluated. All patients underwent accelerated CXL with settings of 30 mW/cm 2 for 4 minutes, corresponding to a total dose of 7.2 J/cm 2 . Visual acuity, manifest refraction, epithelial thickness, topography, tomography, aberrometry, endothelial cell count, and intraocular pressure were evaluated at baseline and at 1, 3, 6, 12, 18, and 24 months postoperatively. RESULTS: Progressive keratoconus was stabilized in 91.11% and 93.33% of the patients at 12 and 24 months, respectively. The improvement in corrected distance visual acuity was significant throughout the postoperative follow-up period ( P < .05), excluding month 1. A significant decrease in the maximum keratometric values (0.67 ± 1.68, 0.92 ± 1.78, and 0.97 ± 1.73 D) was observed at months 12, 18, and 24, respectively ( P < .05 for all). Corneal irregularity improved, particularly total root mean square and higher order aberrations at 12 to 24 months after CXL. In bilateral CXL, the progression of the first eye was highly predictive of the outcome of the second eye. CONCLUSIONS: CXL with a total dose of 7.2 J/cm 2 maintains long-term results in halting the progression of keratoconus, with significant improvement in the corrected distance visual acuity and stability of keratometric values. Further clinical studies with longer follow-up periods and larger samples are necessary to confirm these results. [ J Refract Surg . 2020;36(11):731–739.]