Sequential Topical Riboflavin With or Without Ultraviolet A Radiation With Delayed Intracorneal Ring Segment Insertion for Keratoconus

Purpose To report refractive, topographic, pachymetric, tonometric, and corneal biomechanical outcomes 24 months after corneal cross-linking (CXL), followed by insertion of intrastromal corneal ring segments (ICRS) in keratoconic eyes. Design Prospective randomized clinical trial. Methods settings: Institutional. study population: Thirty-nine eyes of 31 patients, allocated into 2 groups. intervention: Patients in the CXL group underwent corneal CXL with riboflavin and ultraviolet A (UVA) light. Patients in the riboflavin eyedrops group received riboflavin 0.1% (w/v) eyedrops – 20% dextran solution for 1 month. After 3 months, all patients underwent insertion of ICRS. main outcome measures: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and topography were evaluated at baseline, at 1 month and 3 months after CXL or riboflavin eyedrops, and again at 1-, 3-, 6-, 12-, and 24-month intervals after ICRS insertion. Results Mean (standard deviation [SD]) baseline UCVA and BSCVA in the CXL group and the riboflavin eyedrops group were 1.12 (0.59) and 0.84 (0.49), and 0.68 (0.43) and 0.45 (0.23), respectively; 24-month mean (SD) UCVA and BSCVA in the CXL group and the riboflavin eyedrops group were 0.79 (0.50) and 0.62 (0.28), and 0.52 (0.45) and 0.32 (0.21), respectively, with no statistically significant difference between groups ( P = .70 and P = .78).There were no statistical differences between groups postoperatively at 24 months for all 3 topographic parameters, flattest-K1 ( P = .81), steepest-K2 ( P = .68), and average keratometry (mean power; P = .52). Conclusions ICRS insertion, with or without prior CXL, showed no difference between groups in terms of refractive, topographic, pachymetric, tonometric, and corneal biomechanical results at 24 months.