Corneal collagen cross-linking (CXL) versus combined CXL and femtosecond laser-assisted intracorneal ring segment implantation for the treatment of keratoconus

Background The corneal cross-linking procedure has been proven to be an effective method to treat and stabilize keratoconus progression, but early vision rehabilitation is still needed in patients. Aim The aim was to compare the results of the combined CXL and intrastromal corneal ring segment implantation procedure to that of the cross-linking-alone procedure in terms of visual acuity, refraction, and some corneal topographic parameters in keratoconic patients. Design This was a prospective, comparative, and interventional study. Patients and methods This study was carried out on 44 keratoconic patients (60 eyes) of both sexes who ranged from 18 to 36 years. Thirty eyes were subjected to the CXL-alone procedure and 30 eyes were subjected to the combined procedure. Measurements were performed in all patients preoperatively and at 3, 6 months, and 1 year postoperatively including unaided visual acuity, best-corrected visual acuity, refractive, and topographic outcomes. Results Through the entire study period, both procedures were safe and effective in treating and stabilizing keratoconus progression. Furthermore, the combined group showed additional improvements over the CXL group for the following: UDVA at 3 months (P=0.0028), best-corrected visual acuity at 1 year (P=0.011), refractive and keratometric astigmatism at all follow-up visits and corneal asphericity at 3 months (P=0.013) and 6 months (P=0.0221) of follow-up. No severe intraoperative or postoperative complications were observed during the entire study period in either group. Conclusions The combined procedure is safe and effective for earlier improvement of visual and refractive outcomes in addition to the corneal stabilizing effect.