Topography-guided Transepithelial PRK After Intracorneal Ring Segments Implantation and Corneal Collagen CXL in a Three-Step Procedure for Keratoconus

PURPOSE: To present the results of topography-guided transepithelial photorefractive keratectomy (PRK) after intracorneal ring segments implantation followed by corneal collagen cross-linking (CXL) for keratoconus. METHODS: In this prospective case series, 10 patients (16 eyes) with progressive keratoconus were included. All patients underwent topography-guided transepithelial PRK after Keraring intracorneal ring segments (Mediphacos Ltda) implantation, followed by CXL treatment. The follow-up period was 6 months after the last procedure for all patients. Time interval between both intracorneal ring segments implantation and CXL and between CXL and topography-guided transepithelial PRK was 6 months. RESULTS: LogMAR mean uncorrected distance visual acuity and mean corrected distance visual acuity were significantly improved (P<.05) from 1.14±0.36 and 0.75±0.24 preoperatively to 0.25±0.13 and 0.13±0.06 after the completion of the three-step procedure, respectively. Mean spherical equivalent refraction was significantly reduced (P<.05) from -5.66±5.63 diopters (D) preoperatively to -0.98±2.21 D after the three-step procedure. Mean steep and flat keratometry values were significantly reduced (P<.05) from 54.65±5.80 D and 47.80±3.97 D preoperatively to 45.99±3.12 D and 44.69±3.19 D after the three-step procedure, respectively. CONCLUSIONS: Combined topography-guided transepithelial PRK with intracorneal ring segments implantation and CXL in a three-step procedure seems to be an effective, promising treatment sequence offering patients a functional visual acuity and ceasing progression of the ectatic disorder. A longer follow-up and larger case series are necessary to thoroughly evaluate safety, stability, and efficacy of this innovative procedure.