Non-topography-guided Photorefractive Keratectomy for the Correction of Residual Mild Refractive Errors After ICRS Implantation and CXL in Keratoconus

PURPOSE: To evaluate the safety and clinical outcomes of non-topography-guided photorefractive keratectomy (PRK) for the treatment of residual mild refractive errors 6 months after sequential intracorneal ring segment (ICRS) implantation and corneal collagen cross-linking (CXL) in stable keratoconus. METHODS: This retrospective study included 17 eyes of 14 patients with mild to moderate keratoconus. The ICRS implantation and CXL were performed sequentially with a 4-week interval and non-topogra-phy-guided PRK was performed at least 6 months after CXL. Data were collected preoperatively and at the 6-month follow-up visits. RESULTS: ICRS implantation and CXL induced a significant decrease in keratometry and refraction and an increase in visual acuity. At the 6-month follow-up after ICRS implantation and CXL, uncorrected and corrected distance visual acuity (UDVA and CDVA) significantly improved from 1.17 +/- 0.38 and 0.44 +/- 0.09 logMAR preoperatively to 0.45 +/- 0.11 and 0.17 +/- 0.08 logMAR (P = .001) postoperatively, respectively. The mean spherical error decreased from -5.45 +/- 1.64 to -2.57 +/- 1.15 D (P = .01) and the mean cylinder from 3.86 +/- 1.15 to 2.13 +/- 1.11 D (P = .01). At the 6-month follow-up after PRK, UDVA significantly improved to 0.18 +/- 0.06 logMAR and CDVA was 0.15 +/- 0.05 logMAR. The mean spherical error and mean cylinder significantly decreased to -1.10 +/- 0.41 D (P = .02) and 0.98 +/- 0.37 D (P = .046), respectively. No intraoperative or postoperative complications occurred. CONCLUSIONS: At the 6-month follow-up, non-topography guided PRK after ICRS implantation and CXL was found to be an effective and safe option for correcting residual refractive error and improving visual acuity in patients with moderate keratoconus.