One-Year Results of Simultaneous Topography-Guided Photorefractive Keratectomy and Corneal Collagen Cross-Linking in Keratoconus Utilizing a Modern Ablation Software
Purpose.To evaluate effectiveness of simultaneous topography-guided photorefractive keratectomy and corneal collagen cross-linking in mild and moderate keratoconus.Methods. Prospective nonrandomized interventional study including 20 eyes of 14 patients with grade 1-2 keratoconus that underwent topography-guided PRK using a Custom Ablation Transition Zone (CATz) profile with 0.02% MMC application immediately followed by standard 3 mw/cm2UVA collagen cross-linking. Maximum ablation depth did not exceed 58 μm. Follow-up period: 12 months.Results.Progressive statistically significant improvement of UCVA from0.83±0.37logMAR preoperative, reaching0.25±0.26logMAR at 12 months (P<0.001). Preoperative BCVA (0.27±0.31logMAR) showed a progressive improvement reaching0.08±0.12logMAR at 12 months (P=0.02). MeanKmax reduced from48.9±2.8to45.4±3.1 D at 12 months (P<0.001), meanKmin reduced from45.9±2.8 D to44.1±3.2 D at 12 months (P<0.003), mean keratometric asymmetry reduced from3.01±2.03 D to1.25±1.2 D at 12 months (P<0.001). The safety index was 1.39 at 12 months and efficacy index 0.97 at 12 months.Conclusion. Combined topography-guided PRK and corneal collagen cross-linking are a safe and effective option in the management of mild and moderate keratoconus.Precis. To our knowledge, this is the first published study on the use of the CATz ablation system on the Nidek Quest excimer laser platform combined with conventional cross-linking in the management of mild keratoconus.