One-Year Efficacy and Safety of Combined Photorefractive Keratectomy and Accelerated Corneal Collagen Cross-Linking after Intacs SK Intracorneal Ring Segment Implantation in Moderate Keratoconus

Figure 2

Changes in various parameters before and after the two-staged multimodal surgery for keratoconus. The error bars are the 95% confidence intervals of medians (spherical equivalent, cylinder, and spherical aberration) or means (the others). The spherical equivalent and the cylinder are measured by autorefraction. , P < 0.001; , P < 0.01; , P < 0.05; ns, not significant (Friedman test and Dunn’s multiple comparisons test for spherical equivalent, cylinder, and spherical aberration; repeated ANOVA and Sidak’s multiple comparisons test for corneal thickness, keratometric measurements, RMS, and coma). PreRing, before intracorneal ring segment implantation; PrePlus, before PRK-CXL (“Plus” surgery); Plus1m, 1 month after PRK-CXL; Plus3m, 3 months after PRK-CXL; Plus6m, 6 months after PRK-CXL; Plus12m, 12 months after PRK-CXL; K, keratometry; RMS, root mean square higher-order aberration.