Ten-year outcomes of effective optical zone and decentration analysis after keratorefractive lenticule extraction for...

To investigate ten-year changes in the effective optical zone (EOZ) and decentration after keratorefractive lenticule extraction (KLEx) for moderate and high myopia. In this prospective study, 27 patients (48 eyes, spherical equivalent: -6.34 ± 1.19 D) were enrolled and treated with KLEx. Follow-up was conducted 10 years postoperatively. The EOZ and decentration were calculated using custom software based on the tangential corneal curvature maps. The relationships among keratometry, corneal wavefront aberrations, EOZ, and decentration were evaluated. Ten years postoperatively, the safety and efficacy indexes were 1.14 ± 0.19 and 1.05 ± 0.25, respectively. The EOZ diameter was 5.31 ± 0.26 mm. In the longitudinal analysis, the percentages of (1-EOZ/POZ) were 31.02 ± 1.02%, 31.14 ± 1.08%, 33.22 ± 1.06%, and 34.91 ± 1.02% at postoperative 1 month, 1 year, 5 years, and 10 years. The differences between preoperative and postoperative higher-order aberrations (HOAs) were 0.23 ± 0.02 μm, 0.24 ± 0.02 μm, 0.21 ± 0.02 μm, 0.17 ± 0.02 μm. The factors influencing the EOZ percentages were time (p = 0.002), correction cylinders (p = 0.005), and interaction between correction cylinders and spheres (p = 0.014), and the factors influencing HOAs inductions were time (p = 0.001), scotopic pupil (p = 0.001), postoperative decentration (p < 0.001), EOZ diameter (p = 0.030), and the interaction between decentration and EOZ diameter (p = 0.002). The decentration was 0.39 ± 0.15 mm at the last follow-up, which was statistically unchanged throughout the follow-up. KLEx is safe and effective for patients with moderate or high myopia in the long term. The EOZ decreased slightly but was broadly stable, and the decentration remained stable during the 10-year follow-up.