Treatment-induced changes in higher-order aberrations after ray-tracing-guided vs. wavefront-optimized laser in situ keratomileusis

PURPOSE: Intraindividual comparison of treatment-induced changes of ocular higher-order aberrations (HOAs) after ray-tracing-guided laser in situ keratomileusis (LASIK) and wavefront-optimized LASIK. SETTING: University hospital. DESIGN: Prospective, randomized, eye-to-eye comparative study. METHODS: Patients with myopia and myopic astigmatism underwent ray-tracing-guided wavelight plus (Alcon) LASIK in one eye and wavefront-optimized LASIK in the fellow eye. The study assessed treatment-induced changes (3 months postoperative - preoperative) in root-mean-square (RMS) of total HOAs, primary spherical aberration, RMS coma and RMS trefoil after wavelight plus and wavefront-optimized LASIK. RESULTS: Thirty patients (sixty eyes) were included in the study. The mean change (± standard deviation) in RMS of total HOAs at 6-mm zone of analysis was 0.00±0.15µm after wavelight plus (p=0.758) and 0.11±0.12µm after wavefront-optimized LASIK (p<0.001). A negative spherical aberration change of -0.07±0.13µm (p=0.012) occurred after wavelight plus and a positive change of 0.06±0.09µm (p<0.001) after wavefront-optimized treatment. Changes in coma and trefoil were 0.02±0.15µm (p=0.474) and -0.02±0.10µm (p=0.225) after wavelight plus, while after wavefront-optimized LASIK they were respectively, 0.10±0.13µm (p<0.001) and 0.02±0.06µm (p=0.058). In contralateral-eye comparison, wavelight plus resulted in lower total HOAs in all patients with elevated preoperative HOAs (RMS of total HOAs >0.30µm, n=13 patients) and in 70.6% of patients (n=12) with low preoperative HOAs (≤0.30µm, n=17 patients). CONCLUSIONS: Wavefront-optimized LASIK increased total HOAs, spherical aberration and coma, while no increase in HOAs was detected after wavelight plus. Spherical aberration decreased (negative change) after wavelight plus. The benefit of ray-tracing-guided LASIK tended to be larger in patients with higher preoperative HOAs.