Comparison of Visual Outcomes With Different Ablation Profile in FS-LASIK for High Myopia Correction: Ray-Tracing-Guided Versus Custom-Q

Purpose: To compare visual outcomes in patients with high myopia undergoing individualized ray-tracing–guided femtosecond laser–assisted laser in situ keratomileusis (FSLASIK) versus Q-value-adjusted (Custom-Q) FS-LASIK. Methods: This prospective contralateral-eye study included 66 eyes of 33 patients with high myopia requiring FS-LASIK. Ray-tracing–guided treatment was performed in one eye and Custom-Q ablation in the fellow eye. For ray-tracing– guided treatment, the ablation profile was generated using a ray-tracing algorithm and subsequently adjusted based on manifest refraction. Follow-up examinations were conducted at 1 day, 1 week, 1 month, and 3 months postoperatively. Visual acuity, manifest refraction, and higher order aberrations (HOAs) were assessed preoperatively and postoperatively. Results: At 3 months postoperatively, uncorrected distance visual acuity (UDVA) of 20/16 or better was achieved in 79% of eyes in the ray-tracing–guided group and 73% in the Custom-Q group. The mean UDVA was −0.10 ± 0.07 logarithm of the minimum angle of resolution (logMAR) in the ray-tracing– guided group and −0.09 ± 0.09 logMAR in the Custom-Q group, with no statistically significant difference between groups ( P = .552). Compared with the Custom-Q group, the ray-tracing– guided group showed a tendency toward mild hyperopic shift. Both groups demonstrated significant increases in total HOAs and coma in the 4-mm and 6-mm zones (all P < .05), as well as a significant decrease in SA in the 4-mm zone ( P < .001). In the 6-mm zone, no statistically significant increase in SA was observed after surgeon-adjusted ray-tracing–guided FSLASIK ( P = .085), and postoperative SA was lower than that in the Custom-Q group ( P = .002). Conclusions: Individualized surgeon-adjusted ray-tracing– guided FS-LASIK was safe and effective for correcting high myopia, although a mild tendency toward overcorrection was observed. Compared with Custom-Q ablation, it was associated with lower postoperative SA, particularly at larger optical zones.