A Comparison of LASIK Outcomes for High Versus Low Myopia: Large Data Analysis

PURPOSE: To compare the visual and refractive outcomes of low versus high myopic correction using laser in situ keratomileusis (LASIK) surgery. METHODS: Patients who underwent myopic LASIK between January 2013 and December 2023 were included. Eyes were divided into two groups based on preoperative myopia severity: low (0.50 to 3.00 diopters [D]) and high (≥ 6.00 D). Adjustments were made to account for differences in baseline and intraoperative parameters. RESULTS: In this retrospective study, 12,074 eyes of 6,985 patients were included. Mean spherical equivalent (SEQ) was-6.84 D for high myopia and-2.02 D for low myopia. High myopia was found in 6.7% of patients (n = 813), demonstrating preoperative steeper corneas (maximum keratometry 44.49 vs 44.21 D, P <.001) and worse uncorrected and corrected distance visual acuity (UDVA and CDVA) (2 vs 0.77 logMAR, P <.001; 0.03 vs 0.02 logMAR, P <.001, respectively). Following LASIK, the high myopia group had worse UDVA (0.04 vs 0.01 logMAR, P <.001) and CDVA (0.03 vs 0.01 logMAR, P <.001), higher cylinder (-0.08 vs-0.05 D, P <.001), and SEQ (-0.12 vs-0.07 D, P =.015). Keratometry measurements were flatter in the high myopia group (average: 38.43 vs 41.83 D, P <.001). After accounting for differences in baseline and intraoperative parameters, all of the above-mentioned parameters remained statistically significant. High myopia was not associated with higher re-treatment rates (P =.27). CONCLUSIONS: Although LASIK surgery yielded satisfactory short-term outcomes in both low and high myopia, high myopia showed slightly less favorable refractive results. However, overall results were clinically acceptable in both groups. Similar re-treatment rates may reflect patient satisfaction or variability in surgeons’ thresholds for offering enhancement procedures.