Central and peripheral optical quality after FS-LASIK, SMILE, and phakic ICL implantation for moderate to high myopia

FS-LASIK, small-incision lenticule extraction (SMILE), and phakic intraocular lens (ICL) implantation are widely used for correcting moderate to high myopia, yet their effects on peripheral optical quality remain incompletely understood. This study compared central and peripheral optical outcomes after these three procedures using on-axis and off-axis wavefront measurements.

This retrospective comparative study included 598 eyes (18-35 years) that underwent FS-LASIK, SMILE, or phakic ICL implantation. Wavefront aberrations were measured preoperatively and at 6 months postoperatively, both centrally and at ± 30° eccentric fixation, using a modified Shack-Hartmann aberrometer. The measurements were reconstructed over a 4.5-mm pupil, ensuring consistency across subjects.Second-, third-, and fourth-order RMS aberrations, peripheral relative defocus, astigmatic vector J0, and horizontal coma were analyzed pre- and postoperatively, with inter-group comparisons and correlations with preoperative spherical equivalent (SE).

All procedures achieved high refractive accuracy with minimal surgically induced astigmatism. Second-order aberrations were substantially reduced in all groups. Third-order aberrations increased postoperatively, most prominently after FS-LASIK, followed by SMILE and then ICL implantation, while fourth-order changes were small and similar among groups. Peripheral relative defocus shifted toward hyperopia after all procedures, greatest after FS-LASIK. Induced higher-order aberrations and peripheral defocus were significantly correlated with preoperative SE, particularly in the FS-LASIK group.

Although FS-LASIK, SMILE, and phakic ICL implantation all provided effective correction of moderate to high myopia, they were associated with different patterns of postoperative central and peripheral optical change. In this cohort, phakic ICL implantation showed relatively smaller changes in peripheral optical quality measures, whereas FS-LASIK was associated with greater spherical equivalent-dependent increases in higher-order aberrations and peripheral hyperopic defocus. Peripheral wavefront assessment may provide clinically relevant information beyond central aberrometry.