Ray-Tracing-Guided LASIK: Refractive and Visual Outcomes and the Role of Higher Order Aberrations in Visual Gain.

PURPOSE: To evaluate the safety and efficacy of ray-tracing-guided laser in situ keratomileusis (LASIK) and to investigate the associations among visual line gain, higher order aberrations (HOAs), and manifest refraction spherical equivalent (MRSE).

METHODS

This retrospective study enrolled 285 eyes of 143 participants who underwent ray-tracing-guided LASIK, and measurements including visual acuity, manifest refraction, and whole-eye aberrations at a 6-mm diameter pupil, with examinations performed preoperatively and at 1 day, 1 week, 1 month, and 3 months postoperatively.

RESULTS

At 3 months postoperatively, 93.7% of eyes achieved uncorrected distance visual acuity (UDVA) of 20/20 or better, and 62.8% of eyes gained one or more visual lines of UDVA compared with preoperative corrected distance visual acuity (CDVA) (right eye: 62.9%; left eye: 62.7%). MRSE, astigmatism, astigmatism vectors, and HOAs were effectively corrected and well controlled. As UDVA improved postoperatively, trefoil decreased significantly compared with the pre-operative level (P < .01); in addition, eyes gaining one or more visual lines showed greater trefoil reduction and lower residual trefoil than eyes that did not gain (both P < .001). Notably, trefoil metrics did not differ across baseline MRSE strata, although the proportion of eyes with visual line gain decreased with increasing baseline MRSE.

CONCLUSIONS

Ray-tracing-guided LASIK showed favorable safety, efficacy, predictability, and accuracy. Effective trefoil correction with low residual trefoil may be associated with visual line gain, and this association appears to be unaffected by the baseline MRSE distribution.