Wavefront-Guided LASIK Offers Some Benefits SMILE Does Not

Optometrist treating patient in laser surgery room
Male and female optometrist treating patient in laser surgery room
A study shows a faster visual recovery, better low-contrast acuity, and greater improvements in uncorrected acuity.

While both wavefront-guided (WFG) LASIK and small incision lenticule extraction (SMILE) deliver significant improvements in corrected distance visual acuity, researchers have found that the additional benefits of WFG-LASIK include faster visual recovery, better low-contrast visual acuity, and greater improvements in uncorrected visual acuity.

In the years since LASIK debuted, advancements have improved the procedure’s safety, efficacy, and predictability. For example, WFG LASIK is designed to measure and correct lower- and higher-order irregularities for each eye, which may produce fewer induced higher-order aberrations, according to researchers.

Investigators conducted a single-center prospective, randomized study to compare WFG-LASIK with SMILE. The research team enrolled 44 patients (88 eyes) with myopia and low astigmatism. Patients were treated with WFG-LASIK in 1 eye and SMILE in the other eye. Of the group, 37 patients (74 eyes) were treated successfully and completed 12 months of follow-up. 

The findings, published in the American Journal of Ophthalmology, reveal a significantly higher proportion of WFG-LASIK eyes achieved ≥20/20 uncorrected distance visual acuity at 12 months post-procedure than eyes treated with SMILE (94% vs. 83%, P <.05). Specifically, researchers found:

  • No difference between spherical equivalent between the groups (-0.17±0.25 vs. -0.29±0.38, P >.05).
  • No difference in higher-order aberrations, including coma, trefoil, and spherical aberrations (P >.05).
  • A significantly higher proportion of WFG-LASIK eyes demonstrated improved 5% and 25% low-contrast visual acuity compared with SMILE eyes (P <.05).

“Given the significantly increased experience with LASIK and relatively shorter experience with SMILE, these findings are not unexpected. LASIK is a relatively mature technology with a track record spanning decades,” according to the report. “Though this study highlights the superior visual outcomes achieved with LASIK, it is important to note that SMILE achieved good increases in visual acuity also. Perhaps with continued advancements, the differences in visual outcomes between the LASIK and SMILE will be less apparent.”

The limitations of this study include difficulties understanding bilateral effects, such as differences in eye dryness, tear film stability, and eye discomfort. Other limitations include single-surgeon outcomes analysis, the small sample size, and enrolling only patients with myopia and low levels of astigmatism

Disclosure: This research was partially supported by Johnson and Johnson Vision. One of the study’s authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.  


Chiang B, Valerio GS, Manche EE. Prospective, randomized, contralateral eye comparison of wavefront-guided laser in situ keratomileusis (WFG-LASIK) and small incision lenticule extraction (SMILE) refractive surgeries. Am J Ophthalmol. Published online November 14, 2021. doi:10.1016/j.ajo.2021.11.013