Topography-Guided LASIK Versus Small Incision Lenticule Extraction (SMILE) for Myopia and Myopic Astigmatism: A Randomized, Prospective, Contralateral Eye Study

PURPOSE: To compare safety and efficacy of topography-guided LASIK and contralateral eye SMILE for myopia and myopic astigmatism correction. METHODS: This prospective, randomized contralateral eye study included 44 eyes of 22 patients with bilateral myopia or myopic astigmatism. Treated eyes were divided into two groups: 22 eyes were treated with topography-guided LASIK and the fellow eye of each patient was treated with SMILE. The following parameters were evaluated preoperatively and up to 3 months postoperatively: uncorrected distance vision acuity (UDVA), corrected distance vision acuity (CDVA), refractive error, corneal keratometry, contrast sensitivity, and Objective Scatter Index. RESULTS: At 3 months, 86.4% of the LASIK group and 68.2% of the SMILE group had UDVA of 20/20 ( P < .002) and 59.1% and 31.8%, respectively, had UDVA of 20/16 ( P < .002). Spherical equivalent refraction (±0.50 D) was 95.5% for the LASIK group and 77.3% for the SMILE group ( P < .002). Residual refraction cylinder (≤ 0.25 D) was 81.8% for the LASIK group and 50% for the SMILE group ( P < .001). Contrast sensitivity (6 cycles/degree) was 7.2 ± 1.01 in the LASIK group and 6.20 ± 1.52 in the SMILE group. Objective Scatter Index measurements at 3 months were 1.35 in the LASIK group and 1.42 in the SMILE group. CONCLUSIONS: Topography-guided LASIK was superior in all visual performance parameters studied, both subjective and objective. The main difference between the two techniques likely derives from the eye tracking, cyclorotation compensation, and active centration control in the LASIK technology studied in contrast to the current technology available with SMILE-like procedures. This difference appears to affect refractive and visual aberration performance outcomes. [ J Refract Surg. 2017;33(5):306–312.]