Control-matched comparison of refractive and visual outcomes between small incision lenticule extraction and femtosecond laser-assisted LASIK

Abstract

PurposeThis retrospective case-matched study aimed to compare visual and refractive outcomes between small incision lenticule extraction (SMILE) and LASIK.Patients and methodsPatients who underwent SMILE (34 eyes of 23 patients) or LASIK (34 eyes of 24 patients) were enrolled and matched according to preoperative manifest refractive spherical equivalents. The mean preoperative manifest refractive spherical equivalent was −4.69±0.6 and −4.67±0.64 D in the SMILE and LASIK groups, respectively. The safety, efficacy, and predictability were compared 3 months after surgery. Changes in corneal refractive power from the center to peripheral points and their maintenance ratios were analyzed and compared between the two groups.ResultsIn the SMILE and LASIK groups, 82.4% and 85.3% of patients, respectively, achieved 20/13 or better uncorrected distance visual acuity (p=1.00). There were no eyes that lost two or more lines of corrected distance visual acuity in either group. The maintenance ratios of corneal refractive power changes at the peripheral points in the SMILE group were significantly higher than those in the LASIK group (p<0.05).ConclusionBoth groups achieved similar high efficacy and safety. SMILE surgery resulted in higher refractive power correction in the peripheral cornea than LASIK surgery.

Comparison of Corneal Optical Quality After SMILE, Wavefront-Optimized LASIK and Topography-Guided LASIK for Myopia and Myopic Astigmatism

“…The current study found no significant differences in postoperative UDVA or CDVA among SMILE, WFO, and TCAT groups, indicating that the three procedures were comparably effective and safe. The majority of previous studies demonstrated the similar results ( 2 , 8 – 15 , 17 – 19 ). A randomized, paired-eye study found that SMILE achieved similar results to WFO LASIK in terms of efficacy index (0.97 ± 0.20 vs. 0.99 ± 0.20; P = 0.56), UDVA of 20/40 or better (100 vs. 100%; P = 1.0), and UDVA of 20/20 or better (84 vs. 87%; P = 0.63) ( 9 ).…”

“…There are some discussions on which of the two surgical methods is better for vision and visual quality. Some studies have found no significant difference between the two procedures ( 2 , 8 – 12 ), whereas other studies have indicated that either SMILE or FS-LASIK should be preferred in terms of refractive results or higher-order aberrations ( 13 – 19 ).…”

Comparison of Visual, Refractive and Ocular Surface Outcomes Between Small Incision Lenticule Extraction and Laser-Assisted In Situ Keratomileusis for Myopia and Myopic Astigmatism

“…In a 2018 Japanese retrospective case–control study on patients with moderate myopia and myopic astigmatism, Kataoka et al compared 3-month postoperative visual outcomes between 34 eyes of 23 patients treated with SMILE (mean preoperative manifest refractive sphere: −4.52 ± 0.54 D; mean preoperative manifest refractive cylinder: −0.33 ± 0.38 D) and 34 eyes of 24 patients treated with LASIK (−4.45 ± 0.61 D; −0.45 ± 0.44 D). The authors found no significant differences in postoperative uncorrected distance visual acuity (UDVA) (82.4% and 85.3% of patients with 20/13 or better UDVA for SMILE and LASIK, respectively) or corrected distance visual acuity (CDVA) (97.06% and 100% of patients with 20/13 or better CDVA for SMILE and LASIK, respectively) between groups, showing that both procedures were highly effective [7]. A retrospective study including 68 SMILE-treated eyes of 35 patients in the United States with myopia or myopic astigmatism (preoperative manifest refractive sphere and cylinder ranged from −7.50 to −2.75 D and −0.75 to 0.00 D, respectively) showed that, although visual outcomes for SMILE (74% of eyes with 20/20 UDVA or better) were superior to first-generation LASIK [SVS Apex Plus, VISX STAR S2, Nidek EC-5000 (2000)] from 1999 to 2000 (51%), they were inferior to the latest generation (Nidek EC-5000 (2013), Alcon Contoura, VISX iDesign) from 2013 to 2016 (89%) [8].…”

“…Although SMILE and LASIK have shown comparable visual outcomes, there are a number of potential advantages with the SMILE technique. One study suggested that SMILE has greater refractive power correction efficiency than LASIK in the peripheral cornea [7]. Maintenance ratios at the eighth to tenth analysis points on the cornea in the SMILE group (8th, 83.71% ± 8.44%; 9th, 74.03% ± 7.9%; and 10th, 63.25% ± 8.06%) were significantly higher than those in the LASIK group (8th, 79.86% ± 5.83%; 9th, 70.44% ± 6.11%; and 10th, 57.7% ± 6.37%).…”

Vector analysis of high astigmatism (≥ 2.0 diopters) correction after small-incision lenticule extraction with stringent head positioning and femtosecond laser-assisted laser in situ keratomileusis with compensation of cyclotorsion

“…Thus, dry eye and flap-related complications are reduced as compared to FS-LASIK. Many studies have shown that visual and refractive outcomes, safety, efficacy, and predictability are comparable in SMILE and FS-LASIK [ 3 , 4 ]. However, the precision of astigmatism correction in the SMILE platform is uncertain because of the lack of cyclotorsion control.…”