Comparison of Small Incision Lenticule Extraction (SMILE) and Femtosecond Laser In-Situ Keratomileusis (F-LASIK) for the Correction of Myopia and Astigmatism: 1-Year Clinical Outcome
Marianne Roque, MD, Ruben Lim Bon Siong, MD, Irwin Cua, MD, Bernardo Joaquin P. Tuano, MD, and Winston Villar, MD
To compare the efficacy, refractive predictability, stability and safety of Small Incision Lenticule Extraction (SMILE) and Femtosecond Laser In-Situ Keratomileusis (F-LASIK) for the correction of myopia and
This study was approved by the Institutional Review Committee of the St. Luke’s Medical Center. A retrospective chart review was conducted at the Vision Laser Center of the St. Luke’s Medical Center-Global City. All patients that underwent SMILE from January 2014 to July 2014, with adequate follow-up at 1 day, 1 week, 1 month, 3 months and 1 year, were included in the study. Age-matched and refraction-matched patients, who underwent F-LASIK from January 2012 to April 2014, were chosen as comparators. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), attempted refraction versus achieved refraction and adverse events at 1 day, 1 week, 1 month, 3 months and 1 year were compared postoperatively in both groups. Primary outcome measures were efficacy expressed as the percentage of eyes achieving UCVA of 20/25 or better during the postoperative follow-up, refractive predictability, safety and stability.
Thirty-five eyes of 18 patients who underwent SMILE and 38 eyes of 19 patients who underwent FLASIK were included in the study. The mean preoperative spherical equivalent of both groups had no statistical difference, with -3.84 ± 1.31 D and -4.07 ± 1.39 D for SMILE and F-LASIK, respectively (p=0.801). At 1 week postoperatively, 51% and 97% achieved UCVA of 20/25 or better in the SMILE and F-LASIK groups. At 3 months, 97% had 20/25 vision or better for the SMILE group, while 100% had 20/25 vision or better for the F-LASIK group. At 1 year, both groups achieved 100% 20/25 or better vision. Three percent lost one line of
BCVA in both groups at 1 year. Mean spherical equivalent (SE) between groups at 1 year showed no statistically significant difference (p=0.21), with 0.05 ± 0.18 D in the SMILE group and -0.1 ± 0.15 D in the F-LASIK group. No significant change in mean SE was observed within groups from 1 day to 1 year post op, p=0.166 for SMILE and p=0.226 for F-LASIK. At 1 year, 100% of the SMILE and F-LASIK groups were within ± 0.5 D of target refraction. No adverse events were noted in either group.
SMILE was comparable to F-LASIK in terms of visual outcomes (efficacy, refractive predictability,
stability) and safety for the treatment of myopia and astigmatism. However, a slight delay in visual improvement during the first week was observed in the SMILE group.
Keywords: small incision lenticule extraction, femtosecond LASIK, myopia, astigmatism, SMILE, ReLex