A meta-analysis of visual outcomes and optical quality after small incision lenticule extraction versus implantable collamer lens for myopia

Abstract

Objective To evaluate possible differences in visual outcome and optical quality when small incision lenticule extraction (SMILE) versus implantable collamer lens (ICL) is used to correct myopia. Methods PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched up to August 2021 to identify relevant studies. The PRISMA guidelines were followed. Primary outcomes were postoperative efficacy, safety, and predictability at the end of follow-up. Secondary outcomes were changes in modulation transfer function cutoff frequency (MTF cut−off), objective scatter index (OSI) values, total higher-order aberrations (HOAs), spherical aberrations, and coma aberrations. Results Seven studies with a total of 1296 eyes (SMILE: 731 eyes; TECXL: 565 eyes) were included. The ICL group had a better MTF cut−off ( P = 0.007) and less change in the proportion of HOAs ( P < 0.001), spherical aberrations ( P = 0.009), and coma ( P = 0.006) than the SMILE group. For the other outcomes, there were no statistically significant differences. Conclusions SMILE and ICL implantation are comparable in efficacy, safety, and predictability for correcting myopia. Larger studies with longer follow-up times are warranted to provide a better understanding of the benefits of SMILE and ICL implantation.