Clinical Outcomes of SMILE and FS-LASIK Used to Treat Myopia: A Meta-analysis

PURPOSE: To assess possible differences in clinical outcomes when small-incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK) are used to correct myopia. METHODS: A systematic review and meta-analysis. A systematic literature search was performed using Cochrane Collaboration methodology to identify randomized controlled trials and appropriate comparative studies comparing SMILE and FS-LASIK for myopia. RESULTS: The authors identified 11 studies from a review of 102 articles, involving a total of 1,101 eyes, of which 532 eyes (48.32%) underwent SMILE and 569 eyes (51.68%) underwent FS-LASIK. No significant difference between the two procedures was evident in terms of final refractive spherical equivalent (P = .72), the proportion of eyes losing one or more lines of corrected distance visual acuity after surgery (P = .69), or the proportion of eyes achieving an uncorrected distance visual acuity of 20/20 or better (P = .35) and a refractive spherical equivalent within +/- 1.00 diopter of the target values (P = .70). The tear break-up time was longer in the SMILE group than the FS-LASIK group at 1 (P = .004) and 6 (P = .02) months after surgery. Corneal sensitivity was higher in the SMILE group than in the FS-LASIK group at 1 week (P < .00001) and 1 (P < .0001), 3 (P < .00001), and 6 (P < .003) months after surgery. CONCLUSIONS: SMILE and FS-LASIK were comparable in terms of both safety and efficacy. SMILE may create fewer dry eye symptoms than FS-LASIK. Corneal sensitivity was greater after SMILE than FS-LASIK.