Clinical outcomes and higher order aberrations of wavefront‐guided LASIK versus SMILE for correction of myopia: A systemic review and meta‐analysis

Abstract To systematically evaluate the clinical effect of wavefront‐guided laser in situ keratomileusis (WFG‐LASIK) and small incision lenticule extraction (SMILE) in terms of refractive errors and high‐order aberrations. A systematic literature search of PubMed, EMBASE, the Cochrane Library, Web of Science and China National Knowledge Internet was performed to identify studies evaluating the clinical outcomes of SMILE and WFG‐LASIK ended in May 2022. Meta‐analyses were performed according to the PRISMA guidelines. The risk of bias of the RCTs was evaluated using the Cochrane Handbook criteria, and the quality of the non‐randomised controlled studies was assessed using the Newcastle‐Ottawa Scale. In total, 1385 eyes (SMILE group, 750 eyes; WFG‐LASIK group, 635 eyes) from 12 studies were included. The meta‐analysis demonstrated that spherical aberration was smaller in the SMILE group than in the WFG‐LASIK group (standardised mean difference [SMD]: −0.34, 95% confidence interval [CI]: −0.47, −0.22; p < 0.00001), and that the postoperative values of vertical coma (SMD: 0.83; 95% CI: 0.63, 1.03; p < 0.00001) and trefoil (SMD: 0.37; 95% CI: 0.02, 0.72; p = 0.04) were higher in the SMILE group compared to the WFG LASIK group. There were no significant differences in the clinical outcomes and the values of induced total higher order aberrations between the WFG‐LASIK and SMILE groups (SMD: 0.05; 95% CI: −0.09, 0.19; p = 0.47). Both SMILE and WFG‐LASIK were found to be safe, effective, and predictable. SMILE may induce more vertical coma and trefoil, whereas WFG LASIK may induce more spherical aberrations, but no significant differences were found in the total higher order aberrations between SMILE and WFG‐LASIK.