Methodological And Reporting Quality Of Systematic Reviews Comparing Small-Incision Lenticule Extraction (Smile) And Laser-Assisted Keratomileusis (Lasik): An Overview And Cross-Sectional Meta-Research Study

Systematic reviews (SR) are perceived to represent the highest level of evidence; however, misleading interpretations may result if the source of the evidence has methodological issues. Since the introduction of the small-incision lenticule extraction (SMILE) in refractive surgery, several SR have been published aiming to evaluate its comparative efficacy and safety with laser-assisted keratomileusis (LASIK). We aimed to systematically assess the methodological and reporting quality of SR comparing SMILE and LASIK (with or without femtosecond laser), and to stablish the certainty of meta-evidence published on these techniques.

Instituto Universitario Fernández-Vega, Oviedo, Spain

We searched MEDLINE/Pubmed, Scopus, Web of Science, Cochrante Library and Grey literature up to January 2024. Hand-searching was performed on complementary resources as topic-related journals and reference lists. Systematic reviews with or without meta-analyses and those with network meta-analyses were included. We assessed the methodological quality by using the AMSTAR-2 (A MeaSurement Tool to Assess systematic Reviews) tool and the reporting quality by applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. The eligibility of the studies and data assessment were performed by two reviewers independently and disagreements were resolved by discussion. The GRADE approach was used as well.

A total of 22 SR met the eligibility criteria. Most of them (16, 73%) were performed in China. The AMSTAR-2 tool showed that half of SR to have critically low and the other half, low quality, showing that they may not provide an accurate and comprehensive summary of the available evidence and should be taking with cautions. Only two (9%) SR had a registered protocol and the majority had flaws in implementing an exhaustive literature search strategy. None of the included SR reported all the 42 items of the PRISMA 2020 checklist. There is low to critically low certainty of evidence after GRADE appraisal.  

The evidence yielded on SR comparing SMILE and LASIK presented methodological and reporting flaws in critical domains. Research institutions and universities should encourage and train authors to conduct and report higher quality studies to provide better evidence-based medicine.