Laser-based refractive surgery techniques to treat myopia in adults. An overview of systematic reviews and meta-analyses

Review question / Objective: Study design -The units of analysis were systematic reviews with or without metaanalyses, and those with network meta-analysis, if any.All of them were based on randomized controlled trials (RCTs) or non-randomized studies of interventions (NRSI) in adults (≥ 18 years of age).On the other hand, narrative reviews without systematic electronic searches and evidence appraisals were excluded.For the present overview, a systematic review was defined as such based on the following methodological criteria: -It must be a secondary analysis of primary studies, consulting at least two main databases and critically assessing the methodological quality of the included studies.-It must have a clearly formulated question or aim.-It must use systematic and explicit methods to identify, select, extract and analyze data from the studies.-When two SRs involving the same topic and the same authors are found, the most recent SR is considered.