For each included study, information will be extracted on the type of included study (systematic review, systematic review and meta-analysis, meta-analysis, or network meta-analysis); publication date; number of databases sourced and searched; last literature search; type of included primary studies (randomized controlled trials, observational studies, or both); country/countries of origin of studies included in each review; number of primary studies in each review; source of financial support (if any); participants’ characteristics (age range); total sample size (or range of sizes of primary studies); type of treatment (optical or pharmaceutical) and dose when applicable; type of control (optical, pharmaceutical, or placebo) and dose when applicable; follow-up period; outcomes that are relevant to our overview question; results; major conclusions; instrument used to appraise the primary studies and the rating of their quality; metric used and effect size (for meta-analyses); p-value (for meta-analyses); confidence intervals (for meta-analyses); additional analyses (e.g. subgroup analysis, meta-regression, sensitivity analysis, for meta-analyses); and handling of heterogeneity (fixed/random effects model, funnel plot, for meta-analyses).