2.3 Screening process, data extraction
For each eligible study, two independent reviewers (XKL and YJY) independently used EndNote X9 (Clarivate Analytics, Philadelphia, PA, USA) to screen titles and abstracts based on the inclusion and exclusion criteria, and any discrepancies were resolved by discussion with a third reviewer (NS) when necessary. We extracted the data including the baseline on included study characteristics (register number/trial name, year of publication, country or countries, funding, duration), population (disease, sample size by number of eyes, patient demographics), intervention description (route of administration, dose) and outcome (IOP). For IOP, the mean and standard deviation after intervention of each study were extracted.
Quality assessment, the certainty of evidence
Two independent reviewers (XKL and YJY) independently used ROB 2 by RevMan version 6.1 to independently assess the risk of bias of all included studies,14 and the discrepancies were resolved by discussion with a third reviewer (NS) when necessary. The tool is used to determine the risk of bias in randomized trials, including five types of bias risk: risk of bias arising from the randomization process; risk of bias due to deviations from the intended interventions; risk of bias due to missing outcome data; risk of bias in measurement of the outcome; and risk of bias in selection of the reported result. Each risk of bias evaluation dimension had three classifications: low risk of bias, some concerns, or high risk of bias.