Adherence to World Glaucoma Association Guidelines for Surgical Trials in the Era of Microinvasive Glaucoma Surgeries

Purpose To determine how well microinvasive glaucoma surgical (MIGS) trials conform to the World Glaucoma Association (WGA) guidelines. Lack of well-designed MIGS studies hinders meaningful evaluation of these technologies. Design Cross-sectional literature survey. Methods Using a predefined search strategy, the following databases were searched for comparative trials involving MIGS in the English peer-reviewed literature from January 1, 2000, through June 21, 2018: Medline, EMBASE, BIOSIS, Cochrane, and Web of Science. From the WGA guidelines, 53 outcomes were selected for evaluation: methodology (n = 31), definition of success (n = 7), ethics (n = 10), postoperative complications (n = 1), economic evaluation (n = 1), and statistical reporting (n = 3). Each article was assessed by 2 reviewers; differences were resolved by consensus. Results Twenty-five eligible publications were identified: 10 randomized controlled trials (RCTs) and 15 nonrandomized comparative trials (non-RCTs). The mean follow-up was 19.9±11.6 months (range, 6–48 months). The mean number of outcomes adhering to the WGA guidelines of the 53 evaluated was 24.2±6.1 (45.6% compliance): 28.0±6.2 (52.8%) and 21.6±4.7 (40.8%) for RCTs and non-RCTs, respectively ( P  = 0.01). Mean percent compliance for each subsection were: methodology, 48.8%; definition of success, 21.1%; ethics, 55.6%; postoperative complications, 88%; economic evaluation, 0%; and statistical reporting, 37.3%. In 16 studies (64%), at least 1 author reported an association with the industry. Thirty-two percent of studies reported an author being a shareholder. Twenty-four percent of studies had an industry employee author. The primary intraocular pressure (IOP) end point was defined as both an upper limit and percentage reduction in only 4 studies (16%; 1 RCT, 3 non-RCTs). An IOP-based survival curve was provided in 7 studies (28%; none of the RCTs). Two studies (8%) included an IOP scatterplot. Twelve studies (48%) reported 95% confidence intervals. Only 4 studies (16%) used the mean of 3 diurnal IOP readings as the baseline IOP. Conclusions Published comparative MIGS trials show low adherence (45.6%) to the WGA guidelines. Development of standardized methodology and outcomes could enhance interpretation and transparency of study results and facilitate comparisons between trials. Authors and journals should be encouraged to follow the WGA guidelines.