Authors: David J. Mathew, Bryon R. McKay, Alfred Basilious, Avner Belkin, Graham E. Trope, Yvonne M. Buys.
Author Disclosure Block: D.J. Mathew: None. B.R. McKay: None. A. Basilious: None. A. Belkin: None. G.E. Trope: None. Y.M. Buys: None.

Abstract Body:

Purpose: In March 2009, the World Glaucoma Association (WGA) published guidelines for the design, conduction and reporting of glaucoma surgical trials in order to facilitate meaningful studies and comparisons between studies through standardization of reported outcomes. The goal of this study was to determine how well surgical trials using microinvasive glaucoma surgeries (MIGS) conform to the WGA guidelines.
Study Design: Systematic review
Methods: Using a predefined search strategy, the following databases were searched for comparative trials involving MIGS in the English peer-reviewed literature from 2000 to June 21, 2018: Medline, EMBASE, BIOSIS, Cochrane and Web of Science. From the WGA guidelines, 53 outcomes were selected for evaluation: methodology (31), definition of success (7), ethics (10), postoperative complications (1), economic evaluation (1) and statistical reporting (3). Each article was assessed by two reviewers and differences were resolved by consensus.
Results: Twenty-eight eligible publications were identified; three were longer-term follow-ups from a previous publication, leaving 25 distinct studies. There were 10 randomized controlled trials (RCT) and 15 non-randomized comparative trials (non-RCT). The mean total score out of 53 was 24.2±6.2 (45.7% compliance): 28.1±6.2 (53%) and 21.6±4.7 (40.8%) for RCT and non-RCT, respectively. The mean follow-up was 19.9±11.6 months (range, 6-48). Mean % compliance for each subsection were: methodology 48.9%; 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 one author reported an association with the industry. 32% of studies reported an author being a shareholder. 24% of studies had industry as an author. The primary IOP endpoint was defined as both an upper limit and percentage reduction in only 4 (16%) studies (1 RCT, 3 non-RCT). An IOP-based survival curve was provided in 7 (28%) studies (none of the RCTs). Two studies (8%) had an IOP scatter plot. Twelve studies (48%) reported 95% confidence intervals. The use of Goldmann applanation tonometry for intraocular pressure (IOP) measurement was mentioned in 18 (72%) studies. Only 4 (16%) studies used the mean of three diurnal IOP readings as the baseline IOP.
Conclusions: Published comparative MIGS trials show low adherence (45.7%) to the WGA guidelines. Developing standardized methodology and reporting of results of glaucoma surgical trials could greatly enhance interpretation and transparency of study outcomes and facilitate comparisons between trials. Authors and journals should be encouraged to follow the WGA guidelines.