De Jong 2009.

Study characteristics
Methods	Study design: parallel‐group randomized controlled trial (2 participants both eyes included) Number randomized: 80 eyes of 78 participants total; 40 eyes in each group Exclusions after randomization: none reported Losses to follow‐up: 5 eyes total at 1 year; 3 eyes in trabeculectomy + MMC + Ex‐PRESS group; 2 eyes in trabeculectomy + MMC group Unit of analysis: eye Number analyzed: 75 eyes total; 37 eyes in trabeculectomy + MMC + Ex‐PRESS group; 38 eyes in trabeculectomy + MMC group How were missing data handled? 5 eyes with missing data excluded from analysis Power calculation: a power of 80% to detect 32% between‐group difference in IOP
Participants	Country: the Netherlands Mean age: 66 years; 62.3 years for trabeculectomy + MMC + Ex‐PRESS group 68.9 years for trabeculectomy + MMC group Gender: 46/80 (58%) men and 34/80 (42%) women 19/40 (48%) men and 21/40 (52%) women in trabeculectomy + MMC + Ex‐PRESS group; 27/40 (68%) men and 13/40 (32%) women in trabeculectomy + MMC group Inclusion criteria: aged > 18 years with a diagnosis of OAG that could not be controlled with maximal‐tolerated medical therapy Exclusion criteria: any other ocular disease or previous ocular surgery other than cataract extraction Equivalence of baseline characteristics: not reported
Interventions	Intervention 1: trabeculectomy + Ex‐PRESS Intervention 2: trabeculectomy Length of follow‐up Planned: 5 years Actual: mean 262 weeks for Ex‐PRESS group and 266 weeks for trabeculectomy group
Outcomes	Primary outcome, as defined: complete success (final IOP > 4 mmHg and ≤ 18 mmHg without antiglaucoma medication) and overall success (final IOP > 4 mmHg and ≤ 18 mmHg with or without medications) Secondary outcomes, as defined: IOP, postoperative medication use, surgical failure (IOP > 18 mmHg or the requirement for further glaucoma surgery), stringent target (final IOP > 4 mmHg and ≤ 15 mmHg), complications, and visual acuity Intervals at which outcomes assessed: 1 day; 1 week; 1, 3, and 6 months; and 1, 2, 3, 4, and 5 years after surgery Length of follow‐up Planned: not reported Actual: 60‐month follow‐up
Notes	Publication type: published article Funding sources: Alcon Management SA, Geneva, Switzerland Disclosures of interest: (quote) "L. de J. has no proprietary interest in any of the products mentioned here." Trial registry: not registered Study period: October 2003 to November 2004 Subgroup analyses: none reported Publication language: English Authors contacted to retrieve number of participants lost to follow‐up at 2–5 years, but no response received
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quotes: "The participants were assigned randomly to receive either Ex‐PRESS implantation under a scleral flap (Group A), or trabeculectomy (Group B) in the study eye, according to a computer‐generated randomization list." "Randomization was determined before surgery according to a block randomization sequence prepared by SAS (version 9.1; SAS Institute Inc., Cary, NC, USA)."
Allocation concealment (selection bias)	Unclear risk	Allocation concealment was not reported.
Masking of participants and personnel (performance bias)	Low risk	Because trabeculectomy is a surgical procedure with informed consent, masking of the participants and personnel becomes impossible. However, given that a strict and standardized surgical protocol was followed and differences in the surgical protocol of the 2 groups were minimized, the risk of performance bias is comparably low for a surgical procedure.
Masking of outcome assessment (detection bias)	High risk	Quote: "Secondly, the evaluator was not blinded to the procedure used in each case; however, it is difficult to carry out truly blinded evaluation as the type of surgery used is usually visible to the assessor." Comment: but how they controlled the risk was not specified.
Incomplete outcome data (attrition bias) All outcomes	Low risk	There are 2 articles related to this study, as reported in 2009, the number analyzed was 40 eyes per treatment group (no loss to follow‐up); however, as reported in 2011, the number analyzed was 38 eyes per treatment group.
Selective reporting (reporting bias)	Low risk	Protocol was not available. All defined outcomes were reported.
Other bias	Unclear risk	Total industry support but no other source of potential bias identified. Quote: "There were no significant differences between the two groups except for age; the Ex‐PRESS group (Group A) included significantly younger patients compared with the trabeculectomy group (Group B)." Comment: age‐adjusted values are reported in de Jong 2011 and do not significantly change the results.