Cillino 2008.

Methods	Study design: parallel‐group randomized controlled trial Number randomized: 60 eyes of 60 participants; 15 eyes of 15 participants in each of the 4 groups Exclusions after randomization: none reported Losses to follow‐up: none reported Unit of analysis: individual (1 eye per participant) Number analyzed: 60 participants total; 15 participants in each of the 4 groups How were missing data handled?: no missing data Power calculation: a power of 90% or greater to detect at least a 3 mm Hg IOP difference among groups
Participants	Country: Italy Mean age: 68 years; 65.3 years for trabeculectomy + MMC + E‐PTFE group; 68.1 years for trabeculectomy + MMC group; 67.2 years for trabeculectomy + E‐PTFE group; 71.1 years for trabeculectomy group; Gender: 24/45 (53%) men and 21/45 (47%) women; 6/15 (40%) men and 9/15 (60%) women in trabeculectomy + MMC + E‐PTFE; 9/15 (60%) men and 6/15 (40%) women in trabeculectomy + MMC; 7/15 (47%) men and 8/15 (53%) women in trabeculectomy + E‐PTFE; 8/15 (53%) men and 7/15 (47%) women in trabeculectomy Inclusion criteria: “age 18 or older, diagnosis of POAG or pseudoexfoliative glaucoma (PEXG), and inadequate IOP control (IOP > 21 mm Hg) or progressive visual field deterioration on maximum‐tolerated medical therapy, availability, willingness and sufficient cognitive awareness to comply with examination procedures” Exclusion criteria: “concurrent participation during the last 30 days in any other clinical trial, use of systemic or ocular medications that may affect vision, acute or chronic disease or illness that would increase the operative risk or confound the outcomes of the study (e.g. immunodeficiency, connective tissue disease, diabetes, etc.), uncontrolled systemic or ocular disease other than glaucoma, clinically significant cataract where combined surgery was indicated, history of ocular trauma or prior ocular surgery.” Equivalence of baseline characteristics: yes
Interventions	Intervention 1: trabeculectomy + MMC + E‐PTFE (GORE PRECLUDE®) Intervention 2: trabeculectomy + MMC Intervention 3: trabeculectomy + E‐PTFE (GORE PRECLUDE®) Intervention 4: trabeculectomy Length of follow‐up: Planned: 24 months Actual: 24 months
Outcomes	Primary and secondary outcomes not distinguished Outcomes, as reported: IOP, complete success (with medication ≤ 21 and without medication 17 mm Hg), complications, number of antiglaucoma medications, and visual field testing by Humphrey visual field Intervals at which outcomes assessed: 24 hours, 7 days, 2 weeks, 3 weeks, and 1, 2, 3, 6, 12, 18, and 24 months after surgery
Notes	Publication type: published article Funding sources: not reported Disclosures of interest: not reported Trial registry: not registered Study period: September 2003 to August 2004 Subgroup analyses: none reported Publication language: English Authors not contacted
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	“Randomization was determined just before surgery. Sixty participants – 15 for each surgical technique – were randomly assigned based on a surgical chart number to undergo a trabeculectomy (T) (which served as surgical control group), a trabeculectomy with mitomycin‐C (TMMC), a trabeculectomy with GORE PRECLUDE pericardial implant (TG) or a trabeculectomy with mitomycin‐C and GORE PRECLUDE pericardial implant (TGMMC).” The method of sequence generation was not done completely randomly, thus we assessed it at high risk
Allocation concealment (selection bias)	Low risk	“Randomization was determined just before surgery by sealed‐envelope technique.”
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	It is not possible to mask outcome assessors, as devices can be easily seen during eye examination
Incomplete outcome data (attrition bias) All outcomes	Low risk	“All participants completed the 24 month follow‐up period.”
Selective reporting (reporting bias)	Unclear risk	Protocol was not available. In the Methods section, the study mentioned testing of visual field by Humphrey visual field, however, the Result section did not report this outcome
Other bias	Unclear risk	Did not report source of funding or conflict of interest