Baker 2021.

Study characteristics
Methods	Study design: multicenter, parallel‐group, randomized controlled trial Country: the US, France, Italy, the Netherlands, Spain, the UK Number randomized: 527 eyes of 527 participants total; 395 for PreserFlo MicroShunt + MMC and 132 for trabeculectomy + MMC Exclusions after randomization: none reported Losses to follow‐up: 21 for total; 14 for PreserFlo MicroShunt + MMC and 7 for trabeculectomy + MMC Unit of analysis: eye Number analyzed: 527 eyes of 527 participants total; 395 for PreserFlo MicroShunt + MMC and 132 for trabeculectomy + MMC How were missing data handled? imputed Power calculation: (quote) "sample size calculations were based on a Z‐test with normal distribution approximation and assuming an annual dropout rate of 6%."
Participants	Mean age: none reported for overall; 66.4 (SD 9.3) years for PreserFlo MicroShunt + MMC group; 67.8 (SD 9.3) years for trabeculectomy + MMC group Gender 181/395 (45.8%) men and 214/395 (54.2%) women in PreserFlo MicroShunt + MMC group; 59/132 (44.7%) men and 73/132 (55.3%) women in trabeculectomy + MMC group Inclusion criteria: aged 40–85 years with mild‐to‐severe POAG inadequately controlled on maximum tolerated medical therapy, with IOP > 15 mmHg and < 40 mmHg and a visual field mean deviation of ≤ −3.00 dB Exclusion criteria: secondary OAG such as post‐trauma, pseudoexfoliative, or pigment dispersion (pigmentary glaucoma); ACG; aphakia; vision level of no light perception; previous incisional ophthalmic surgery involving the conjunctiva; prior clear corneal cataract, angle, or trabecular meshwork surgery conducted within the past 6 months; ocular steroid use in the planned study eye or systemic steroid use any time within 3 months of the procedure; BCVA < 20/80 in the non‐study eye; and laser surgery within 90 days of enrollment Equivalence of baseline characteristics: yes, apart from a higher proportion of Black/African American people (18.0% in the PreserFlo MicroShunt group vs 8.3% in the trabeculectomy group; P < 0.01).
Interventions	Intervention 1: PreserFlo MicroShunt + MMC Intervention 2: trabeculectomy + MMC Length of follow‐up Planned: 1 years Actual: 1 years
Outcomes	Primary outcomes, as defined: ≥ 20% reduction in mean diurnal IOP from baseline at 1 year follow‐up visit without increasing the number of glaucoma medications. Secondary outcomes, as defined: mean diurnal IOP change from baseline at 1 year; requirement for postoperative intervention by 1 year; number of glaucoma medications per participant at each follow‐up visit; incidence of adverse events; presence of cataract in phakic eyes; time for postoperative BCVA to return to baseline; change in endothelial cell density Intervals at which outcomes assessed: 1 day; 1 and 4 weeks; 3, 6, 12, 18, and 24 months
Notes	Publication type: published article Funding sources: InnFocus Inc, a Santen Pharmaceutical Co Ltd Company and Santen Inc (quote: "the sponsor participated in the design and conduct of the study, data collection, and management. This analysis was also sponsored by Santen Inc., which participated in the data analysis, interpretation of the data, and preparation, review, and approval of the manuscript"). Disclosures of interest: "N.D.B.: Consultant/Advisor: Molteno Ophthalmic, Santen; Investigator: Santen. H.S.B.: Consultant/Advisor: Santen; Lecture fees Aerie, Bausch & Lomb. M.R.M.: Consultant/Advisor: Aerie, Alcon, Allergan, Qura, Santen; Lecture fees: Aerie, Alcon, Allergan, Bausch & Lomb, Iridex, MedEdicus, Novartis; Grant support: Aerie, Alcon, Allergan, Bausch & Lomb, Glaukos, InnFocus, Iridex, Santen; Equity/Owner: Qura. M.C.S.: Grant support Allergan, Glaukos, Ivantis, Santen. S.D.V.: Consultant/Advisor: Aerie, Alcon, Allergan, Bausch & Lomb, Carl Zeiss Meditec, Glaukos, Iridex, iSTAR Medical, Ivantis, New World Medical, Sight Sciences, Volk Optical; Grant support: Aerie, Alcon, Allergan, Bausch & Lomb, Carl Zeiss Meditec, Glaukos, Ivantis, RxSight, Santen, Sight Sciences; Equity/Owner: Alphaeon, Ivantis, O3 Optix; Patents/Royalty: Iridex, Volk Optical. A.K.K.: Consultant/Advisor: Gore Inc, Ivantis, Reliance/Haag‐Streit; Lecture fees: Aerie, Ivantis; Grant support: Glaukos, InnFocus, Santen. B.E.F.: Consultant/Advisor: Alcon, Bausch & Lomb, Eyenovia, Glaukos, InnFocus, iSTAR Medical, Ivantis, New World Medical, l, Sight Sciences; Grant support: Eyenovia, Glaukos, InnFocus, iSTAR Medical, Ivantis, Santen, Sight Sciences. D.S.G.: Consultant/Advisor: Allergan, MicroOptx, New World Medical, Reichert Instruments, Santen; Lecture fees: Aerie, Allergan, Bausch & Lomb, New World Medical, Reichert Instruments; Grant support: Allergan. N.G.S.: Funding: NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, and UCL Institute of Ophthalmology. The sponsor or funding organization had no role in the design or conduct of this research. The views expressed are those of the authors and not necessarily those of the NHS, NIHR, or UK Department of Health. J.F.P.: Consultant/Advisor: Aerie, Allergan, Cornea Gen, Glaukos, New World Medical, Santen; Grant support: Allergan." Trial registry: NCT01881425 Study period: December 2015 to November 2017 Subgroup analyses: (quote) "Prespecified subgroup analyses in patients with baseline mean diurnal IOP<18, 18–20, and >21 mmHg were conducted." Publication language: English
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Study authors clearly reported that randomization was performed in a 3:1 ratio, which was stratified by investigational site and within site by lens status. The baseline characteristics in both groups were similar, suggesting effective randomization.
Allocation concealment (selection bias)	Low risk	Allocation concealment was performed using envelopes containing the randomization assignments.
Masking of participants and personnel (performance bias)	Low risk	Participants were masked to the assignment, and it is unlikely that they were aware of their group assignment after the operation given the similar possible complications.
Masking of outcome assessment (detection bias)	High risk	Outcome assessors were not masked to the participant's group assignment. The study authors did not explicitly specify the method used to measure IOP. However, as some methods of IOP measurement, e.g. using Goldmann applanation, could be subjective, it is likely that the unmasking of outcome assessors would affect the outcome.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Only 3–5% of each group were lost to follow‐up. This missingness was unlikely related to worsening participants' health status due to device or procedure.
Selective reporting (reporting bias)	Low risk	The trial was analyzed according to the prespecified plan in terms of outcome measurements (e.g. definition, scales, and time points) within each outcome.
Other bias	High risk	This study was sponsored by the InnFocus company and many of the authors had industrial support.