Hernández‐Da Mota 2010.

Methods	Prospective, randomised, open‐label study Country: Mexico
Participants	Number: 40 Age: Mean 55.7 (both groups) Sex: Not given Inclusion criteria: Presence of advanced PDR Presence of TRD threatening the macula HbA1c < 7 Exclusion criteria: Macular involvement of retinal detachment Iris rubeosis Cataract ‐ when precluding proper evaluation of the fundus No perception of light vision Macular ischaemia
Interventions	Intervention: IVB (1.25 mg/0.05 ml), 48 hours before vitrectomy (n = 20) Comparator: No IVB (n = 20)
Outcomes	Primary outcomes: BCVA Feasibility of surgery (intraoperative bleeding, break formation) Postoperative complications (POVCH, iris rubeosis, and retinal detachment) Follow‐up: 1 week, 3 and 6 months
Notes	No response from authors to correspondence asking for clarification of POVCH definitions. Trial registration number: not reported Date study conducted: not reported Funding: reported none Conflict of interest: reported that there were none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Patients were randomly assigned into two groups"
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants were not masked to treatment group
Blinding of outcome assessment (detection bias) All outcomes	High risk	"For all patients, visual acuity and intraocular pressure were measured and recorded before PPV in a standardized, masked manner" However, not clearly stated whether outcome assessment was always masked and whether other outcomes, such as intraocular bleeding, were masked
Incomplete outcome data (attrition bias) All outcomes	Low risk	Although not directly stated, it is clear from the results that all participants completed the stated follow‐up
Selective reporting (reporting bias)	Low risk	All outcomes were reported