El‐Batarny 2008.

Methods	Study design: prospective, randomised trial of intravitreal bevacizumab as an adjunctive treatment before diabetic vitrectomy Unit of randomisation: participant Unit of analyses: eye/participant Follow‐up: 1 day, 1 week, 2 weeks, 1 month after surgery and monthly up to the end of the follow‐up (mean 12 months; range 7‐18 months)
Participants	Country: Sultanate of Oman Setting: Magrabi Eye and Ear Hospital, Muscat, Sultanate of Oman Number of participants: 30 (30 eyes) Exclusions post‐randomisation: 0 Losses to follow‐up: 0 Age (mean (SD)): 44 (11) years in bevacizumab plus vitrectomy group, 46 (12) years in vitrectomy alone group Gender: not reported Inclusion criteria: people with indications for vitrectomia for complications of PDR existed such as TRD involving or treating the macula, not resolving VH, pre‐retinal subhyaloid bleeding Exclusion criteria: not reported
Interventions	Treatment: intravitreal injection of bevacizumab 1.25 mg/0.05 mL, 5‐7 days before vitrectomy Control: vitrectomy alone Duration: only 1 dose
Outcomes	Primary: feasibility of the surgery and postoperative complications Secondary: visual acuity at 6 months of follow‐up, any bevacizumab‐related adverse event
Notes	Funding: not reported Trial registration: not reported Date conducted: not reported Conflict of interest: none reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: not described
Allocation concealment (selection bias)	Unclear risk	Comment: not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: not described
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: not described
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: there were 0 losses
Selective reporting (reporting bias)	Low risk	Comment: the results of the variables were described in the methods section