Farahvash 2011.

Methods	Randomised, single‐masked (surgeon), controlled trial Country: Iran
Participants	Number: 35 Age: Mean (range) 58.5 (37 to 73) Sex: M/F. 18/17 Inclusion criteria: Vitreous haemorrhage > 1 month in a participant with no history of panretinal photocoagulation Non‐clearing vitreous haemorrhage in a participant with complete panretinal photocoagulation Vitreous haemorrhage with neovascularisation of the iris Vitreous haemorrhage with glaucoma Vitreous haemorrhage with retinal detachment Exclusion criteria: Vitrectomy or any intraocular injection in the study eye History of IVB in either eye Previous myocardial infarction or thromboembolic event Uncontrolled hypertension Use of anticoagulation (except aspirin, which was discontinued 1 week before injection) or coagulation abnormalities
Interventions	Intervention: IVB (1.25 mg) 7 days before surgery (n = 18) Comparator: No IVB (n = 17)
Outcomes	Primary outcomes: Severity of intraoperative bleeding and break formation Secondary outcomes Visual acuity at month 3 postsurgery Complications of surgery: retinal detachment, neovascular glaucoma Early and late postoperative vitreous haemorrhage Follow‐up: 1 day, 1 week, every 3 months (minimum follow‐up 3 months)
Notes	We contacted the authors to further discuss the severity of POVCH in each arm of the study. Although no formal grading scale was used to assess the POVCH, the authors described the clinical findings as follows: "We had two cases of early vitreous cavity haemorrhage (within 4 weeks of surgery), both in non injection group. The haemorrhage was dense and fundus obscuring, but resolved spontaneously during follow up. Both of them have been undergone vitrectomy for vitreous haemorrhage without TRD, with no air, SF6 or silicone as a tamponade. We had five cases of late vitreous cavity haemorrhage before writing of paper (occurring after more than 4 weeks), two in non injection group and three in injection group. Only in one participant in injection group, vitreous cavity haemorrhage was dense and fundus obscuring. In other participants, it presented as recurrent bouts of non fundus obscuring vitreous cavity haemorrhage". Trial registration number: not reported Date study conducted: January 2008 to January 2009 Funding: not reported Conflict of interest: reported that there were none
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were randomly assigned to injection of bevacizumab (injection group) or not (control group), within each subgroup
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding of participants and personnel (performance bias) All outcomes	High risk	Study participants were not masked to which group they had been randomised to
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	All surgeons were masked regarding treatment group, but it was unclear if the outcome assessors were masked
Incomplete outcome data (attrition bias) All outcomes	Low risk	Participants who failed to complete the study follow‐up are clearly accounted for in the results
Selective reporting (reporting bias)	Low risk	All outcomes were reported