Conditions: Proliferative Diabetic Retinopathy Vitreous Hemorrhage
Keywords: Proliferative diabetic retinopathy vitrectomy bevacizumab vitreous hemorrhage
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 126
Healthy volunteers: no

Brief summary:
The purpose of this study is to determine the effect of pre- and intra-operative bevacizumab injection on postoperative vitreous hemorrhage after diabetic vitrectomy.

Detailed description:
Postoperative vitreous hemorrhage(VH) is a common complication after vitrectomy for proliferative diabetic retinopathy. Persistent or recurrent VH can delay visual rehabilitation and give patients much trouble. There have been efforts to lower the incidence of postoperative VH such as using intraoperative gas tamponade and preoperative bevacizumab injection. Bevacizumab(Avastin) is a potent inhibitor of angiogenesis and has been shown to decrease retinal and iris neovascularization in proliferative diabetic retinopathy. Recently there have been reports showing that preoperative intravitreal bevacizumab (IVB) injection could reduce intraoperative bleeding from abnormal vessels and could make surgery easier and more successful.Our hypothesis is that preoperative bevacizumab injection could reduce postoperative VH by way of decreasing the amount of abnormal vessels and intraoperative injection could also reduce postoperative VH by inhibiting the vessel formation after surgery.

To prove our hypothesis, we started the prospective randomized comparative study to determine the effect of pre- and intra-operative IVB injection on postoperative vitreous hemorrhage after diabetic vitrectomy.

Arms:
arm 1: Patients will receive intravitreal injection of 1.25 mg of bevacizumab (0.05 ml) 1 to 14 days before vitrectomy arm 2: Patients will receive intravitreal injection of 1.25 mg of bevacizumab (0.05 ml) at the end of vitrectomy arm 3: Patients will not receive bevacizumab before nor during vitrectomy

Interventions: intervention 1: Bevacizumab
Intervention descriptions: intervention 1: Patients will receive intravitreal injection of 1.25 mg of bevacizumab (0.05 ml)

Protocol document: