Pre- and Intra-operative Intravitreal Bevacizumab Injection in Diabetic Vitrectomy

Not Applicable

Completed

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.

Recruitment & Eligibility

Inclusion Criteria

Patients undergoing first vitrectomy for complications of proliferative diabetic retinopathy such as vitreous hemorrhage, tractional fibrovascular membrane proliferation, tractional or combined retinal detachment)

Exclusion Criteria

Follow-up period of less than 6 months
Intraoperative use of long-acting gas or silicone oil
Repeat vitrectomy after first vitrectomy for diseases other than vitreous hemorrhage
Not first vitrectomy
Uncontrolled hypertension
Medical history of abnormal blood coagulation
Time interval between IVB injection and PPV longer than 2 weeks and recent history (within 3 months) of IVB treatment

Arm && Interventions

Group	Intervention	Description
Preop IVB	Bevacizumab	Patients will receive intravitreal injection of 1.25 mg of bevacizumab (0.05 ml) 1 to 14 days before vitrectomy
Intraop IVB	Bevacizumab	Patients will receive intravitreal injection of 1.25 mg of bevacizumab (0.05 ml) at the end of vitrectomy

Primary Outcome Measures

Name	Time	Method
Recurrent VH Incidence (Early and Late)	6 months	Recurrent VH was defined as a new episode of grade 1 or more VH occurring more than 1 week after surgery. "Early recurrent VH" was VH occurring \<= 4 weeks and "late recurrent VH" was VH occurring \>4 weeks after surgery.

Secondary Outcome Measures

Name	Time	Method
Visual Outcome	6 months	Best-corrected visual acuity (BCVA) at postoperative 6 months
Initial Time of Vitreous Clearing (ITVC)	6 months	The interval in number of days for VH of grade 1 or more observed at postoperative day 1 to clear-up completely. VH of grade 1 was defined as mild vitreous hemorrhage with visible fundus details, but difficult to evaluate the retinal nerve fiber layer or small vessels.
Postoperative Resolution of Neovascularization	6 months