Abstract:

Objective    To evaluate the safety and efficacy of Bevacizumab（Avastin） preoperative use in vitrectomy for severe active proliferative diabetic retinopathy (PDR).  Methods    The design of this study was an interventional consecutive, prospective study. Patients were included if they had: (1) tractional retinal detachment, (2) tractionalrhegmatogenous retinal detachment, or (3) tractional detachment complicated with vitreous haemorrhage. Exclusion criteria included: (1) history of thromboembolic events (e.g. cerebral vascular events), or (2) history of vitrectomy in the study eye. An intravitreal injection of 2.5mg (0.1mL) Bevacizumab(Avastin) was preformed 7 days prior to planned vitrectomy. Main outcome measure was feasibility of surgery; secondary outcome measure  was the visual and anatomic result at 6 months.  Results    34 eyes of 30 patients (31-79 years old) with severe active PDR were enrolled. All cases showed remarkable regression of fibrovascular membrane with visually absent vascular component and minimum bleeding during surgical dissection of fibrovascular membrane. Less use of silicone oil was found. Post-operative best correctedvisual acuity improved from pre-operative value (P＜0.01). Anatomical attachment was achieved in all patients.  Conclusion    Intravitreal Bevacizumab（Avastin） administrated prior to vitrectomy is well tolerated and reduces neovascularization, and thus facilitates pars plana vitrectomy. The appropriate time of vitrectomy after Bevacizumab(Avastin) injection should be further evaluated.

Key words: Bevacizumab (Avastin)； Proliferative diabetic retinopathy；  Neovascularization； Pars plana vitrectomy