Preop bevacizumab may not reduce postvitrectomy hemorrhage in PDR

There is no consensus yet on the exact timing of intraoperative intravitreal bevacizumab injection before performing pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR) or whether it's better to inject bevacizumab during or before PPV.

This study was designed to assess and directly compare the effect of preoperative and intraoperative bevacizumab injection on the incidence of postoperative vitreous hemorrhage after PPV for PDR-associated complications.

Investigators randomized 91 patients (107 eyes) undergoing PPV for PDR to one of three groups:  bevacizumab injection within two weeks of surgery, bevacizumab at the end of surgery, or no adjunctive treatment. While there was no difference in the rate of late (>4 weeks postop) recurrent vitreous hemorrhages among the three groups, a subgroup analysis found that eyes treated with intraoperative bevacizumab had decreased rates of recurrent vitreous hemorrhage within four weeks of vitrectomy, and also had faster clearing vitreous hemorrhages.

The authors conclude that this study shows there is no definite evidence to support the adjunctive use of preoperative bevacizumab to reduce postvitrectomy vitreous hemorrhage incidence in proliferative diabetic retinopathy. For select cases in which adjunctive bevacizumab treatment is considered, intraoperative administration may be the better option.