The purpose of this is study is to assess the efficacy of pre-operative intravitreal bevacizumab (IVB) (Genentech, South San Francisco CA) in improving visual acuity, reducing operative time, complications, intra-operative and post-operative hemorrhage following small gauge pars plana vitrectomy (PPV) (23-gauge, 25-gauge or 27-gauge ) compared to small gauge PPV (23-gauge, 25-gauge or 27-gauge) alone in eyes with tractional retinal detachment (TRD) secondary to proliferative diabetic retinopathy (PDR). Hypothesis: Preoperative IVB may be beneficial for membrane dissection in diabetic tractional retinal detachment with minimally invasive vitreoretinal surgery (23-gauge transconjunctival sutureless vitrectomy [TSV]). In addition, post-operative rebleeding may be decreased.