Injection of intravitreal bevacizumab (Avastin) as a preoperative adjunct before vitrectomy surgery in the treatment of severe proliferative diabetic retinopathy (PDR)

Abstract

To evaluate the use of preoperative intravitreal bevacizumab (IVB) in patients undergoing pars plana vitrectomy (PPV) for complications of proliferative diabetic retinopathy (PDR). We studied 22 patients with severe PDR. A preoperative complexity score (CS) was recorded. Eleven eyes were treated with IVB, 1.25 mg, 5-7 days before PPV (group 1), and 11 eyes underwent direct PPV (group 2). Surgical time and intra-operative manoeuvres were recorded. Main outcome measure was feasibility of surgery, secondary goal was the visual and anatomic outcome at 6 months. The average CS was 5.5, and was similar in the two groups. Mean surgical time was 57 minutes in group 1 vs 83 minutes in group 2; mean tool exchanges was 27 vs 53, intraoperative bleeding 5 vs 15, endodiathermy 2 vs 9. No complications were recorded after IVB. Mean pre-operative BCVA was 1.87 logMAR in group 1 and logMAR 2.04 in group 2. Mean pre-operative BCVA was 1.87 logMAR in the bevacizumab group and 2.04 logMAR in group 2, not significantly different (p = 0.7). Mean post-operative BCVA at 6 months was 0.88 logMAR in group 1 and logMAR 2.01 in control group 2, significantly different (p = 0.01). Post-operative BVCA improved in bevacizumab group from pre-operative value (p = 0.15), while in control group there was non-significant increase (p = 0.96). Anatomical attachment was achieved in 11 patients in group 1 vs nine patients in group 2. IVB administered prior to vitrectomy was well tolerated and reduced active neovascularization, thus facilitating PPV.