Bevacizumab before Diabetic Vitrectomy: A Clinical Trial Assessing 3 Dosing Amounts

Abstract

Purpose: To evaluate the optimal dosing of preoperative intravitreal bevacizumab (IVB) in patients undergoing pars plana vitrectomy (PPV) for manifestations of proliferative diabetic retinopathy (PDR).

Design: Randomized clinical trial.

Participants: Two hundred six patients with severe manifestations of PDR underwent PPV at a single university-based hospital.

Methods: Patients were randomized into 1 of 3 treatment groups: group A received 0.625 mg IVB (0.025 ml) 1 to 10 days before PPV, group B received 1.25 mg IVB (0.05 ml) 1 to 10 days before PPV, and group C received 2.5 mg IVB (0.1 ml) 1 to 10 days before PPV.

Main outcome measures: The primary outcome was best-corrected visual acuity (BCVA) at 6 months. Secondary outcome measures were rates of perioperative tractional retinal detachment (TRD) development, intraoperative and postoperative complications, and incidence of unplanned PPV at 6 months.

Results: One hundred sixty-seven patients underwent PPV and completed 6 months of follow-up. There were no significant differences between treatment groups regarding baseline characteristics, final BCVA, intraoperative complications, postoperative complications, or unplanned PPV rates. There were no patients in group A (0.0%), 3 patients in group B (7.0%), and 5 patients in group C (8.5%) who demonstrated perioperative TRD after IVB administration, but before PPV (P = 0.0283). This difference was significant between groups A and B (P = 0.0494) and between groups A and C (P = 0.0080).

Conclusions: This randomized clinical trial demonstrated that patients receiving the 0.625-mg dose of IVB before PPV for the treatment of PDR-related manifestations showed similar visual acuity, but a lower incidence of perioperative TRD development compared with patients receiving the 1.25-mg and 2.5-mg doses. Clinicians should consider adopting the lowest effective dose, 0.625 mg, into clinical practice. The current study is limited by the lack of a control group receiving no IVB before PPV.