Purpose: To investigate the usefulness of 0.16 mg/0.05 mL intravitreal bevacizumab (IVB) injection 1 day before vitrectomy for proliferative diabetic retinopathy.
Methods: Sixty-two patients with proliferative diabetic retinopathy (66 eyes) with an indication for primary vitrectomy were randomized to IVB group (34 eyes) or sham control group (32 eyes). Intravitreal bevacizumab group received intravitreal injection of 0.16 mg/0.05 mL bevacizumab, and sham control group received sham injection 1 day before vitrectomy. Vitreous fluid was sampled before vitrectomy was started.
Results: Frequency of reoperation due to recurrent vitreous hemorrhage within 4 weeks after surgery was significantly lower (P = 0.033) in IVB group (3.1%, 1/32) than in sham control group (20.6%, 7/34). The number of intraoperative endodiathermy spots (0.63 ± 1.0 vs. 1.3 ± 1.4, P = 0.025) and frequency of postoperative recurrent vitreous hemorrhage (3.1%, 1/32 vs. 23.5%, 8/34, P = 0.017) were significantly lower in IVB group than in sham control group. Vitreous vascular endothelial growth factor concentrations were 1315.3 ± 1153.4 pg/mL in sham control group and 25.0 ± 13.6 pg/mL in IVB group (P < 0.0001).
Conclusion: Intravitreal injection of 0.16 mg/0.05 mL bevacizumab 1 day before vitrectomy blocked vascular endothelial growth factor production in vitreous and significantly reduced the incidence of reoperation due to early postoperative recurrent vitreous hemorrhage.