Intravitreal Injection of Bevacizumab before Vitrectomy for Proliferative Diabetic Retinopathy

Abstract

To evaluate the use of preoperative intravitreal bevacizumab (IVB) injection in patients undergoing pars plana vitrectomy for complications of proliferative diabetic retinopathy (PDR). In this prospective surgeon-masked randomized clinical trial, 40 eyes of 40 diabetic patients who were candidates for vitrectomy were randomly assigned to receive 2.5 mg IVB 3-5 days before operation (injected group) or no injection before operation (noninjected group). A preoperative complexity score (CS) was recorded. Best-corrected visual acuity, number of endodiathermy applications, backflush needle applications, duration of surgery, and postoperative vitreous hemorrhage were recorded. Twenty-two patients with a CS of 6+/-0.95 in the injected group and 18 patients with a CS of 5.7+/-1.1 in the noninjected group (p=0.3) were studied. Postoperative visual acuities were significantly better than preoperative visual acuities. Preoperative and 3-month postoperative visual acuities were the same for both groups; however, in the last follow-up examinations (mean 7+/- 3.6 months) the injected group had better visual acuities than the noninjected group (1.1+/-0.4 and 1.4+/-0.3 logMAR, respectively, p=0.006). Mean surgical time was 62+/-57.3 minutes in the injected group vs 95.5+/-36 minutes in the noninjected group (p=0.03): endodiathermy applications 6.0+/-4.3 vs 11.0+/-5.8 (p=0.004), backflush cannula applications 11.0+/-7.2 vs 18.1+/-7.8 (p=0.004). In non-silicone-filled eyes, no patient in the injected group developed significant postoperative vitreous hemorrhage obscuring the fundus details, while 7 eyes of noninjected eyes had this complication (p=0.01). IVB injection before vitrectomy for PDR facilitates the surgery, and may decrease the rate of postoperative vitreous hemorrhage and improve the visual acuity results of the operation.