Intravitreal injection of bevacizumab before vitrectomy for proliferative diabetic retinopathy

Abstract

Purpose: To evaluate the use of preoperative intravitreal bevacizumab (IVB) injection in patients undergoing pars plana vitrectomy for complications of proliferative diabetic retinopathy (PDR).

Methods: 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.

Results: 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).

Conclusions: 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.