Adjunctive Intravitreal Bevacizumab with Vitrectomy for Diabetic Vitreous Hemorrhage

Abstract

Background: Postoperative vitreous hemorrhage (VH) following pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR) is a common event, with a reported incidence of 29% to 75%.This complication delays visual rehabilitation, interferes with fundus examination, and may necessitate additional surgical procedures. Vascular endothelial growth factor (VEGF) is an angiogenic mitogen, and the involvement of VEGF in PDR has been suggested by studies that have demonstrated that VEGF concentrations were markedly elevated in both vitreous and aqueous fluids of patients with active PDR compared with samples from patients without diabetes, with NPDR, or with quiescent PDR. Bevacizumab (Avastin®, Genentech, Inc., South San Francisco, CA) is a full-length recombinant humanized monoclonal antibody that binds to all isoforms of VEGF. Aim of the Work: to evaluate the safety and efficacy of intravitreal bevacizumab (IVB) at the end of vitrectomy operation for prevention of postoperative rebleeding in patients with diabetic vitreous hemorrhage. Patients and Methods: The study included 20 eyes of 20 patients undergoing PPV for severe non-clearing vitreous hemorrhage for more than 1 month. Eligible eyes were randomly assigned to one of two groups: Group A (10 eyes) did not receive any intravitreal injection and Group B (10 eyes) received 1.25 mg IVB injection at the end of surgery. All patients were subjected to complete history taking and full ophthalmic examination including best-corrected visual acuity, anterior segment examination, fundus examination and B-scan ultrasonography was performed. All patients underwent three-port pars plana vitrectomy using 23-gauge instrumentation under local anesthesia. At the end of surgery, fluid-air exchange was performed and the intraocular air is left as tamponade in selected cases. The follow up period occurred over 1 week, 1 month and 3 months. The main outcome measures were occurrence of vitreous hemorrhage and BCVA. Results: At 1 month after surgery, the incidence of early postoperative VH was 30% and 20% in Group A and B, respectively (p = 0.641). Mild vitreous hemorrhage (grade 1) was the major component of early VH at 1 month (20% of 30% and 10% of 20%, in Group A and B, respectively). Analysis of changes in the mean BCVA at 1 month after surgery showed significant improvement from the preoperative BCVA in all study groups, the mean differences between pre-BCVA (Log MAR) and post BCVA (Log MAR) among the studied groups was 0.865 ± 0.351 with statistically significant difference between the two groups (p = 0.000).the mean differences between pre-BCVA (Log MAR) and post BCVA (Log MAR) among the studied groups was 0.865 ± 0.351 with statistically significant difference between the two groups (p = 0.000). At 3 months after surgery, the incidence of late postoperative VH was 20.0% and 0.00% in Group A and B, respectively, with no significant difference between the two groups(P=0. 237). Again, analysis of changes in the mean BCVA at 3 months after surgery showed significant improvement to 1.080 ± 0.2098 and 0.870 ± 0.17767 in Group A and B, respectively, with statistically significant difference between the two groups (p >0.027). Conclusion: The incidence of late postoperative vitreous hemorrhage is lower than that of early postoperative vitreous hemorrhage and is not affected by intraoperative intravitreal bevacizumab injection and Adjunctive use of intravitreal bevacizumab with pars plana vitrectomy for complications of PDR is safe and well-tolerated with no serious ocular or systemic adverse events.