title: The effect of adjunctive intravitreal bevacizumab for preventing postvitrectomy hemorrhage in proliferative diabetic retinopathy.
abstract: OBJECTIVE
  To assess the effects of preoperative and intraoperative intravitreal bevacizumab (IVB) injection on the incidence of postoperative vitreous hemorrhage (VH) after vitrectomy for proliferative diabetic retinopathy (PDR).
  
  
  METHODS
  Prospective, randomized, clinical trial.
  
  
  METHODS
  One hundred seven eyes of 91 patients undergoing pars plana vitrectomy (PPV) for the management of PDR-related complications were enrolled.
  
  
  METHODS
  One hundred seven cases were assigned randomly to either group 1 (intravitreal 1.25 mg/0.05 ml bevacizumab injection 1 to 14 days before PPV), group 2 (intravitreal 1.25 mg/0.05 ml bevacizumab injection at the end of PPV), or group 3 (no IVB injection).
  
  
  METHODS
  The primary outcome was the incidence of early (≤ 4 weeks) and late (> 4 weeks) recurrent VH. Secondary outcome measures were the initial time of vitreous clearing (ITVC) and best-corrected visual acuity (BCVA) at 6 months after surgery.
  
  
  RESULTS
  The incidences of early recurrent VH were 22.2%, 10.8%, and 32.4% in groups 1, 2, and 3, respectively (P = 0.087). A subgroup pairwise analysis showed significantly decreased early VH incidence in group 2 compared with that of group 3 (P = 0.026). The incidences of late recurrent VH were 11.1%, 16.2%, and 14.7% in groups 1, 2, and 3, respectively (P = 0.813). The ITVC in groups 1, 2, and 3 were 26.4 ± 42.5 days, 10.3 ± 8.2 days, and 25.2 ± 26.1 days, respectively. The ITVC was significantly shorter in group 2 compared with that in groups 1 and 3 (P = 0.045 and P = 0.015, respectively). The BCVA at 6 months after surgery did not differ significantly among the 3 groups (P = 0.418).
  
  
  CONCLUSIONS
  This study found no substantial evidence to support the adjunctive use of preoperative IVB to reduce postoperative recurrence of VH in vitrectomy for PDR. For select cases in which adjunctive IVB use is considered, intraoperative administration seems to be the better option for reducing postoperative VH.
  
  
  BACKGROUND
  The author(s) have no proprietary or commercial interest in any materials discussed in this article.
authors: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
authors: Jeeyun
authors: J
authors: Ahn
authors: Se Joon
authors: SJ
authors: Woo
authors: Hum
authors: H
authors: Chung
authors: Kyu Hyung
authors: KH
authors: Park
mesh_terms: D020533:Angiogenesis Inhibitors / Q000008:administration & dosage*; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage*; D000068258:Bevacizumab; D017024:Chemotherapy, Adjuvant; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D015994:Incidence; D058449:Intravitreal Injections; D008297:Male; D008875:Middle Aged; D019106:Postoperative Hemorrhage / Q000517:prevention & control*; D011446:Prospective Studies; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014792:Visual Acuity / Q000502:physiology; D014821:Vitrectomy; D014823:Vitreous Hemorrhage / Q000517:prevention & control*
chemical_list: D020533:Angiogenesis Inhibitors; D061067:Antibodies, Monoclonal, Humanized; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab