title: Decreased prothrombin time after intravitreal bevacizumab in the early period in patients with proliferative diabetic retinopathy.
abstract: OBJECTIVE
  To evaluate the effect of intravitreal bevacizumab (Avastin; Genentech, Inc., San Francisco, CA, USA) (IVB) injection on prothrombin time (PT) in patients with proliferative diabetic retinopathy (PDR) and nondiabetic patients.
  
  
  METHODS
  Eighty-nine patients received primary IVB (1.25 mg) in one eye were investigated. The patients were divided into three groups: 34 PDR (diabetic group), 26 nondiabetic (nondiabetic group) patients received IVB and 29 PDR patients without IVB (control group). The levels of PT were detected before and after IVB in study groups and at corresponding time-points in the control group. Paired samples t-test was conducted to compare the statistical differences of PT in each group.
  
  
  RESULTS
  Significant difference (p < 0.001) of the levels of PT before and after IVB was observed in diabetic group in the early period, and the PT changes (11.0 ± 0.56 before and 10.6 ± 0.45 after IVB) were in fact within the normal range. There were no significant differences in other groups and other time-points (all p > 0.05).
  
  
  CONCLUSIONS
  Intravitreal bevacizumab may lead to a decrease in the levels of PT in the early period after IVB in PDR patients, suggesting a temporarily potential effect of IVB on the extrinsic clotting pathway of blood coagulation cascade in diabetic patients.
authors.affiliation: Department of Ophthalmology, People's Hospital, Peking University, Beijing, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Qian
authors.forename: Yan-Rong
authors.initials: YR
authors.lastname: Jiang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020533:Angiogenesis Inhibitors / Q000008:administration & dosage*; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D001777:Blood Coagulation / Q000187:drug effects; D003930:Diabetic Retinopathy / Q000188:drug therapy*; D005260:Female; D005451:Fluorescein Angiography; D006068:Gonioscopy; D006801:Humans; D058449:Intravitreal Injections; D008297:Male; D008875:Middle Aged; D011517:Prothrombin Time; D015861:Retinal Neovascularization / Q000188:drug therapy*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014792:Visual Acuity; D055815:Young Adult
chemical_list: D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab