title: Bevacizumab treatment reduces retinal neovascularization in a mouse model of retinopathy of prematurity.
abstract: OBJECTIVE
  To evaluate the effect of different bevacizumab concentrations on retinal neovascularization in a retinopathy of prematurity (ROP) mouse model.
  
  
  METHODS
  A total of 60 of C57BL/6 J mice were exposed to 75%±2% oxygen from postnatal d7 to postnatal d12. Fifteen nonexposed mice served as negative controls (group A). On d12, 30 mice (group C) were injected with 2.5 µg intravitreal bevacizumab (IVB), 30 mice (group D) were injected with 1.25 µg IVB in one eye. The contralateral eyes were injected with balanced salt solution (BSS) (control group=group B). The adenosine diphosphatase (ADPase) histochemical technique was used for retinal flat mount to assess the oxygen-induced changes of retinal vessels. Neovascularization was quantified by counting the endothelial cell proliferation on the vitreal side of the inner limiting membrane of the retina. Histological changes were examined by light microscopy. The mRNA levels of vascular endothelial growth factor (VEGF) were quantified by Real-time PCR. Western-blotting analysis was performed to examine the expression of P-VEGFR.
  
  
  RESULTS
  Comparing with the control group B, regular distributions and reduced tortuosity of vessels were observed in our retinal flat mounts in groups C and D. The endothelial cell count per histological section was lower in groups C (P<0.0001) and D (P<0.0001) compared with the control group B. Histological evaluation showed no retinal toxicity in any group. In all oxygen treated groups VEGF mRNA expression was significantly increased as compared to age-matched controls. No significant change in VEGF mRNA expression could be achieved in either of the treatments or the oxygen controls. The results of the Western blot were consistent with that of the Real-time PCR analysis.
  
  
  CONCLUSIONS
  An intravitreal injection of Bevacizumab is able to reduce angioproliferative retinopathy in a mouse model for oxygen-induced retinopathy.
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China ; Department of Ophthalmology, Taixing People's Hospital, Taixing 225400, Jiangsu Province, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Feng
authors.affiliation: Department of Ophthalmology, Taixing People's Hospital, Taixing 225400, Jiangsu Province, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China.
authors.forename: Qing-Huai
authors.initials: QH
authors.lastname: Liu
keywords: bevacizumab (Avastin); intravitreal injection; mouse; retinal neovascularization; retinopathy of prematurity