title: Development of an experimental model of proliferative retinopathy by intravitreal injection of VEGF165.
abstract: OBJECTIVE
  To develop an experimental model of proliferative retinopathy by intravitreal injection of vascular endothelial growth factor 165 (VEGF165) in pigmented rabbits.
  
  
  METHODS
  A prospective, controlled, comparative intervention study. Six pigmented rabbits (Chinchilla breed) were subjected to intravitreal injection of VEGF165 in their right eye. The left eye was used as control and received an injection of balanced salt solution. In group 1, 3 rabbits received a 10-μg injection, and in group 2, 3 rabbits received a 20-μg injection. At baseline, all subjects were analyzed by anterior biomicroscopy, retinography, fluorescein angiography, and optical coherence tomography (OCT) fundus images. Biomicroscopy and all ancillary examinations were repeated at weeks 1, 2, and 5. In the fifth week after the injection, the rabbits were euthanized and the eyes were enucleated and subjected to histological evaluation.
  
  
  RESULTS
  Seven days after the intravitreal VEGF165 injection, all rabbits developed intense neovascularization of the retina and anterior segment. Neovascularization of the posterior pole was similar in both groups, and the anterior segment was more florid in group 2. At weeks 1 and 2, neovascularization persisted with a minor decrease in conjunctival hyperemia in both groups. At week 5, there was a partial regression of neovascularization of the posterior pole, which was more prominent in group 1 than group 2, with persistent anterior neovascularization in both groups. OCT showed a statistically significant increase in retinal thickness, hyaloid detachment, and tractional retinal detachment. After the 5-week period, ocular histopathological evaluation showed an increase in retinal thickness, hyaloid detachment, and intense neovascularization in both groups, especially group 2.
  
  
  CONCLUSIONS
  This pilot study of a neovascularization model using intravitreal injection of VEGF165 in pigmented rabbits showed that both doses of 10 and 20 μg were successful and effective in inducing vascular growth in the retina and anterior segment and can therefore be used for evaluating drug efficacy in future studies.
authors.affiliation: Department of Ophthalmology, Vision Institute (IPEPO), Federal University of São Paulo , São Paulo, Brazil .
authors.forename: Emmerson
authors.initials: E
authors.lastname: Badaro
authors.forename: Eduardo Amorim
authors.initials: EA
authors.lastname: Novais
authors.forename: Kalil
authors.initials: K
authors.lastname: Abdala
authors.forename: Mikael
authors.initials: M
authors.lastname: Chun
authors.forename: Muller
authors.initials: M
authors.lastname: Urias
authors.forename: Paulo Augusto
authors.initials: PA
authors.lastname: de Arruda Melo Filho
authors.forename: Michel Eid
authors.initials: ME
authors.lastname: Farah
authors.forename: Eduardo Buchele
authors.initials: EB
authors.lastname: Rodrigues
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005451:Fluorescein Angiography; D058449:Intravitreal Injections; D008297:Male; D010865:Pilot Projects; D011817:Rabbits; D012160:Retina / Q000473:pathology; D012163:Retinal Detachment / Q000473:pathology; D015861:Retinal Neovascularization / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D042461:Vascular Endothelial Growth Factor A / Q000008:administration & dosage*; D018630:Vitreoretinopathy, Proliferative / Q000503:physiopathology*
chemical_list: D042461:Vascular Endothelial Growth Factor A