title: Subretinal bevacizumab detection after intravitreous injection in rabbits.
abstract: OBJECTIVE
  To evaluate subretinal detection of bevacizumab 2 hours after intravitreous injection of 1.25 mg in rabbit eyes.
  
  
  METHODS
  Anterior chamber paracentesis using a 30-gauge needle was performed in nine female Dutch-belted rabbits by removal of 0.05 mL of aqueous humor. Transscleral retinal detachment was performed with a modified 25-gauge infusion cannula connected to a bottle of physiologic saline solution (PSS). The animals were divided into experimental group 1, with intravitreous injection of 0.05 mL of (1.25 mg) with a 30-gauge needle (n = 6) and the control group 2, with intravitreous injection of 0.05 mL of PSS with a 30-gauge needle (n = 3). Two hours after the intravitreous bevacizumab or PSS injection, subretinal fluid was aspirated and immunoassayed to measure the level of bevacizumab. The rabbits were killed by intravenous pentobarbital injection. The eyes were enucleated and fixed in 10% formaldehyde. The pars plana site at which the transscleral cannula was introduced was analyzed by light microscopy, to exclude iatrogenic retinal tears. Eyes with accidental retinal tears were excluded.
  
  
  RESULTS
  Subretinal bevacizumab molecules were detected in the six eyes that received an intravitreous bevacizumab injection. No subretinal bevacizumab was detected in the control eyes. Light microscopy showed no evidence of retinal tears or holes in any rabbits used for the bevacizumab detection and control group.
  
  
  CONCLUSIONS
  Bevacizumab molecules were detected in the subretinal space after intravitreous injection of 1.25 mg of bevacizumab, possibly as the result of diffusion through the retina in a rabbit model.
authors.affiliation: Department of Ophthalmology, Vitreoretinal Diseases Sector, Federal University of São Paulo, Brazil. dibedu@gmail.com
authors.forename: Eduardo
authors.initials: E
authors.lastname: Dib
authors.forename: Mauricio
authors.initials: M
authors.lastname: Maia
authors.forename: Ieda Maria
authors.initials: IM
authors.lastname: Longo-Maugeri
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Martins
authors.forename: Juliana Sekeres
authors.initials: JS
authors.lastname: Mussalem
authors.forename: Carla Cristina
authors.initials: CC
authors.lastname: Squaiella
authors.forename: Fernando M
authors.initials: FM
authors.lastname: Penha
authors.forename: Octaviano
authors.initials: O
authors.lastname: Magalhães
authors.forename: Eduardo B
authors.initials: EB
authors.lastname: Rodrigues
authors.forename: Michel Eid
authors.initials: ME
authors.lastname: Farah
mesh_terms: D020533:Angiogenesis Inhibitors / Q000493:pharmacokinetics*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000493:pharmacokinetics*; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D001826:Body Fluids / Q000378:metabolism*; D005122:Exudates and Transudates / Q000378:metabolism; D005260:Female; D007267:Injections; D011817:Rabbits; D012160:Retina / Q000378:metabolism*; D014018:Tissue Distribution; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors; D014822:Vitreous Body
chemical_list: D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab