Subretinal bevacizumab detection after intravitreous injection in rabbits.
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.
Dib
Eduardo
E
Department of Ophthalmology, Vitreoretinal Diseases Sector, Federal University of São Paulo, Brazil. dibedu@gmail.com
Maia
Mauricio
M
Longo-Maugeri
Ieda Maria
IM
Martins
Maria Cristina
MC
Mussalem
Juliana Sekeres
JS
Squaiella
Carla Cristina
CC
Penha
Fernando M
FM
Magalhães
Octaviano
O
Rodrigues
Eduardo B
EB
Farah
Michel Eid
ME
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
D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D042461:Vascular Endothelial Growth Factor A; D000068258:Bevacizumab