Abstract
Purpose: :
To evaluate the toxicity of varying doses of infliximab when injected intravitreally in rabbits. Infliximab, a US Food and Drug Administration–approved antiinflammatory drug for rheumatoid arthritis and Crohn’s disease, has been described as an alternative or adjunct drug for chronic recurrent uveitis, especially Behcet’s disease, and diabetic retinopathy.
Methods: :
Twenty New Zealand albino rabbits were divided into five groups (n=4). The anesthetized animals were treated in accordance with the ARVO guidelines on the care and use of animals in research. The rabbits were injected intravitreally with 125 µg, 250 µg, 500 µg, 1.25 mg or 2.5 mg of infliximab in 0.1 ml in one eye and 0.1 ml saline solution in the contralateral eye. All animals were examined using indirect ophthalmoscopy and slit–lamp biomicroscopy before intravitreal injection and on days 1, 7 and 14 postinjection. Electroretinography (ERG) was performed before any treatment and on day 14 before the animals were euthanized. Histological preparations of the enucleated eyes were examined for retinal toxicity.
Results: :
Histological and ERG examinations of eyes given up to1.25 mg of infliximab demonstrated no retinal toxicity. One of 4 eyes in the 2.5–mg group had histological toxicity and some significant decrease in ERG.
Conclusions: :
Intravitreal infliximab at doses up to 1.25 mg is nontoxic to the retina. Intravitreal injected infliximab should be evaluated for efficacy in the treatment of various intraocular inflammatory diseases.
Keywords: drug toxicity/drug effects • inflammation • uveitis-clinical/animal model