Intravitreal Ketorolac: Evaluation of Retinal Toxicity

Abstract

Abstract: : Purpose: To evaluate the ocular toxicity of intravitreally injected ketorolac, a non–steroidal anti–inflammatory drug. Methods: Ketorolac was injected into the midvitreous cavity of 16 eyes of New Zealand white rabbits at concentrations of 10 micrograms (mcg) in 3 eyes, 50 mcg (6 eyes), 100 mcg (6 eyes), 1000 mcg (1 eye). The untreated eye served as a control. The volume injected was 0.1 milliliter. Prior to injection, a baseline examination was performed using indirect ophthalmoscopy and electroretinography (ERG). Following injection, the rabbits were clinically examined daily. ERG was repeated prior to enucleation. The rabbits were sacrificed at either 1 or 3 days postinjection, and the eyes underwent light and electron microscopy examinations. Results:No evidence of retinal toxicity was seen in eyes injected with 10 mcg and 50 mcg of ketorolac. No vitreous reaction was seen at any of the drug concentrations. ERG showed a normal b–wave amplitude in dark and light adaptation. Histopathological sections showed mild disorganization of the retina at 1000 mcg dosage. Conclusions: Intravitreal doses of ketorolac at 10 mcg and 50 mcg are nontoxic to rabbit eyes. Intravitreal dosage of 1000 mcg proved to be toxic to the retina.

Keywords: drug toxicity/drug effects • retina • inflammation