Intravitreal Toxicity of Povidone–Iodine in Rabbit Eyes

Abstract

Abstract: : Purpose: The purpose of this study is to examine the relative toxicity of various doses of povidine–iodine (PVP–I) when injected intravitreally. Methods: Sixteen New Zealand albino rabbits were divided in four groups (n=4 each). The animals were anesthetized and treated in accordance with the ARVO statement on the use of animals in ophthalmic and visual research. The rabbits were intravitreally injected with 0.1 ml of 50 µg, 100 µg, 200 µg, or 400 µg of PVP–I in one eye and with saline solution in the other eye. The animals were examined at days 1, 7, and 14 using indirect ophthalmoscopy and slit–lamp biomicroscopy; electroretinography (ERG) was performed before treatment and before the animals were euthanized and the eyes enucleated. Histological preparations were examined to determine retinal damage. Results: One eye in the 400–µg PVP–I group suffered retinal damage. No other deleterious effects were noted by indirect ophthalmoscopy, slit–lamp biomicroscopy, or ERG in any of the eyes treated with lower concentrations of PVP–I or with saline. Conclusions: These results suggest that 200 µg of PVP–I can be administered safely intravitreally in the rabbit eye with no noticeable damage over a 14–day period. This concentration is greater than that which has been previously reported to be bactericidal to many common ophthalmologic infectious agents.

Keywords: antibiotics/antifungals/antiparasitics • drug toxicity/drug effects • endophthalmitis