Polyvinylpyrrolidone iodine: corneal toxicology and epithelial healing in a rabbit model

Polyvinylpyrrolidone-iodine (PVP-I) is a biocompatible broad spectrum antimicrobial that is widely used as an ophthalmic pre-operative prepping agent. In order to determine if PVP-I is safe for treating corneal ulcers and conjunctivitis, we evaluated the ocular toxicity of frequent dosing in a rabbit model. We evaluated ocular irritation in 18 rabbits according to the McDonald-Shadduck method. Concentrations of 0.5% PVP-I or less were practically non-irritating when administered six times per day. We evaluated corneal epithelial wound healing in 16 rabbits with standardized abrasions. Concentrations of 0.33% PVP-I showed epithelial healing comparable to gentamicin treated eyes and untreated controls. Concentrations of 0.5% PVP-I delayed epithelial healing by one day. Because of its broad spectrum and apparently low toxicity, PVP-I may be a useful treatment for corneal ulcers, keratitis and conjunctivitis.