Ototoxic Effect of Iodine Disinfectants

Abstract

Disinfectants which could trickle into the middle ear through a perforated drum during the skin sterilization preceding otosurgery might cause inner ear damage resulting in deafness. Chlorhexidine, benzethonium- and benzalkonium chloride, when introduced into the tympanic cavity of guinea pigs, will cause extensive damage to the neuroepithelial receptors of the inner ear. Iodine, frequently used for skin disinfection, was investigated for ototoxicity by locally exposing the middle ear in guinea pigs. The duration of exposure was 10, 30 or 60 min. The animals were sacrificed 2 wk later, and the organs of Corti and neuroepithelial receptors of the vestibular part of the inner ear were studied as surface preparations in phase-contrast microscopy. Slight damage occurred in the basal parts of the organ of Corti of those ears exposed to iodine or iodophor in 70% alcohol for 60 or 30 min and damage to the vestibular receptors was observed in ears exposed to iodophore in 70% alcohol for 60 min. In ears exposed to iodine or iodophore in distilled H2O, no damage to the inner ear sensory epithelia was revealed.