Abstract
Purpose :
To determine the safe and efficient concentration of povidone-iodine that can be used to sterilize the globe in cases of endophthalmitis.
Methods :
Full-thickness human retina explants were harvested from freshly enucleated (<24 hours) eyes, and 6-mm patches of the retina were incubated with different concentrations (10% - 0.125%) of povidone-iodine at 37 °C within a humidified incubator for up to 48 hours. Retinal patches kept in CO2-independent medium served as controls. At the end of the incubation period retinal cell viability was determined using an ethidinium/calcein-based assay. Quantitative suspension test method was also employed on a Staphylococcus aureus strain to test the antibacterial effects of the studied povidone-iodine concentrations. Results were used to determine the optimum concentration of the povidone-iodine that can achieve the maximum antibacterial effect without retinal toxicity.
Results :
Concentrations of povidone-iodine below 0.5% did not impair the retinal cell viability for up to 48 hours (97.5% vs 96.5%, p = 0.57). Bactericidal effect was observed with all studied concentrations of povidone-iodine; however, this bactericidal effect was more remarkable at concentrations at or above 0.5%.
Conclusions :
Concentrations of povidone-iodine at or below 0.5% can be used to sterilize the globe without causing any retinal cytotoxicity for up to 48 hours. While 0.5% povidone-iodine can be used for the treatment of endophthalmitis and eliminate the concern of bacterial resistance, lower concentrations can be useful for prophylactic purposes after intraocular surgeries or traumatic globe injuries.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.