Evaluation of glutaraldehyde and povidone iodine for sterilization of wide-field contact vitrectomy lenses

Background and objective: Wide-field vitrectomy contact lenses are currentl y sterilized with ethylene oxide gas, and other lenses with autoclaving. To maintain a large inventory or possibly run the risk of loss of lens qualit y with repeated autoclaving, glutaraldehyde 2% and povidone iodine 5% solut ion were evaluated as possible sterilizing agents. Materials and methods: Ethylene oxide presterilized lenses were contaminate d with known concentrations (10(5) organisms/mL) of bacteria (S epidemidis, P aeruginosa, B subtilis), and fungi (A flavus, C albicans) for 5 minutes. The test lenses were treated with glutaraldehyde or povidone iodine for 5, 10, 30, 60, and 120 minutes, and controls with sterilized water for a simi lar duration. Following treatment, both test and control lenses were sample d with sterile cotton swabs. The swabs were cultured for bacteria (tryptone soya broth 48 hours), and fungi (Saubourd's dextrose broth 5 days). Results: The culture was negative for both glutaraldehyde- and povidone iod ine-treated lenses against all organisms at all time points except B subtil is, which needed 120 minutes treatment. Conclusion: Two hours contact time with glutaraldehyde 2% or providone iodi ne 5% can sterilize vitrectomy contact lenses against common bacteria and f ungi without affecting lens quality.