Philip T H Lam1, Mamie Hui, Alvin L Young, Chiu Yeung Chan, Dennis S C Lam. 1. From the Departments of *Ophthalmology & Visual Sciences and †Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, People's Republic of China.
Abstract
PURPOSE: This study aimed to evaluate the efficacy of povidone-iodine (PI) 5% as the only preoperative antiseptic in cataract surgery. DESIGN: Prospective interventional case series. METHODS: Fifty patients undergoing phacoemulsification under topical anesthesia in an outpatient surgery setting in a teaching hospital participated in the study. The preoperative antiseptic regimen consisted of instillation into the conjunctival sac and periorbital scrub with PI 5%. No topical antibiotic was given. Eyelid margin swabs were obtained for bacteriological culture before and after PI antisepsis and at the conclusion of surgery. The number of bacterial species isolated was compared with the Wilcoxon test. Anterior chamber aspirates were taken immediately before and after surgery to determine the rate of contamination. RESULTS: Bacteria were isolated from the eyelid margins of 48 patients (96%; 95% exact confidence interval, 86.3%-99.5%) before surgery, from the eyelid margins of 28 patients (56%) after antisepsis with PI 5%, and from the eyelid margins of 26 patients (56%; 95% exact confidence interval, 41.3%-70.0%) at the conclusion of surgery. The reduction of positive eyelid margin culture was statistically significant (P < 0.0001). Anterior chamber aspirates were positive in 3 patients. One patient with negative growth from anterior chamber aspirates developed culture-negative postoperative endophthalmitis. CONCLUSIONS: Because 56% of eyelids still have positive culture after PI 5% antisepsis, it might not be relied on as the sole preoperative antiseptic measure. Meticulous surgical technique, together with other modalities of preoperative and intraoperative antisepsis, should be used to prevent postoperative endophthalmitis.
PURPOSE: This study aimed to evaluate the efficacy of povidone-iodine (PI) 5% as the only preoperative antiseptic in cataract surgery. DESIGN: Prospective interventional case series. METHODS: Fifty patients undergoing phacoemulsification under topical anesthesia in an outpatient surgery setting in a teaching hospital participated in the study. The preoperative antiseptic regimen consisted of instillation into the conjunctival sac and periorbital scrub with PI 5%. No topical antibiotic was given. Eyelid margin swabs were obtained for bacteriological culture before and after PI antisepsis and at the conclusion of surgery. The number of bacterial species isolated was compared with the Wilcoxon test. Anterior chamber aspirates were taken immediately before and after surgery to determine the rate of contamination. RESULTS: Bacteria were isolated from the eyelid margins of 48 patients (96%; 95% exact confidence interval, 86.3%-99.5%) before surgery, from the eyelid margins of 28 patients (56%) after antisepsis with PI 5%, and from the eyelid margins of 26 patients (56%; 95% exact confidence interval, 41.3%-70.0%) at the conclusion of surgery. The reduction of positive eyelid margin culture was statistically significant (P < 0.0001). Anterior chamber aspirates were positive in 3 patients. One patient with negative growth from anterior chamber aspirates developed culture-negative postoperative endophthalmitis. CONCLUSIONS: Because 56% of eyelids still have positive culture after PI 5% antisepsis, it might not be relied on as the sole preoperative antiseptic measure. Meticulous surgical technique, together with other modalities of preoperative and intraoperative antisepsis, should be used to prevent postoperative endophthalmitis.