Dual application versus single application of povidone-iodine in reducing surgical site contamination during strabismus surgery

Purpose To investigate the contamination rates in patients undergoing strabismus surgery who received a single versus a dual application of povidone-iodine. Methods Patients undergoing strabismus surgery were divided into two groups of approximately equal size. Prior to surgery, the surgical sites for both groups were prepared by applying 4 drops of povidone-iodine 5% directly into the conjunctival fornices, after which the eyelashes were cleaned with cotton tips soaked with povidone-iodine 5%. Sterile gauze pads soaked with povidone-iodine 5% were used to clean the periocular skin. After lid speculum placement, the patients in the dual application group received an additional 2 drops of povidone-iodine in the conjunctival fornices. Intraoperatively, the conjunctiva, sclera, needles/sutures, and lid speculum were cultured. Gram stain and cultures were obtained and quantified. Contamination was defined as any bacterial growth on blood agar plates at 2 days. Results A total of 104 patients (aged 7 months to 79 years) were included. The single application group had a 25% contamination rate of surgical site and sutures; the dual application group, a 10% contamination rate. This difference was statistically significant ( P = 0.03). The rate of eyelid speculum contamination was unaffected by additional applications (12.5% contamination rate in both groups [ P = 0.5]). The additional application of povidone-iodine affected the contamination rate of the conjunctival incision site the most, with a decrease from 20.5% to 5% ( P = 0.02). Conclusions In our study cohort a second application of povidone-iodine significantly decreased the rate of contamination of the surgical site and sutures. It did not affect contamination of the lid speculum.