Bacterial Detection Rate and Surgical Outcome in Povidone-Iodine Irrigation After Nasolacrimal Duct Intubation

PURPOSE: In various ophthalmic surgical procedures, 0.25% povidone-iodine (PI) solution is used to prevent infections. This study examined the bacterial colonisation before and after endoscopic nasolacrimal duct intubation irrigated with PI solution and investigated the relationship between bacterial detection and surgical failure. METHODS: A retrospective study at Saitama Medical University Hospital. We enrolled 113 patients (33 men, 80 women) who underwent lacrimal intubation surgery between April 2016 and December 2018. Preoperatively, the lacrimal pathways were washed with normal saline solution, which was subsequently cultured. The sites of obstruction in the lacrimal pathway were endoscopically determined, perforated, and intubated. The tubes were afterward either irrigated with 0.25% PI or normal saline every 2 weeks. After 8 weeks, a piece of the removed lacrimal tube was cultured. We characterized the pre- and postoperative bacterial cultures. RESULTS: We enrolled 54 and 52 patients in PI and saline groups (mean age: 69.1±9.2 and 73.2±7.2 years), respectively. In the PI group, Staphylococcus epidermidis was less frequently detected postoperatively than preoperatively. S. oralis and Candida parapsilosis were identified more often postoperatively (P=0.02, P=0.01, respectively). The PI group had significantly lower bacterial detection rate than the saline group (P=0.01). However, the surgical failure rates did not differ between groups. In surgical failure patients, the postoperative rate of Pseudomonas aeruginosa was very high (75%). CONCLUSION: PI reduces the bacterial detection rate but does not improve the surgical success rate. P. aeruginosa is associated with an increased risk of surgical failure.