Reduced anterior chamber contamination by frequent surface irrigation with diluted iodine solutions during cataract surgery

Abstract

Purpose: To verify that ocular surface irrigation with 0.025% povidone–iodine (PI) or 0.0025% polyvinyl alcohol–iodine (PAI) during cataract surgery minimizes bacterial contamination of the anterior chamber. Methods: The study was a prospective, interventional case series. First, the bactericidal effect of PI or PAI against Staphylococcus aureus was evaluated in vitro. Next, in 400 eyes undergoing cataract surgery, the ocular surface was irrigated every 20 seconds during surgery with balanced salt solution (BSS; 200 eyes) or BSS containing 0.025% PI (100 eyes) or 0.0025% PAI (100 eyes). At the completion of surgery, anterior chamber fluid was cultured bacteriologically. Visual acuity (VA) and corneal endothelial cell density were measured before and 7 days after surgery. Results: A marked bactericidal effect was observed when S. aureus was directly exposed for 15 seconds to 0.01% PI or 0.001% PAI diluted in BSS. When the two solutions were stored at room temperature, bactericidal effect did not attenuate after 60 min. The bacterial detection rate at the completion of surgery was significantly reduced in 0.025% PI (0%, 0/100 eyes) or 0.0025% PAI group (0%, 0/100 eyes) compared to BSS group (5%, 10/200 eyes) (p = 0.0340). No differences in postoperative visual acuity and postoperative corneal endothelial cell density were observed between three groups. Conclusion: In cataract surgery, irrigation every 20 seconds of the operative field with 0.025% PI or 0.0025% PAI, both of which contain 0.0025% available iodine concentration, achieved a very low bacterial contamination rate in the anterior chamber.