Prevention and Treatment of Postoperative Endophthalmitis Using Povidone-Iodine

Postoperative endophthalmitis is typically caused by patient's conjunctival bacterial flora or contaminated solutions and instruments. Visual outcome is often poor in severe cases, and treatment is especially difficult when endophthalmitis is caused by multidrug resistant bacteria. Povidone-iodine is used worldwide due to its wide-spectrum antimicrobial activity, absence of resistant bacteria to povidone-iodine, and low cost. Furthermore, the effective concentration against microorganisms and safe concentration for ocular tissues have been well established. For ocular surface washing, the safe and highly bactericidal concentrations range from 0.050 to 0.500%. Repeated washing of the ocular surface with 0.250% povidone-iodine every 20-30 seconds during ophthalmic surgeries eliminates the conjunctival normal flora, minimizing the passage of bacteria into intraocular compartment, and is thus useful for the prevention of endophthalmitis. The concentration range of 0.013%-0.027% is effective for the treatment of endophthalmitis and nontoxic to intraocular tissues. In a small case series, 4 eyes with endophthalmitis were treated by vitrectomy using 0.025% povidone-iodine in Balanced Salt Solution (BSS) PLUS for vitreous irrigation. In all eyes, endophthalmitis was resolved with no ocular complications and visual acuity was improved. When performing ophthalmic surgeries, washing the ocular surface with saline containing 0.250% povidone-iodine every 20-30 seconds is safe for ocular tissues and effective for the prevention of endophthalmitis. A small case series suggested the effectiveness and safety of using irrigation solution containing 0.025% povidone-iodine in vitrectomy for the treatment of endophthalmitis, but this treatment method remains to be established.