Additional preop antiseptic drops may reduce postop endophthalmitis

Eur J Ophthalmol. 2011;doi:10.5301/ejo.5000093.

Additional povidone iodine 10% drops before cataract surgery significantly reduced postoperative conjunctival bacterial contamination, a study found.

"The patient's own conjunctiva, eyelid and nose are considered to be the main sources of bacteria causing infection," the study authors said. "It has been shown that a certain number of inoculated bacteria is necessary to overcoming host defense mechanisms for the development of fulminant postoperative endophthalmitis. Therefore, preoperative reduction of the conjunctival bacterial load may be beneficial in the prevention of infection."

The prospective, randomized study included 263 eyes of 242 patients who underwent cataract surgery.

All eyes underwent routine periorbital disinfection with povidone iodine 10% and conjunctival irrigation with 10 mL of povidone iodine 1%. A study group of 132 eyes received three drops of povidone iodine 10% in the conjunctival sac; a control group of 131 eyes received no additional drops.

Investigators took culture samples before the application of povidone iodine, after conjunctival irrigation, before cataract surgery and at the conclusion of surgery.

Study results showed that patients in the study group had significantly fewer positive cultures than controls (P = .03) at the conclusion of surgery; contamination was 16% in the control group and 4% in the study group.

After the application of povidone iodine, the positive culture rate was 12% in the study group and 28% in the control group (P = .01).

"Further studies could be considered to quantify the effects of 10% [povidone iodine] drops on the conjunctival bacterial flora relative to the risk of postoperative endophthalmitis," the authors said.