Comparison of the effects of povidone-iodine 5%, polyhexamethylene biguanide, and chlorhexidine as a preoperative antiseptic in endophthalmitis prophylaxis in patients undergoing phacoemulsification cataract surgery

This study aims to compare the efficacy and toxicity of povidone-iodine (PI) 5%, polyhexamethylene biguanide (PHMB) 0.02%, and chlorhexidine 0.02% in patients undergoing phacoemulsification cataract surgery.

This single-center, randomized study was done on 330 patients who referred to Feiz hospital in Isfahan and scheduled for cataract surgery. They were assigned randomly to 1 of 3 groups of 110 eyes who received 1 drop of PI 5% in group 1, 1 drop of PHMB 0.02% in group 2 and 1 drop of chlorhexidine 0.02% in group 3. Pre-operative Cultures samples were obtained without any topical application and it was repeated 5 min after use of antiseptic solutions. Cultures were obtained from the inferior conjunctival fornix, using sterile culture swabs while avoiding contact to the eyelids and lashes.

The numbers of colony-forming units (CFUs) did not differ significantly among the three groups (P = 0.149 and P = 0.260, respectively). After the intervention, CFUs numbers in the three groups were decreased with a significant difference in both blood and chocolate agars (P = 0.304 and P = 0.136, respectively). Of the 317 eyes, 108 (34.1%) showed no bacterial growth in the pre-preparation period, which was similar in the three groups. Staphylococcus epidermidis was the most common isolated bacteria. Conjunctival injection was significantly different among studied groups (P = 0.0001), five patients in iodine group had severe conjunctival injection and no one in the other group. SPE was significantly fewer in chlorhexidine group than PHMB and iodine groups (P = 0.0001).

Pretreatment with 5% Povidone-Iodine (PVI) for at least 15 min or repeated applications over 10 min is effective in the reduction of conjunctival organisms, and results in less postoperative endophthalmitis.