Effectiveness of intraoperative iodine in cataract surgery: cleanliness of the surgical field without preoperative topical antibiotics

Purpose To verify the possibility that preoperative topical antibiotics are not essential as long as iodine disinfection is performed during surgery. Study design Crossover equivalence trial. Patients and methods In 204 eyes of 102 patients who underwent routine bilateral cataract surgery, 1 eye was treated with intraoperative iodine, and the other, with preoperative topical antibiotics. For the intraoperative iodine eyes, 5 mL of 0.25% povidone-iodine was applied at 2 stages: (1) just after the placement of the speculum and (2) before intraocular lens (IOL) insertion. For the contralateral eyes, preoperative topical antibiotics were administered 3 days before surgery without intraoperative iodine. Conjunctival samples for culture were obtained at 3 time points: (a) presurgery, (b) beginning of surgery, and (c) postsurgery. Real-time polymerase chain reaction (PCR) samples were obtained at the beginning of surgery and before IOL insertion. Intracameral moxifloxacin was applied in all the cases. Results The respective positive bacterial culture rates for intraoperative iodine eyes and preoperative topical antibiotics eyes were 95.1% and 98.0% at (a), 7.8% and 5.9% at (b), and 60.8% and 62.7% at (c). A significant difference in the positive bacterial culture rate was not found at any time point. For the intraoperative iodine eyes, the bacterial DNA copy number at (b) was significantly lower than that for the preoperative topical antibiotics eyes. Conclusions The cleanliness of the operative field without using topical antibiotics was revealed to be equivalent to that of the conventional method (using preoperative antibiotics without intraoperative iodine) as long as intraoperative iodine was used.