Reply to comment on: Effect of topical povidone–iodine 10% plus levofloxacin 0.5% one hour before cataract surgery in eliminating perioperative conjunctival flora: randomized clinical trial

Abstract

We thank Kanclrez et al. for their thoughtful comments on our recently published article.1 Previous studies showed that the povidone-iodine (PVI) application could not render sterile conjunctiva in all cases.2 Indeed, the application of 5% PVI on the conjunctiva may need 15 minutes to offer its maximum effect, which is much longer than the time lapsed in a typical theater.3 Our findings further prove that the double application of PVI on the conjunctiva in a real operating theater enhances the possibility of conjunctival sterilization. The reason that we took T3 before routine preparation and drape was to minimize any risks imposed on the patients by intervening after the final drape. Although our method does not exactly match a real scenario, in our opinion, the results could still be applied to similar clinical settings. The routine conjunctival disinfection in our setting comprised periorbital disinfection with 10% PVI and 1 mL flush of 5% PVI, which remained for at least 3 minutes before washing out with a balanced salt solution. We admit the flaw in the method that has been chosen for applying levofloxacin, and we acknowledged this limitation in the Discussion section of the original article.2 However, it should be noted that some other studies have proved the efficacy of preoperative levofloxacin.4 And, the effectiveness of intracameral antibiotics does not free us from maximum preoperative disinfection, and each of them has a distinct role. Regarding the method of anesthesia, all the patients were collected from an educational hospital, in which many patients are routinely treated with light general anesthesia and laryngeal mask insertion. The reason behind this is that many of them are uncooperative for resident-performed surgery. Although many patients are also treated with topical anesthesia at the same center, we preferred to include only one type of anesthesia for more compatibility. Their ocular or systemic characteristics, however, should not differ from those operated on with topical anesthesia, and hence, any resultant bias is unlikely. Finally, we are aware that the current standard preoperative disinfection is quite effective for most cases; however, without a doubt, the ocular surface of some cases may not render sterile by about 3 minutes of the application of PVI. Thus, we suggested that it might be helpful to use adjuvant preoperative PVI drops for the patients at a greater risk of conjunctival bacterial contamination (such as those with a lid or ocular surface disorder), cases who could not effectively handle a subclinical infection (for example, systemic immunosuppression), or monocular patients, in whom the endophthalmitis could be catastrophic. Nonetheless, the value of additional PVI drops for each of the mentioned scenarios needs verification by appropriate studies.