Randomized Controlled Trial of Efficacy of Povidone-Iodine in Reducing Bacterial Load Prior to Surgery After Premedication With Gel Versus Drops

Teichman, Joshua

Randomized Controlled Trial of Efficacy of Povidone-Iodine in Reducing Bacterial Load Prior to Surgery After Premedication With Gel Versus Drops

Sunday, April 27, 2014: 3:58 PM

Room 152 (Boston Convention and Exhibition Center)

Joshua C. Teichman, MD, MPH, University of Ottawa Eye Institute, Oakville, ON, Canada

Michael Ying Kit Mak, BHSc, University of Toronto, North York, ON, Canada

Nina Ahuja, MD, FRCSC Hamilton, ON, Canada

Dalia M. Eino, MD, McMaster University, Hamilton, ON, Canada

Varun Chaudhary, MD, FRCSC, McMaster University, Hamilton, ON, Canada

Narrative Responses:

Purpose
Recent laboratory studies suggest that the antiseptic effect of povidone-iodine may be inhibited by application of gels to the eye, including lidocaine, as may commonly be used prior to cataract surgery. No clinical studies have been performed. The purpose of this study is to elucidate if this is seen clinically.

Methods
Prospective, masked, randomized controlled trial of 104 patients. Sample size calculation was performed. Patients presenting for uncomplicated cataract surgery were included if they were able to give informed consent. Exclusion criteria included hypersensitivity to study medications. One hour prior to surgery, patients were randomized to gel composed of lidocaine, cyclopentolate, phenylephrine, diclofenac, and moxifloxacin, or to the above medications in liquid form. In the operating room, the periocular skin was cleansed with 10% povidone-iodine, and the eye with 5% povidone-iodine. The conjunctiva was swabbed and plated. Colony forming units were read by masked microbiology readers. Regression analysis was performed.

Results
One hundred four eyes of 101 patients were included. Fifty two eyes were randomized to gel and 52 to liquid drops. Prior to randomization, there were no significant differences in mean colony forming units (CFU) on blood or chocolate agar between the groups (p = 0.3197 for both). Post-povidone-iodine, mean CFUs was 1.92 in both groups on both blood and chocolate agar. Multiple linear regression analysis to compare between the groups with post-povidone-iodine CFUs as the outcome variable and controlling for pre-randomization CFUs revealed no significant difference between the groups on blood or chocolate agar (p = 0.989 for both).

Conclusion
This prospective, masked, randomized controlled trial evidences that there is no statistically significant difference in colony forming units after povidone-iodine antisepsis in patients treated with topical gel or liquid medication prior to cataract surgery.