Objective: To investigate antimicrobial effectiveness of povidone-iodine (Betadine) in reducing bacterial load of corneal ulcers before patients were given antibiotics.
Methods: Patients with corneal ulcers were randomized to Betadine or placebo group. Ulcers were cultured before and after a 10-minute application of 5% Betadine or preservative-free artificial tears. All patients were then treated with standard antibiotic medications. The number of colony-forming units before and after Betadine or placebo was compared.
Results: Eighteen patients were randomized to Betadine and 17 to placebo group. In the Betadine group, 8 (44%) of 18 ulcers were culture-positive, either before and/or after pretreatment, and in the control group, 9 (53%) of 17 were culture positive. There was No statistical difference in colony-forming units change after Betadine versus artificial tears application was detected (P-value = 0.16, t-test). In Betadine group, 3 (17%) of 18 of patients showed improvement, ie, had fewer colonies after drop application; and in the placebo group, 7 (41%) of 17 showed improvement, (P = 0.15, Fisher exact t test.)
Conclusions: A single application of 5% Betadine did not reduce the bacterial load of corneal ulcers more than just scraping/rinsing alone. This is likely the result of the lack of penetration deep into the corneal stroma and number of organisms present. Other factors may be involved.