Topical Effect of Povidone–iodine Compared With Natamycin in Fungal Keratitis Caused by Fusarium solani in a Rabbit Model. A Pilot Study

Abstract

Purpose: : To evaluate the efficacy of topical administration of 0.5% povidone–iodine on experimental Fusarium solani keratitis in rabbits.

Methods: : Fungal keratitis caused by Fusarium solani was induced in the left eye of 24 New Zealand rabbits. The rabbits were randomly divided into 3 different treatment groups: Gr.I: treated with topical 0.5% povidone–iodine hourly (7am – 11pm) for three days; Gr.II: treated with topical 5% natamycin hourly (7am – 11pm) for three days; and Gr.III: treated with topical salt solution hourly (7am – 11pm) for three days. Rabbits were sacrificed and the corneas were excised, macerated and immersed in 10 ml of BHI. Culture samples were plated daily on Sabouraud’s agar for 7 days. The number of colony–forming units was counted.

Results: : Groups I and II showed a greater efficacy than group III comparing the number of rabbits in which there were no growing colonies. However, considering the number of colony–forming units between the 3 groups, there was no statistical significance difference.

Conclusions: : Using this methodology of counting colony–forming units, topical 0.5% povidone–iodine showed no benefit in the treatment of experimental fungal keratitis caused by Fusarium solani when compared with topical 5% natamycin.

Keywords: fungal disease • keratitis • drug toxicity/drug effects