Comparison of Vancomycin and Cefazolin Therapeutic Effect with Povidone Iodine on Corneal Ulcer in Rabbits

Corneal ulcer is a common cause of blindness in developing countries, as itleads to corneal perforation and blindness if not properly treated. This study aimed to determine the effects of intraocular 5 % and 10 % topical povidone iodine in the treatment of bacterial corneal ulcer in a rabbit model, comparing the effectiveness of vancomycin and cefazolin eye drops. Total of 40 eyes ofrom 20 wild rabbits were randomly assigned to four equal groups, five in each (n = 5), they included; group 1. 5 % povidone iodine and vancomycin; group 2.5 % povidone iodine and cefazolin; group 3.10 % povidone iodine and vancomycin; group 4.10 % povidone iodine and cefazolin (one drop every two hours for seven days and nights). The animals were first anesthetized with ketamine hydrochloride and xylazine chloride. Then, a 27-gauge needle attached to a 1-ml syringe was tunneled through the clear cornea to approximately midstromal depth, stopping at the edge of the 2-mm optical zone. Finally, 0.02 ml of Staphylococcus contaminated media containing about 100 organisms was injected, forming a central intra-stromal infiltrate. There was no statistically significant difference in the density of infiltration, size of infiltration, hypopyon, or fibrin formation between the four groups. However, epithelial defect, stromal edema, conjunctival injection, and chemosis were significantly higher in the 5 % and 10 % povidone iodine groups when compared to the cefazolin and vancomycin groups. Thinning was more common in the cefazolin group. There was one sealed corneal perforation in the cefazolin group at the beginning, and at day 6, one perforation in the cefazolin group and one perforation in the 10 % povidone iodine group also developed. Cefazolin and vancomycin had a superior clinical effect on the staphylococcal corneal ulcers in this study. 5 % and 10 % povidone iodine was toxic to the corneal epithelium. Thinning and perforation was more common with cefazolin.