Evaluation of delaying effects of different short‐term dosage regimens of topical ciprofloxacin on corneal ulcer healing in an avian model

BACKGROUND: Knowledge on possible delaying effects of topical ciprofloxacin on corneal ulcer healing is scarce in avian patients. OBJECTIVES: The study evaluates effects of different dosage regimens of topical ciprofloxacin on healing of corneal ulcer in an avian model. METHODS: One hundred and fifty adult layers were randomly allocated into two equal categories each consisted of 5 groups (n = 15): 1, negative control (NC, normal cornea); 2, positive control (PC) (birds with experimental corneal ulcer); and 3, 4 and 5, birds with corneal injury that received ciprofloxacin 0.3% topically q6h, q8h and q12h, respectively for 3 (category 1) or 5 days (category 2). Corneas were excised for histopathological evaluation and determination of MMP‐9 expression. RESULTS: While no significant difference was observed in daily‐measured fluorescein‐stained ulcer size among ciprofloxacin‐treated birds and PC group in category 1, birds in PC group of category 2 had significantly smaller ulcers as compared to antibiotic‐treated birds at the end of experiment (p < 0.01 for all cases). Histopathological evaluations at the end of the experiment showed no significant difference among PC and ciprofloxacin‐treated birds of both categories for almost all of the assayed parameters. Over expression of MMP‐9 mRNA was observed in PC group after 3 and 5 days of ulcer induction compared to NC groups. Its expression in ciprofloxacin‐treated birds of both categories remained close to PC groups. CONCLUSIONS: While ciprofloxacin administration for 3 days does not affect ulcer healing, it delays healing process at the end of 5 days of treatments in an avian model of corneal ulcer injury. This delaying effect is not associated with a drastic change in MMP‐9 expression.