Purpose : To investigate the penetration of cefixime and ciprofloxacin to the rabbit eye on the basis of microbial inhibition of aqueous and vitreous humour after oral administration.

Methods : In this experimental study, 36 rabbits (72 eyes) were randomly divided into two groups; group A consisted of 20 rabbits and group B 16 rabbits. Each group was divided into four equal subgroups. The rabbits in each subgroup of group A received 4, 8, 12, and 20 mg/kg of syrup of cefixime every 12 hr respectively and the rabbits in each subgroup of group B received 20, 40, 60, and 80 mg/kg tablet of ciprofloxacin respectively every 12 hr. Immediately after the first dose of the drugs, the anterior chamber of one eye was irrigated randomly by 30-40 cc of ringer lactate solution alongside with mild traumatization of iris. Then by 4, 8, 12, 24 and 72 hr intervals after the 3rd dose, 0.1 cc of aqueous, 0.2-0.5 cc of vitreous, 3 cc of blood and one standard disk of the used antibiotic was placed on culture media of a known bacteria which was completely sensitive to the respective antibiotic. Forty eight hours later, the microbial inhibition zone of each sample and the standard disk of antibiotic were compared.

Results : No microbial inhibition was seen by sample of aqueous and vitreous, although very large zone of inhibition was seen by blood sample and standard disk of antibiotic.

Conclusion : It seems that oral cefixime and ciprofloxacin do not produce an effective dose for microbial inhibition in rabbit eye .