The intravitreal penetration of orally administered ciprofloxacin in humans.

To evaluate the penetration of ciprofloxacin, a new wide-spectrum oral antibiotic, into the vitreous, ciprofloxacin was administered orally to 21 patients who were scheduled to undergo vitreal surgery. Seven patients received 750 mg ciprofloxacin 4 hr before surgery (group I), seven patients received this dose 8 hr before surgery (group II), and seven patients received two 750-mg doses of oral ciprofloxacin every 12 hr. The last dose was administered 12 hr before surgery (group III). Vitreous and blood samples were collected simultaneously and assayed for ciprofloxacin concentrations by bioassay and high-performance liquid chromatography.