Prophylactic Efficacy of Ophthalmic Quinolones in Experimental Endophthalmitis in Rabbits

Abstract

Immediate postoperative prophylaxis would likely be effective in reducing the risk of enterococcal endophthalmitis by topical gatifloxacin.

Effect of dosing interval on the efficacy of topical ophthalmic gatifloxacin against Enterococcus faecalis in an in vitro pharmacokinetic model simulating the local eye compartment

“…This strain was selected to mimic contamination of the aqueous humour by an organism from normal conjunctival flora during surgery and has been used in an experimental rabbit model of endophthalmitis [1]. The minimum inhibitory concentration (MIC) of gatifloxacin was 0.39 mg/L by the agar dilution method.…”

“…An in vitro PK model was set up to simulate the aqueous humour concentration following topical application of 0.3% gatifloxacin ophthalmic solution to rabbit eyes [1]. The aqueous humour concentration was fitted into a one-compartment first-order model using WinNonlin software 2.1A (Pharsight Corp., Mountain View, CA).…”

“…The syringe pump supplied fresh medium at a flow rate of 3.5 mL/h. The chamber, which was jacketed to maintain its temperature at 37 • C, was inoculated with the E. faecalis A-2-7 bacterial suspension at a final concentration of 3 × 10 4 CFU/mL, which was sufficient to cause intraocular inflammation [1]. The bacteria in the central chamber were trapped by membrane filters (API 502200 and HVLP 04700; Millipore) to prevent dilution of the bacteria [10].…”

“…2. The concentration of gatifloxacin in the central chamber was measured by high-performance liquid chromatography (HPLC) as reported previously [1].…”

“…In a previous study, we demonstrated the prophylactic efficacy of a three-times-daily gatifloxacin ophthalmic solution at intervals of 2 h in an in vivo Enterococcus faecalis endophthalmitis rabbit model [1]. Bacterial endophthalmitis is a serious complication of ocular surgery and can result in vision loss [2,3].…”