Penetration of second-, third-, and fourth-generation topical fluoroquinolone into aqueous and vitreous humour in a rabbit endophthalmitis model

AIMS: This study was designed to investigate the penetration of second-, third- and fourth-generation topical fluoroquinolone into aqueous and vitreous humour in a rabbit endophthalmitis model. METHODS: Thirty New Zealand white rabbits were divided into six groups. Left eye was infected with an intravitreal inoculum of Staphylococcus aureus. Groups 1, 2, 3, 4, and 5 received topical ofloxacin, ciprofloxacin, lomefloxacin, levofloxacin, or moxifloxacin treatment 24 h after the inoculation, respectively. No treatment was given to group 6 as the control group (n=5). Aqueous and vitreous samples were obtained 30 min after the last drop. High-performance liquid chromatography was used to determine the fluoroquinolone concentration. RESULTS: In the normal and inflamed eyes, mean aqueous concentrations of ofloxacin were 1.90 and 2.69 mug/ml, ciprofloxacin were 2.16 and 3.65 mug/ml, lomefloxacin were 3.54 and 1.19 mug/ml, levofloxacin were 2.89 and 9.41 mug/ml, and moxifloxacin were 4.92 and 43.33 mug/ml, respectively. Mean vitreous concentrations of ofloxacin were 0.25 and 0.07 mug/ml, ciprofloxacin were 0.08 and 0.32 mug/ml, lomefloxacin were 0.001 and 0.03 mug/ml, levofloxacin were 0.03 and 0.09 mug/ml, and moxifloxacin were 0.28 and 2.68 mug/ml, in normal and inflamed eyes, respectively. Moxifloxacin achieved a significantly higher concentration in aqueous and vitreous humour of infected eyes compared with ofloxacin (P<0.01), ciprofloxacin (P<0.05), lomefloxacin (P<0.01), and levofloxacin (P<0.05). CONCLUSION: This study demonstrated that fourth-generation fluoroquinolone, moxifloxacin, seems to have better penetration to inflamed ocular tissues in rabbit.