[Aqueous humor penetration of topically applied ofloxacin, ciprofloxacin and tobramycin].

OBJECTIVE

To compare the aqueous humor penetration of topically applied ofloxacin, ciprofloxacin and tobramycin in human eyes.

METHODS

Senile cataract patients (125 eyes in 125 cases) receiving phacoemulsification were randomized into three groups: ofloxacin, 42 eyes; ciprofloxacin, 41 eyes and tobramycin, 41 eyes. Each group was randomized into five sub-groups, with 8 or 9 eyes in each sub-group. Each group received either 0.3% ofloxacin, ciprofloxacin or tobramycin topical drops preoperatively. Eyedrops were instilled one drop every 15 minutes for six times. Aqueous samples were obtained from different sub-groups during surgery, 7.5, 15.0, 30.0, 60.0 and 120.0 min after the last drop, respectively. Concentration of the antimicrobial agents was determined by the HPLC (high pressure liquid chromatography).

RESULTS

Aqueous humor concentration of ofloxacin was significantly higher than that of ciprofloxacin at the same period after the last drop. The bioavailability of ofloxacin was 6 times that of ciprofloxacin. Tobramycin could not be detected by HPLC, so its concentration was lower than the minimum detectable level by HPLC (0.05 micro g/ml).

CONCLUSION

Ofloxacin has the best aqueous penetration in human eyes, as compared with ciprofloxacin and tobramycin, which suggests ofloxacin could be the preferred topical medicine for the prevention and treatment of endophthalmitis.