Topically administered norfloxacin compared with topically administered gentamicin for the treatment of external ocular bacterial infections. The Worldwide Norfloxacin Ophthalmic Study Group.

In this double-masked study, we randomly assigned 488 patients with clinical signs of acute bacterial conjunctivitis or blepharitis, or both, to treatment with either norfloxacin ophthalmic solution 0.3% (245) or gentamicin ophthalmic solution 0.3% (243) for one week. Of the patients with positive cultures, 71% (85 of 120) of the norfloxacin-treated patients and 65% (86 of 133) of the gentamicin-treated patients were clinically cured. An additional 25% (30 of 120) of norfloxacin-treated patients and 32% (43 of 133) of gentamicin-treated patients were clinically improved. On the basis of posttreatment cultures, 89% of all cultured bacteria were eradicated (146 of 179 organisms) or suppressed (14 of 179 organisms) after treatment with norfloxacin. The condition of five norfloxacin-treated patients did not clinically improve, compared with the condition of eight gentamicin-treated patients. Both antibiotics had similar efficacy against gram-positive and against gram-negative organisms. One norfloxacin-treated patient and two gentamicin-treated patients withdrew from the study because of local intolerance. Norfloxacin appears to be an effective and relatively safe agent for the treatment of bacterial infections of the eyelids or conjunctiva, or both. In this study, norfloxacin was clinically and microbiologically similar in activity to gentamicin.