Efficacy of ofloxacin vs cefazolin and tobramycin in the therapy for bacterial keratitis. Report from the Bacterial Keratitis Study Research Group.

PURPOSE

To compare ofloxacin solution with a combination of fortified antibiotic cefazolin sodium and tobramycin sulfate solutions in the treatment of bacterial keratitis.

METHODS

Patients under care at any one of 28 participating clinical centers who had an eye with suspected bacterial keratitis were randomly allocated in a double-masked manner to treatment with 0.3% ofloxacin solution or a combination of the fortified antibiotics (1.5% tobramycin and 10.0% cefazolin solutions).

MAIN OUTCOME MEASURES

Time to healing defined as complete re-epithelization, accompanied by a nonprogressive stromal infiltrate for two consecutive visits. Secondary outcome measures included patient symptoms and signs of infection and adverse reactions to study medications. Only patients with a positive bacterial corneal culture were included in most analyses.

RESULTS

A positive bacterial corneal culture was obtained in 140 (56%) of the 248 enrolled patients. The time to healing was similar among the 73 patients receiving ofloxacin and the 67 patients receiving fortified antibiotics (P = .70). By 7 days after study entry, the keratitis in 37% of the ofloxacin group and 38% of the fortified antibiotics group had healed. By 28 days, keratitis in 89% of the ofloxacin group and 86% of the fortified antibiotics group had healed. Two patients receiving ofloxacin and one receiving fortified antibiotics discontinued study medication because of lack of efficacy. Patients receiving ofloxacin reported substantially less burning and stinging on instillation than the patients receiving fortified antibiotics (P < .001). Five of six patients among the 140 with positive bacterial cultures who had study medications discontinued because of ocular side effects were in the fortified antibiotics group; an additional three patients, all in the fortified antibiotics group, among the remaining 108 receiving study medications had ocular side effects.

CONCLUSIONS

The efficacy of ofloxacin solution in treating bacterial keratitis is equivalent to that of the fortified cefazolin and tobramycin solutions. The reduced frequency of ocular toxic effects and the relative ease of preparation of ofloxacin are additional considerations.