October 18, 1995
Media Contact: Marc Kusintz
Phone: (410) 955-8665
Johns Hopkins researchers have shown that a new antibiotic eyedrop treatment for a potentially blinding eye infection called bacterial ulcerative keratitis is easier to use and just as good as the standard therapy, which uses a mixture of two other antibiotics. Patients also suffer less discomfort from the new treatment than from the standard therapy.
"This study, which is the first to compare the two treatments, should change the guidelines for treating bacterial keratitis," says Terrence P. O'Brien, M.D., assistant professor of ophthalmology and director of ocular infectious diseases at the Hopkins Wilmer Eye Institute. O'Brien is the principal investigator and lead author of the paper, published in the October issue of Archives of Ophthalmology.
The study also found that the single antibiotic drug ofloxacin causes less irritation and burning in the eye than the standard treatment, according to O'Brien, who led the 28-center study group called the Bacterial Keratitis Study (BacKerS). Ofloxacin, is already used for conjunctivitis, an infection of the lining of the eye.
The current standard treatment for bacterial keratitis is a 'fortified' (concentrated) mix of two antibiotics, tobramycin and cefazolin, prepared one-at-a-time by pharmacists. The heavy concentration is needed to penetrate into the cornea and achieve high drug levels there.
But the mixtures can be too strong, too weak, or even be accidentally contaminated by germs, according to O'Brien.
However, the ofloxacin solution is prepackaged in the correct concentration, making it easier to use and less likely to be contaminated.
"Some doctors were already using the new treatment because they thought it was superior to the fortified antibiotic mixture," O'Brien says. "But we needed proof before we could recommend changing the standard of practice for the initial treatment of this potentially severe eye disease."
The national research team studied 140 patients who had ulcerative keratitis, treating 73 patients with ofloxacin and 67 with the fortified antibiotic mixture. Neither the physicians nor the patients knew which treatment was being used. After four weeks of treatment, the corneas of almost 90 percent of the ofloxacin group and 86 percent of the fortified antibiotics group had healed.
The other Hopkins authors of the paper are Maureen Maguire, Ph.D., Nancy Fink, John Gottsch, M.D., and Walter Stark, M.D.
The study was supported by the Allergan Corporation, a manufacturer of ofloxacin.