Use of routine antibiotic sensitivity testing for the management of corneal ulcers
V. O. Kowal, S. B. Levey, P. R. Laibson, C. J. Rapuano and E. J. Cohen
Cornea Service, Wills Eye Hospital, Philadelphia, Pa, USA.
OBJECTIVE: To prospectively evaluate the clinical importance of antibiotic
sensitivities for the management of corneal ulcers. METHODS: Thirty-two
consecutive patients referred to the Cornea Service at Wills Eye Hospital,
Philadelphia, Pa. between October 1, 1993, and May 31, 1994, with a
culture-positive corneal ulcer were studied prospectively. Broad-spectrum
empirical antibiotic therapy with intensive topical fortified antibiotics
was initiated after smear and culture results were obtained. The therapy
was modified based on clinical appearance, stain results, or organism
identification. Clinicians were masked to the sensitivity results. RESULTS:
Fifteen patients healed after receiving the initial empirical antibiotic
therapy (group 1). The antibiotic regimens of 6 patients were modified
after the stain and/or culture results were available, although the
clinical appearance suggested continued improvement while taking the
initial regimen (group 2). Eleven patients had ulcers that either failed to
improve or worsened after receiving the initial empirical therapy (group
3). Seven of these patients ultimately improved with a change in therapy;
treatment failed in 4 patients. Nine patients (5 for whom antibiotic
therapy succeeded and 4 for whom it failed) should have been adequately
treated by the initial antibiotic therapy, according to sensitivity
results. In the remaining 2 patients, in vitro sensitivity testing did not
include the antibiotics used for the initial treatment. In all cases, the
organisms were sensitive to the empirically altered regimen of antibiotics.
CONCLUSIONS: These preliminary results suggest that routine antibiotic
susceptibility tests do not provide clinically useful information for the
management of corneal ulcers. The identification of the organisms based on
the results of smears and cultures was sufficient for the selection and
modification of topical antibiotic therapy.
