Topical antibiotic therapy of Pseudomonas aeruginosa keratitis
A. Kupferman and H. M. Leibowitz
The in vivo antibacterial effectiveness in the rabbit cornea of several
commercially available ophthalmic antibiotic preparations was determined
against a single strain of Pseudomonas aeruginosa isolated from a human
corneal ulcer. Each antibiotic was instilled topically at hourly intervals,
and the number of residual viable organisms in the cornea subsequently was
ascertained. In vivo measurements correlated well with in vitro data and
with generally held clinical impressions. Three antibiotics, gentamicin
sulfate, polymyxin B sulfate, and colistin sulfate, suppressed corneal
growth of P aeruginosa in commercially available concentrations. Gentamicin
was slightly more effective than polymyxin B; both drugs were substantially
more effective than colistin. Formulations of gentamicin and polymyxin B
containing approximately four times the quantity of drug found in
commercial preparations eliminated this P aeruginosa strain from the cornea
much more rapidly than did the commercial preparations.
