Abstract
Abstract: :
Purpose: To compare the currently available treatments for bacterial keratitis and conjunctivitis based on in vitro susceptibility of isolates from ocular infections. Methods: The E–test (®AB Biodisk) was used to determine the minimal inhibitory concentrations of vancomycin, gentamicin, tobramycin, ceftriaxone, erythromycin, trimethoprim/sulfamethoxazole, trovafloxacin, moxifloxacin, gatifloxacin, levofloxacin, ciprofloxacin, and ofloxacin for ocular isolates of the most common bacterial causes of conjunctivitis and keratitis. Ocular isolates of Staphylococcus aureus (n=10), S. epidermidis (n=11), Streptococcus pneumoniae (n=10), Streptococcus viridans group (n=11), Enterococcus species (n=9), Bacillus species (n=11), Pseudomonas aeruginosa (n=9), Serratia marcescens (n=11), and Haemophilus influenza (n=8) were used for this study. Results:Fourth–generation fluoroquinolones had improved gram–positive coverage (moxifloxacin 89% and gatifloxacin 90%) over previous generations (ofloxacin 58%, ciprofloxacin 65%, and levofloxacin 87%). Only vancomycin (97%) exceeded their gram–positive coverage, and only gentamicin (100%) surpassed their gram–negative coverage (moxifloxacin 86% and gatifloxacin 89%). A combination of vancomycin and gentamycin would have covered 100% of tested isolates, and a combination of gentamycin and ceftriaxone would have covered all gram–negative isolates (94% over all), whereas gatifloxacin covered 91% and moxifloxacin 90% over all. Conclusions: Gatifloxacin and moxifloxacin are the most effective monotherapy for ocular infections. While the spectrum of action of the 4th–generation fluoroquinolones is somewhat less than combinations of fortified or commercially available topical antibiotics, their superior side–effect profile and ease of use are clear advantages over combinations.
Keywords: keratitis • conjunctivitis • antibiotics/antifungals/antiparasitics