Abstract
Purpose: :
To analyze the therapeutic effectiveness of early treatment with vancomycin, gatifloxacin, or these antibiotics combined with each other or with prednisolone for the treatment of experimental B. cereus endophthalmitis.
Methods: :
Rabbit eyes were intravitreally injected with approximately 100 cfu of B. cereus. Eyes were then intravitreally injected at 2, 4, or 6 h postinfection with gatifloxacin alone (0.3%), vancomycin alone (1.0%), vancomycin and gatifloxacin, vancomycin and prednisolone (1.0%), gatifloxacin and prednisolone, or prednisolone alone. Eyes were analyzed by electroretinography, bacterial quantitation, biomicroscopy, histology, myeloperoxidase activity and antibiotic penetration analysis.
Results: :
Eyes treated at 2 h postinfection with either antibiotic maintained significantly higher ERG amplitudes compared to eyes treated with prednisolone alone. With the exception of the vancomycin alone treatment group at 12 h postinfection, eyes treated at 6 h lost all retinal function within 12 h postinfection. All antibiotic treatments sterilized infected eyes by 12 h postinfection. Treatments containing vancomycin were the only groups that maintained concentrations greater than the MIC for B. cereus when measured at 12 h postinfection. The addition of prednisolone to the vancomycin treatment group significantly increased the intravitreal and aqueous humor concentrations of vancomycin but did not reduce ocular inflammation when compared to antibiotic treatment alone.
Conclusions: :
Early intravitreal injection of antibiotics improved the therapeutic outcome of B. cereus endophthalmitis. The addition of prednisolone to antibiotics did not provide a comprehensive therapeutic benefit over those antibiotics used alone. This study further demonstrates the critical importance of early therapeutic intervention in the treatment of B. cereus endophthalmitis.
Keywords: bacterial disease • endophthalmitis • antibiotics/antifungals/antiparasitics