Bactericidal effect of intravitreal levofloxacin in an experimental model of endophthalmitis. Issue 5 (22nd January 2008)

• Record Type: Journal Article
• Authors: Ferrer, C; Rodríguez, A; Abad, J L; Fernandez, J; Alió, J L
• Is Part Of: British journal of ophthalmology. Volume 92:Issue 5(2008)
• Page Start: 678
• Page End: 682
• Publication Date: 2008-01-22
• Subjects: Ophthalmology -- Periodicals; 617.7
• DOI: 10.1136/bjo.2007.124768
• Languages: English
• ISSNs: 0007-1161

Abstract

Abstract : Aim: To evaluate the efficacy of intravitreal 1.5% levofloxacin versus combined treatment with vancomycin and ceftazidime in an experimental model of bacterial endophthalmitis. Methods: The right eye of 75 New Zealand White rabbits was inoculated in the vitreous cavity with strains of Staphylococcus epidermidis, Staphylococcus aureus or Pseudomonas aeruginosa . The study evaluated treatment with 1.5% levofloxacin compared with 1% vancomycin plus 2.2% ceftazidime, and a control group. At 24 h after treatment, 100 μl vitreous and aqueous humor were harvested, and the number of colony-forming units (CFU) per ml was determined. The microbiological status of the vitreous and aqueous humor samples was tested at day 2, 3, 5 and 8. The Peyman classification was used to assess the severity of endophthalmitis. Results: For the S epidermidis endophthalmitis model, levofloxacin treatment produced an approximately 3 log decrease in CFU/ml of vitreous relative to that in untreated eyes (p = 0.023), whereas vancomycin plus ceftazidime produced a 5 log reduction in CFU/ml (p = 0.023). However, in the S aureus model, levofloxacin treatment produced an approximately 4 log reduction in CFU/ml, whereas vancomycin plus ceftazidime produced an approximately 2 log reduction in CFU/ml relative to that of the control (p = 0.018 and p = 0.019, respectively). Treatment of P aeruginosa -infected rabbit eyes with levofloxacin produced a 5 log reduction in CFU/ml of vitreous, whereas vancomycin plus ceftazidime produced an approximately 3–4 log reduction in CFU/ml relative to that of the control (p = 0.001). However, there was no significant difference between levofloxacin and vancomycin plus ceftazidime on comparing the reduction of CFU/ml of vitreous for any of the bacterial strains studied. Conclusions: Levofloxacin appears to be effective in treating experimental endophthalmitis in the rabbit model. Further studies, especially on the toxicity of intravitreal levofloxacin, are required before a clinical role for the drug in postoperative therapy can be determined.