Intravitreal vancomycin and amikacin versus intravenous imipenem in the treatment of experimental Staphylococcus aureus endophthalmitis
- 134 Downloads
Background: Controversy still surrounds the intravenous (IV) treatment of endophthalmitis. The purpose of this study was to compare IV and intraocular (IO) treatment in experimental Staphylococcus aureus endophthalmitis: intravitreal injection of vancomycin and amikacin (VA/AN) in comparison with IV imipenem (IPM) and a combination of IV and IO (IV+IO) therapy. Methods: The right eyes of 27 rabbits were injected with 25,000 S. aureus. After 24 h, animals were either treated with IO VA/AN (n=5; 1.0 mg/0.4 mg in 0.1 ml saline), or IV IPM (n=9; 37 mg/kg body weight 3× daily), or IV+IO therapy (n=7), or served as untreated controls (n=6). Clinical appearance was evaluated daily and vitreous aspirates were obtained for bacterial culture 24 h and 6 days after therapy, when the eyes were enucleated for histopathologic examination. Results: Eyes in the IO or IO+IV treatment group had a significantly better appearance clinically and histologically than did eyes in the IV or untreated control group. Eyes in the IO+IV group had a similar appearance to the IO-treated eyes. All aspirates from the IO and IO+IV groups were culture-negative 24 hours after therapy, whereas only five of nine in the IV-treated group were culture-negative. Aspirates from all treatment groups were culture-negative by day 6 after the initiation of therapy. Untreated control eyes were culture-positive at all times. Conclusion: IO therapy with VA/AN proved more effective in treating experimental S. aureus endophthalmitis than did IV therapy with IPM alone. IV+IO treatment was not superior to IO treatment alone.
We thank Begonia Sesma Bea and her staff at the Instituto de Salud Publica, Juan Fernandez de las Casas de la Tejerinera and the personnel at the Unidad de Investigacion Biomedica of the Hospital de Navarra, and Rafael Iturralde at the Department of Ophthalmology, Hospital Virgen del Camino (all in Pamplona, Spain) for providing physical space and technical assistance with the animal work. We are grateful to Helga Treibs at the Laboratory for Histopathology at the University Eye Hospital, Ludwig-Maximilians-Universität, Munich, Germany for technical assistance, and Yin Zhang at the College of Public Health, Oklahoma University Health Sciences Center, Oklahoma City, Oklahoma, USA for help with the statistical analysis.
- 4.Barza M, Baum J, Birkby B, Weinstein L (1973) Intraocular penetration of carbenicillin in the rabbit. Am J Ophthalmol 75:307–313Google Scholar
- 10.El Baba FZ, Trousdale MD, Gauderman WJ, Wagner DG, Liggett PE (1992) Intravitreal penetration of oral ciprofloxacin in humans. Ophthalmology 99:483–486Google Scholar
- 11.Engelbert M, Mino De Kaspar H, Mette M, Thiel M, Ta CN, Grasbon T, Schulze-Schwering M, Klauss V, Kampik A (2003) Intravenous treatment of experimental Staphylococcus aureus endopthalmitis: imipenem versus the combination of ceftazidime and amikacin. Graefes Arch Clin Exp Ophthalmol 241(12):1029–1036CrossRefPubMedGoogle Scholar
- 13.Kasbeer RT, Peyman GA, May DR, Homer PI (1975) Penetration of amikacin into the aphakic eye. Graefes Arch Klin Exp Ophthalmol 196:85–94Google Scholar
- 14.Koul S, Philipson A, Philipson BT, Kock E, Nylen P (1990) Intraocular levels of cefuroxime in uninflamed rabbit eyes. Acta Ophthalmol (Copenh) 68:455–465Google Scholar
- 22.Peyman GA, Schulman JA (2002) Drug therapy for endophthalmitis. In: Peyman GA, Schulman JA (eds) Intravitreal surgery: principles and practice. Appleton and Lange, Norwalk, Conn., pp 100–150Google Scholar
- 25.Rubinstein E, Triester G, Avni I, Schwartzkopf R (1987) The intravitreal penetration of cefotaxime in man following systemic and subconjunctival administrations. Ophthalmology 94:30–34Google Scholar
- 26.Sakata Y, McCracken G H Jr, Thomas ML, Olsen KD (1984) Pharmacokinetics and therapeutic efficacy of imipenem, ceftazidime, and ceftriaxone in experimental meningitis due to an ampicillin- and chloramphenicol-resistant strain of Haemophilus influenzae type b. Antimicrob Agents Chemother 25:29–32PubMedGoogle Scholar
- 27.Shaarawy A, Grand MG, Meredith TA, Ibanez HE (1995) Persistent endophthalmitis after intravitreal antimicrobial therapy. Ophthalmology 102:382–387Google Scholar
- 29.Sorsby A, Ungar J (1948) Distribution of penicillin in the eye after injections of 1,000,000 units by the subconjunctival, retrobulbar and intramuscular routes. Br J Ophthalmol 32:864–877Google Scholar