Endophthalmitis caused by Staphylococcus epidermidis:: In vitro antibiotic susceptibilities and clinical outcomes

BACKGROUND AND OBJECTIVE: To investigate the antibiotic sensitivities and clinical outcomes of eyes with endophthalmitis caused by methicillin-sensitive versus methicillin-resistant Staphylococcus epidermidis (MSSE/MRSE). PATIENTS AND METHODS: A retrospective, consecutive case series of all patients with endophthalmitis caused by S. epidermidis from January 1, 1996, through July 1, 2004, was conducted. The antibiotic sensitivities and clinical outcomes were obtained from the corresponding medical records. RESULTS: The study included 86 eyes of 86 patients with S. epidermidis endophthalmitis (34 MSSE and 52 MRSE). Endophthalmitis categories included cataract surgery (58), glaucoma surgery (12), trauma (7), vitrectomy (4), penetrating keratoplasty (4), and corneal suture ulcer (1). In vitro testing revealed that all MSSE and MRSE isolates were sensitive to vancomycin, 67% of MSSE isolates and 67% of MRSE isolates were sensitive to gatifloxacin, and 73% of MSSE isolates and 67% of MRSE isolates were sensitive to moxifloxacin (overall 68% sensitive). All eyes were treated with intravitreal vancomycin and either ceftazidime or amikacin. Visual acuity improved to a median of 20/80 at 3 months and 20/60 at 1 year. CONCLUSIONS: In the current study, all MSSE and MRSE isolates were sensitive to vancomycin and 68% were sensitive to the fourth-generation fluoroquinolones. There were no significant differences in visual acuity outcomes of endophthalmitis caused by MSSE versus MRSE isolates.