Abstract
Purpose: :
To investigate the antibiotic sensitivities and visual acuity (VA) outcomes of culture proven methacillin–sensitive (MSSA) versus methacillin–resistant (MRSA) Staphylococcus aureus endophthalmitis.
Methods: :
A retrospective, consecutive, case series of all patients with culture proven Staphylococcus aureus endophthalmitis seen at the Bascom Palmer Eye Institute from January 1, 1995 – July 1, 2005 were reviewed for antibiotic sensitivities, VA at presentation and at subsequent intervals. Polymicrobial cases were not included.
Results: :
This study examined 28 cases of Staphylococcus aureus endophthalmitis (17 MSSA, 11 MRSA) in 28 patients. The etiologies were cataract surgery 16/28 (57%), endogenous 5/28 (18%), bleb–associated 3/28 (11%) and miscellaneous 4 (14%). All isolates were sensitive to vancomycin. MSSA was greater than 94% sensitive to all tested antibiotics, except penicillin, while increasing resistance was detected in the MRSA isolates. The MRSA group exhibited statistically significant reduced sensitivities to both older generation fluoroquinolones (ocufloxacin 4/11 [36%] and ciprofloxacin 5/11 or [45%]) was well as the newer fourth generation fluoroquinolones (moxifloxacin 5/11 or [45%] and gatifloxacin 5/11 or [45%]). The median presenting VA was hand motion range for both MSSA and MRSA cases. A VA of 20/400 was seen in 57% of MSSA cases and 40% of MRSA cases at three months. Overall, logMAR VA outcomes after treatment for MSSA and MRSA isolates were statistically similar at time intervals of one month (p=.83) and three months (p=.88).
Conclusions: :
In the current study, MRSA isolates were more likely to exhibit resistance to a wide variety of antibiotics including the fourth generation flouroquinolones. VA outcomes showed no statistically significant differences between MRSA and MSSA groups after 3 months of follow–up.
Keywords: endophthalmitis • Staphylococcus • antibiotics/antifungals/antiparasitics