A 10-Year Review of Ocular Methicillin-Resistant Staphylococcus aureus Infections: Epidemiology, Clinical Features, and Treatment.

PURPOSE: To characterize epidemiological data on methicillin-resistant Staphylococcus aureus (MRSA) ocular infections over a 10-year period in Hong Kong; to compare the characteristics between hospital-associated methicillin-resistant Staphylococcus aureus (h-MRSA) and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) ocular infections; and to review the treatment regimen and outcome of identified cases.

METHODS: A retrospective case review of ocular samples testing positive for MRSA at a tertiary eye center from July 2005 to June 2015 was performed.

RESULTS: Ninety nonduplicative samples from 75 patients with ocular MRSA infection were included during the study period. The average annual rate of ocular MRSA infection among all ocular S. aureus infections was 12.9%. Ten patients had CA-MRSA (13.3%). The most common clinical manifestation was preseptal cellulitis in the CA-MRSA group and blepharoconjunctivitis in the h-MRSA group. Vision-threatening conditions occurred only in the h-MRSA group. Besides vancomycin, other antibiotics to which both MRSA groups were highly sensitive included chloramphenicol, fusidic acid, cotrimoxazole, and gentamicin. Significantly more CA-MRSA was sensitive to levofloxacin and clindamycin (P < 0.01). The h-MRSA group required a significantly longer duration of treatment to eradicate infection (mean 79 vs. 28 days, P < 0.01).

CONCLUSIONS: CA-MRSA presents as a genetically different organism with distinctive clinical presentation and antibiotic sensitivity from its h-MRSA counterpart. Despite increasing resistance patterns, we demonstrate that MRSA ocular infections can be effectively treated without the use of vancomycin, limiting its use to refractory or vision-threatening conditions.