Researchers reported the first cases of Methicillin-resistant Staphylococcus aureus (MRSA) found in 12 patients (13 eyes) following refractive surgery in the April issue of the American Journal of Ophthalmology.
These cases, they say, represent several other firsts: the first reports of MRSA keratitis after refractive surgery in patients with no known exposure to a health-care facility, the first report of MRSA keratitis after a laser in situ keratomileusis (LASIK) enhancement, and the first reports of MRSA keratitis after prophylaxis with fourth-generation fluoroquinolones.
In this study, a multicenter chart review, nine of the 12 patients were either health-care workers or exposed to a hospital surgical setting. All patients presented with decreased visual acuity and pain or irritation in the affected eye. Slit lamp findings included corneal epithelial defects, focal infiltrates with surrounding edema, conjunctival injection, purulent discharge, and hypopyon.
MRSA, a serious postoperative complication, has been found in many health-care settings. Colonization of MRSA has been found in 1.5% of the general population, but as many as 9.4% of those were exposed to a health-care facility.
Also, strains of MRSA are emerging in communities. These so-called community strains tend to be resistant only to beta-lactam antibiotics, unlike the hospital strains, which usually demonstrate multiple drug resistance. Community-acquired MRSA is becoming a significant problem; the prevalence of MRSA among community isolates is expected to reach as high as 25% in the next decade.
All 12 patients reported in this study were diagnosed with infectious keratitis on presentation and treated with two antibiotics.
MRSA infectious keratitis is a potentially serious complication following refractive surgery, writes Eric D. Donnenfeld, M.D., one of the studys authors. Health-care workers may develop keratitis from microbes associated with nosocomial infection. In addition, surgeons should now be vigilant for community-acquired MRSA keratitis.
Dr. Donnenfeld recommends informing patients of the risk factors and warning signs of infectious keratitis and advising them to seek medical attention immediately if they develop signs or symptoms of infectious keratitis.
A high degree of suspicion, coupled with prompt and appropriate treatment, may result in improved visual recovery," he says.
Solomon R, Donnenfeld ED, Perry HD, et al. Methicillin-resistant Staphylococcus aureus infectious keratitis following refractive surgery. Am J Ophthalmol 2007 Apr;143(4):629-34.