NEW YORK (Reuters Health) -Thirteen cases of methicillin-resistant Staphylococcus aureus (MRSA) infectious keratitis that arose following refractive surgery are described in the American Journal of Ophthalmology for April.

"This is the first case series of MRSA infectious keratitis following refractive surgery, the first reports of MRSA keratitis after refractive surgery in patients with no known exposure to a healthcare 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," the authors note.

Dr. Eric D. Donnenfield, from Ophthalmic Consultants of Long Island, and colleagues conducted a chart review of refractive surgery cases at 10 practices and identified 12 patients (13 affected eyes) who developed MRSA keratitis after treatment.

Nine of the patients were healthcare workers or were exposed to a hospital surgical setting, the researchers report.

The presenting complaints, noted in all patients, were a drop in visual acuity accompanied by pain or irritation in the affected eye. Findings on slit-lamp biomicroscopy included corneal epithelial defects, focal infiltrates with surrounding edema, conjunctival injection, purulent discharge, and hypopyon, the report indicates.

In all cases, infectious keratitis was diagnosed at presentation and the subjects were treated with two topical antibiotics, one of which was usually vancomycin. Several of the patients required surgical intervention. All of the eyes were culture-positive for infection with MRSA.

"MRSA keratitis is a serious and increasing complication following refractive surgery," the authors conclude. "Patients with exposure to a healthcare environment should be considered at additional risk for developing MRSA keratitis."