Multidrug-Resistant Organisms from Ophthalmic Cultures: Antibiotic Resistance and Visual Acuity

There is a growing trend of multidrug-resistant organisms (MDRO). The goal of this study was to characterize MDRO at a single center from ophthalmic cultures to better understand how treatments were tailored and to assess effect on visual acuity.

The MDRO data were collected by the Multidrug-Resistant Organism Repository and Surveillance Network from the Brooke Army Medical Center clinical laboratory. Both patient- and isolate-specific data were collected and qualitatively analyzed. Primary outcome measures were organism and type of resistance, anatomic location of isolate, initial and final antibiotic choice, and visual acuity.

Thirty-one bacterial culture samples were analyzed from 29 patients. Twenty-two (72%) were Gram-positive and all were methicillin-resistant Staphylococcus aureus (MRSA). Nine (29%) were Gram-negative and of these five were Pseudomonas spp. Fourteen (45%) isolates were cultured from the cornea, nine (29%) from the lid, four (13%) from the conjunctiva, and four (13%) from other locations. The majority (66.6%) required adjustment of initial antibiotics following ocular culture results. Sixteen adult patients had recorded initial and final visual acuities. Fifteen of those 16 patients had stable or improved visual acuities following treatment of the infection, but five patients had a final visual acuity less than 20/200.

This study demonstrated a high frequency of corneal MDRO infections and specifically MRSA and Pseudomonas spp. isolates. Antibiotic treatments frequently required adjustment. Further prospective study of visual outcomes from ophthalmic MDRO cultures is needed.