ARMOR study: data sheds light on antibiotic resistance in ophthalmology

Penny Asbell, MD, FACS, MBA, discussed data from the ARMOR study with the editors of Modern Retina™ at AAO 2021. The ARMOR study is a 10-year nationwide study examining in vitro antibiotic resistance among isolates that have been collected from ocular infections. The data sheds light on the effects of antibiotic resistance while treating ophthalmic infections, such as endophthalmitis.

The Antibiotic Resistance Monitoring in Ocular Microorganisms (ARMOR) surveillance study has identified high levels of in vitro antibiotic resistance among ocular staphylococcal and pneumococcal pathogens, resistance that may affect treatment success.

Penny Asbell, MD, FACS, MBA, is the director of the Hamilton Eye Institute at the University of Tennessee Health Science Center.

Video transcript

So, you know, ophthalmologists, we really like to get a lot of data. We take pictures, we take images, we take measurements. But with infection, we really got to start treating right away. And one of the questions is, what antibiotic should we start with?

So actually the ARMOR study, which is the only surveillance study done in the United States of ocular isolates, is a real good source of information when you're getting started.

So, we collect ocular isolates from over 44 sites and 22 states over the last 10 years. And in this particular study, we looked at isolates that were collected from either the aqueous, or the vitreous, presumably a patient who had serious infections such as endophthalmitis.

And what was most interesting is that nearly 50% of them were staph isolates that were methicillin resistant, so a high level of resistance to methicillin. But equally interesting is those methicillin resistant isolates, over 70% of them were resistant to three or more other groups of antibiotics. So you got to realize resistance is out there.

Now, this is laboratory testing. It's a standardized method. It's not actually clinical. In clinical, you might do a lot better than laboratory test suggests, but you got to start somewhere. It's a really good way of getting some information right off the bat, even while you're waiting for those cultures.

So think about resistance, it's not uncommon, whether it's staph aureus—we didn't see as much with strep pneumonia, and pseudomonas did pretty well, and so did the H. flu. But that staph still is a problem for us with the methicillin and the multi-drug resistance. So keep that in mind when you're picking an antibiotic.

So, you know, we've collected in the ARMOR study over 6000 isolates, and we're starting to try to understand what are the mechanisms of pathogenicity? What makes an isolate more serious than another isolate? And is it actually the isolate itself, or the interaction between the isolate, the organism, and its genetics and the person who gets infected?

So there's a lot of information there and a lot of opportunities to really understand infection more specifically, and maybe have new interventions for treating more effectively. So, we're gonna use that data to the best we can to give us the best information to be able to treat our patients the best way. So stay tuned for ARMOR data, we keep coming. Thank you for listening.

The American Academy of Ophthalmology (AAO) annual meeting was held November 12 to 15 at the Ernest N. Morial Convention Center in New Orleans, Louisiana. The event included Subspecialty Days and a virtual component for remote participation.

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