AAO 2023: New results from ARMOR study shed light on ocular infections

Penny Asbell, MD, FACS, spoke with Ophthalmology Times about her poster on results from the ARMOR Study and latest diagnostic and therapeutic advancements in ocular infections at this year's American Academy of Ophthalmology meeting.

Video Transcript

Editor's note - This transcript has been edited for clarity.

Penny Asbell, MD, FACS:

Hi. You know, what could be worse? An eye infection, something we all dread, and we definitely want to treat right away. So the ARMOR study is a surveillance study done in the United States. And we take that data and we look at antibiotic resistance. So we've looked at isolates from 2009 to 2022. We have 370 isolates from either an aqueous sample or vitreous sample to analyze.

What did we find out? Staph aureus, and coagulase-negative staph, which includes staph epidermidis, lots of resistance, specifically methicillin resistance, it's over 40%, when you look over that time period. Okay, the other important thing is, not only do you see a lot of resistance, methicillin resistance, but if you take those isolates, and then look at other antibiotics, over three-quarters of them are resistant to multiple antibiotics, so it's gonna make it hard to pick the right antibiotic to get going. And that's one of the reasons that ARMOR can be useful. If you look at the MIC data, which is a laboratory data of potency, you see one good news: vancomycin seems to be pretty good from 2009, all through 2022. The other good news is one of the commercially available antibiotics, besifloxacin, seems to be pretty good too, during that same period, so we have some options. But the one thing to think about is, if you see serious infection, get a culture. And then you have to figure out how to get started with treatment, and that's where the ARMOR surveillance study can be really useful.

Surveillance studies tell us a little bit about what's going on. So we stay up to date on treatment, and can get started. And then we can modify or change depending on our culture results. So hopefully, you'll take a look at the ARMOR results that are available publicly, and you can figure out how to get going and make sure those infections get treated right away. And of course, decrease the likelihood if possible, as well.

We know why infections can't wait. We want to treat them right away. And we want to pick the best treatment almost immediately. One of the things that the ARMOR has showed us is, what is the antibiotic resistance pattern? It's that surveillance studies, it's been done year after year from 2009 through 2022. And with that data we've been able to develop what are the resistant trends over a period of time.

So first question is, why is antibiotic resistance so important? I think there are two take homes there. One, the more antibiotics we use, the more resistance we get. And two, we're really not seeing a lot of new antibiotics being created. So we got to make the best use of the ones we have. Now some people say, "Hey, this is a global problem, but is it really an eye problem?" Well, unfortunately, 2023 has definitely told us that antibiotic resistance is an ophthalmology eye problem as well.

In February, we had the Pseudomonas outbreaks from artificial tears. And just this month, in October 2023, we have the FDA telling us about other artificial tears, over 20 different brands, that might be a risk for eye infection. And on top of that, also in October 2023, a publication of what's becoming more and more popular, bilateral simultaneous cataract surgery, believe it or not, three patients, six eyes, bilateral endophthalmitis. And four out of those six were caused by staph, coagulase negative staph epidermidis, which was resistant to moxi and some of the other antibiotics that we typically use.

So what has ARMOR shown us? Well, the staph infections, almost 40% of them, depending on what year you look at, are resistant to methicillin. And what's equally important, if they're resistant to methicillin, they may be multidrug resistant. In fact, over three quarters of them, those have had a methicillin-resistant are also resistant to other antibiotics, three or more other antibiotics tested. That makes it kind of difficult to pick your correct antibiotic to be used. Of course, you're gonna get a culture and eventually that'll give you information on what to do. But you've got to get started right away. And that's where ARMOR can help when you can't wait. You can take a look at the ARMOR studies. We've seen over this period of time for the staph infections, that vancomycin has been really good, whether it's methicillin resistant or not. An interesting one of the commercial preparations, besifloxacin, has also been very good over this long time period.

Well, there is some good news here. Resistace trends have decreased over time. We're not down to anything real low, but they are decreasing. But you know, it's a little bit like blood pressure. We don't take it once and say it's normal and never look at it again. Surveillance studies give us trends over time, help us stay above the curve, stay on top of the curve and offer the best treatment to patients, public health advice and even research information. So take a look at ARMOR, the information is public, and it hopefully will help you get started treating your patients when time can't wait.