 All right. I'm going to introduce our first speaker, Dan Abenroth. He comes to us from the neurology department. I can just finish his neurology rotation. I was taught to be with him for the last week. He was really helpful in showing me the ropes. And he is, in his last year of his residency and headed to Medical University of South Carolina for a stroke fellowship next year. And he's going to talk just about an interesting case he saw while he was on neurology. Thank you for having me here. So this case, I'm going to put special emphasis on how we, as a stroke service, and you guys, as the ophthalmology team, can work together to help this subset of patients that have retinal artery occlusion and as it relates to stroke and how we can collaborate with these patients together. Starting, I wish to present the case. We'll call her Mrs. X. She's an 82-year-old female who presented to our service with acute onset of left eye vision loss. This was painless, and its onset and sudden happened on the 25th of January. She waited for about two days until she saw her primary ophthalmologist. He was very concerned by what he saw and placed an urgent referral to be seen by a retinal specialist at a fear of coroidal neovascular membrane. She saw the retinal specialist the next day. He noted an afferent pupillary defect was also very concerned by what he saw and placed an urgent referral to be seen in our neuroophthalmology clinic. And she was seen that same afternoon. Her past medical history is really just notable for hypertension and hyperlipidemia. Her social history and family history are otherwise unremarkable. On examination, her visual acuity, OD, was 2020. On the left, she was 2100. And you can see her Humphrey visual fields here to the left showing quite significant visual field defects. We confirmed that she did, in fact, have a left APD. Her extracurricular movements, her intraocular pressure and anterior chamber examination were all essentially normal. Her phonoscopic exam certainly caught our attention. She had retinal edema along the inferior arcade with an apparent aberrant blood vessel just outside that arcade. And it seemed to us that she had psyllial retinal artery sparing in that region following that artery. However, she has baseline age-related macular degeneration. And this made her evaluation somewhat complicated because the typical phonoscopic exam findings of a retinal artery occlusion, namely retinal opacities, macular pigment changes, and a cherry red spot, were not evident because of her baseline degenerative changes. Consequently, by examination and history alone, we could not reliably diagnose her with her retinal artery occlusion, though we were suspicious of such. Optical coherence tomography proved to be extremely useful in this instance. I have shown right now her OCT from May 2015. And what I want to bring your attention to is that she has significant baseline macular thinning bilaterally, which you can see in her images as the areas of blue showing significant areas of thinning. Here is her OCT that was obtained shortly before we saw her. On the left of your screen showing her right OCT, there was little change. On the right of your screen showing her OCT from the left, however, you'll see that there are changes in her macular thickness. Areas that were once blue are now appearing more yellow, indicative of increased thickness. We would not expect a person with macular degeneration to have normalization in this regard. This struck us as abnormal, and we were suspicious that this was more indicative of edema from a vascular ischemic event. And I've highlighted that change for you so you can bring your eyes to it. Another area where you can see the change are the images at the bottom of the screen. The dark image shows that there has been little increase in macular thickness. The image of red, the red areas specifically, show the actual incremental change from May until January. Areas of red are at the highest level of scale change that we can have in this testing. Shown again, you can see the significant areas of edema for the patient's left macula. Given this prominent change, to us this was the strongest evidence we had in our office that day that she indeed did have a central retinal artery occlusion. I've attached another picture. We wanted to get imaging, excuse me, photography of her own eye, which we weren't able to obtain. But shown is silkyluretinal sparing, which we would expect to have seen in photography to show you today how we obtained it. This is a different patient, but this is classic for patients with that type of sparing. We notified the stroke team immediately at the university, explaining to them that we believe this patient had had a central retinal artery occlusion, requested admission to their service, which they accepted. And the patient was brought into the hospital that night. Her hospitalization was routine as it relates to workup for a stroke patient. She underwent brain MRI, CT angiogram of the head and neck, as well as transthoracic echocardiogram. Her CTA of head and neck was largely unremarkable. She had mild atherosclerosis, but nothing severe. Her MRI of the brain, however, was quite interesting. And I'll spend a moment talking some of our typical imaging sequences that we use. Shown is what is called the diffusion-weighted image. This is the imaging sequence we used most commonly for evaluating acute ischemia. For a patient that has an acute ischemic event, changes can be seen really within minutes. And these changes are apparent on this imaging sequence for upwards of 14 to 20 days. As you can see, the patient has several ischemic hits in different vascular territories. These findings were enough for the stroke team to diagnose her with a multi-territorial cardio-embalic infarct. Specifically, these infarcts are in the right in MCA territories, and there are some that are approaching the PCA territories. Though we're not able to capture atrial fibrillation during her hospitalization, the assumption is that she has paroxysmal atrial fibrillation and was started on Coumadin. A few diagnostic pearls that we can glean from this case are first that in a retina that's already thin from macular degeneration, one should be careful to not be fooled by the absence of typical retinal artery occlusion findings that you would expect to see. Second, OCT in these instances can be a useful adjunct in the evaluation of these patients. In a study of 134 patients with central retinal artery occlusion, it was shown that those with a more severe grade of retinal artery occlusion had more significant edema on OCT. If one sees pseudonormalization like we did, one should have a high suspicion that this is representative of an ischemic event. I wish to spend a few minutes, however, focusing on, from my perspective, what I really wanna hammer home today for this, and that is the association between retinal artery occlusion and stroke. Central retinal artery occlusion has an incidence of about one to 100,000. Of these patients, 24% are expected to have some sort of ischemic event to their brain. Now this 24% includes both those who have branched retinal artery occlusions as well as central retinal artery occlusions. We don't have the data, but the assumption is that those with central retinal artery occlusions probably have an even higher incidence of associated stroke. The stroke patterns typically show multiple small infarcts, exactly what our patient showed on her MRI. Furthermore, for those patients who undergo comprehensive stroke evaluation for a central retinal artery occlusion, upwards of 80% will have a previously undiagnosed significant vascular risk factor that is discovered during their stroke evaluation. 40% of these can be critical artery, critical carotid artery stenosis. I myself have had several patients in this instance that required CEA after their retinal event. It's of no surprise that with these statistics, the American Heart Association and the American, excuse me, and the National Stroke Association both recommend that for patients with retinal artery occlusion undergo an urgent evaluation for a stroke. Yet in a study in which ophthalmologists were pulled in the south, how often they send patients with retinal artery occlusion for urgent evaluation, only about 35% of ophthalmologists do. Suggestive that many just underestimate the likelihood of associated stroke being found and really the potential danger of this. The Moran and the University Stroke Team, however, are very aware of this and have collaborated together to create a protocol to help ophthalmology providers as well as stroke providers have more direction and clarity as to how to approach these patients and how we can work together to minimize the risk of future stroke, future retinal artery occlusions, disability, and worst case scenario, death from a stroke. This protocol was established in January 2015 after collaboration between both services. For patients who have had a retinal artery occlusion within seven days, the protocol is quite simple. All you need to do as an ophthalmologist is pick up the phone, call the transfer center, and ask to speak to the stroke attending and explain to them what you have found on exam. The expectation, and in the vast majority of cases, the patient will just be directly admitted to the hospital for an urgent evaluation as was the case for our previous patient. For those who have had a retinal event more than seven days before you've seen them in clinic, an office evaluation is appropriate, of course, depending upon the clinical circumstance and how they look. An MRI of the brain should just be ordered immediately without contrast, and in the directions one can just type stroke protocol and the radiologist will know what to do with that. Vessel imaging should be obtained. There's several different modalities you can use for that. You can use CT angiogram of the head and neck, which is what we use most commonly on the stroke service. MRA is also acceptable and is often more convenient for the patient since you're already sending them for an MRI of their brain. The advantage of MRA as well is that if you have a patient that can't tolerate contrast, you can use a different sequence called time of flight, which does not require contrast but can show the vessel imaging quite well. Carotid duplex is also acceptable, though does not evaluate vertebral arteries, which is less applicable in this instance, however, since the alphalmic does not branch off through vertebrals. Trans thoracic echocardiogram should also be obtained. We're commonly asked, if I'm ordering a TTE, should I order it with bubble study? That is subject to debate. For this protocol, age 55 is the cutoff that if your patient is younger than that age, you should go ahead and order it with bubble. Routine labs of lipids, hemoglobin A1C, ESR, and CRP should also be ordered. And if there's no contraindications for the patient to start, these medicines, aspirin 81 milligrams and atorvastatin should be started immediately. And then the stroke service should be notified so we can try to bring the patient into our clinic within one week. Now this might seem like a lot and down the road when you forget everything I've told you and you remember that there was a lecture once about this protocol and you don't wanna put these orders in or uncomfortable or uncertain what orders there are, I've spoken with the neuro-optimology team and they have agreed that you can easily contact them and they can help guide you through these orders. In summary, it's important to remember that the typical exam findings of retinal artery occlusion can be missed in patients with pre-existing macular degeneration but that OCT can be a useful adjunct and that pseudonormalization can be a warning sign that an ischemic event has occurred. As one going into stroke neurology, I can't emphasize enough that these patients are absolutely at risk of stroke if they haven't already had concomitant strokes with the retinal artery occlusion and that they are certainly at high risk of having more of them and that as stroke neurologists, these are patients we are very eager to take on to our service and evaluate and to make everyone's lives easier, just remember that there is a protocol for this and all you need to do is just go to Pulse on the university website, type in retinal artery occlusion and it's one of the first things to come up and it will guide you through exactly what needs to be done or if that's too much to simply contact the stroke team or the neuro-optimology team and they can guide you through this process. Are there any questions? Yes, Dr. Katz. So Dan, I just wanted to emphasize that our patient with those strokes that she had were asymptomatic, right? They were asymptomatic. The only symptoms she had were with her eye. So an examination alone, a normal neuro-exam is not enough to exclude stroke. Though certainly if you see focal deficits that are new that should raise your suspicion and the urgency of being evaluated. Yes? So is the lack of introverted relation enough to assume she had it to put her on Coumadin just because she had this? It is. It is common for our patients when we see a multi-territorial stroke that's in different vascular territories, bilateral MCAs or an MCA in a PCA territory, what we will do routinely is start them on Coumadin and then send them home on a 30-day cardiac event monitor. There is some differences between providers. Some stroke neurologists will hold off until they get more information from the 30-day event monitor but most of the stroke neurologists will just preemptively start them and then potentially pull off down the road if they feel that the evidence for AFib is lower but most would rather just start. Other questions, yes? Question seven. I remember it was a 24% patients area will have some sort of findings on it. It's 24% of any retinal artery occlusion. Whether that's branch or central will have an associated stroke at the time of their evaluation, yes? The two brain on central's higher than the brain. So I guess my question is, I do think of this, of course, as a policy that it actually surprises me in a way that it's that low. I would expect it to be higher. And we don't have the data for central retinal artery occlusion but as Dr. Katz said, it's certainly anticipated to be higher than 24%. In the literature, many approach these as a TIA-like event which I think is actually under-judging the significance of this event because this is just a Frank ischemic event as opposed to a TIA being a temporary one but many will clump it into that. Using this as a very strong warning sign that if they haven't had a stroke yet within days they could have more significant ones. Yes, Dr. Warner? So a couple of things. Number one, I think a bit of follow-through on this, Jen Majersic, who's a stroke neurologist who we were working with to develop protocol says that about once a month she'll see a patient who has now been admitted under similar type of protocol because patients sometimes go directly to the emergency room and not the protocols kind of get going. It doesn't have to necessarily come through the grant and it has been extremely helpful. And she also commented on her own patient who had had a branch retinal artery occlusion in one eye, didn't get evaluated for it, had a branch retinal artery occlusion in the other eye and is now no longer able to work because he was a driver and can't drive. So very, very effective protocol. Just to remind you, Jeff, an answer to the question that 24% of patients have had a recent asymptomatic stroke on their MRI scan. And that means that within the last 21 days there had been something else. That doesn't speak to whether or not there had been strokes prior to that, maybe 30 days. You might not see that on DWI. Number one, and number two, that also doesn't tell you what's gonna happen next week. And then specifically with regard to the implementation of the protocol that's after seven days. Yes, it's all on the website, et cetera, et cetera, but I think that the most important thing is to contact the stroke neurologist and they will take it from there. Okay, if you say to the stroke neurologist, this patient has to be RAO, if it was less or CRAO, if it's less than seven days, it will admit them to the hospital, if it was more than seven days, they will take care of it. So it's important to know all that stuff and it's important to know where to get the information, but the most important information is to call stroke neurology. They are on call 24-7, and they will take care of that huge evaluation. You don't have to worry about it. Yeah, this evaluation for us is bread and butter, pretty easy stuff that we're doing routinely. It's pretty much a pre-printed protocol. Yeah, we could do this in our sleep. So, yes. They actually are. It works just as well if they're asleep, really. So finally, with regard to the atrial fibrillation, there's a very, very interesting body of literature coming out suggesting that the findings that you're actually seeing on echocardiogram, maybe an enlarged left atrium, a bit of scarring in the left atrium that you can see on MRI of the heart, not that's investigational, but it is not actually the atrial fibrillation itself, it's the sixth atrium that puts a patient at risk of embolic disease. So, some stroke neurologists, even if the 30-day event monitor is negative, with this kind of situation with multiple stroke, we'll still put a patient on enteroagulation, not just aspirin, incredibly important life-saving. I'm gonna cut off the discussion at this point, so we don't short Dr. Huang. Thanks, Dan. Thank you for your time.