||Andrew G. Lee, MD, Chairman, Department of Ophthalmology, The Methodist Hospital, Houston, TX, Professor of Ophthalmology, Weill Cornell Medicine; Johnathan Go, Baylor College of Medicine, Class of 2021
||Summary: • We discussed two different strokes in the eye o Optic Nerve Stroke: Non-arteritic anterior ischemic optic neuropathy (NAION) o Retina Stroke: Central retinal artery occlusion (CRAO) • Approach to CRAO o CRAO is a stroke! o Urgent Stroke Work-Up: Call Stroke Team, Send to Stroke ER, and Stroke Work-Up (carotid doppler, EKG, etc.) -If needed, you can give the patient a note that says, "I have had a stroke in my optic nerve/retina, and I need to have a stroke work-up" -Do not send them to a PCP or cardiologist. Time is brain and retina! o Thrombolytic Therapy (tPA) -Prior European studies (e.g. EAGLE trial) have concluded that tPA is not effective for CRAO. However, these studies did not administer the tPA during the standard 4.5-hour window. -Most patients do not present to you soon enough to be within the tPA time frame; If they do arrive within the window, you should strongly consider administering tPA -Ultimately, it will likely be the stroke team's call on the administration of tPA • Approach to NAION o Giant Cell Arteritis Work-Up: Sedimentation Rate and C-Reactive Protein (CRP) [Transcript of video] "So, we talked about Central Retinal Artery Occlusion previously, in terms of arteritic vs. non- arteritic, and today, we're going to talk about "CRAO is a stroke of the eye". And what we mean by that is, we have to act emergently in terms of working it up, because if you have a stroke in your eye, you can get a stroke in your brain, and there's a window of opportunity that most people would not use for thrombolytic therapy, because most people don't come in in time for a CRAO to be treated with thrombolytic therapy. And there have been several studies including the EAGLE trial in Europe that showed thrombolytic therapy didn't work. However, all of the trials have had the same fundamental flaw, which is, they weren't within a 4.5 - or whatever window you've chosen - hour for the administration of tPA. The important part for an ophthalmologist is - there's been a paradigm shift in the way the stroke literature is looking at central retinal artery occlusion, so central retinal artery occlusion is now considered a stroke of the eye. And that means we have to call the stroke service. So, if we see a CRAO, we should call the stroke team, we should be evaluated in the stroke ER, and we should have a stroke work-up, because time is brain, but time is also retina, and retina is also brain. So, the next time you see a central retinal artery occlusion, the main thing we're looking for is, "Is it a stroke?" and "How long's it been there?". If it's been there within the tPA window, we would probably refer urgently to the stroke team and the stroke work-up, and it's up to the stroke team to decide whether or not they would give the thrombolytic therapy. If they're outside the tPA window, we still have to call the stroke team and we have to use the stroke emergency room, but you're going to give the patient a note that says, "I have had a stroke in my optic nerve or my retina, and I need to have a stroke work-up." As you know, the stroke in the optic nerve is NAION, non-arteritic anterior ischemic optic neuropathy, so the stroke in the optic nerve does not need to go to the ER, does not need to have the carotid doppler, does not need to have the echocardiogram. All they need is to have a sed rate and CRP. And so, if you can do that in your own office, then you didn't even have to send that patient to the stroke center. So, we need to make a differentiation between stroke in the optic nerve and stroke in the retina. Stroke in the retina needs the stroke work-up. Stroke in the optic nerve only needs to have the giant cell work-up. So, the paradigm shift for central retinal artery occlusion: It's a stroke, a stroke of the eye. If it's a stroke in the eye, you have to call the stroke team and have them worked up in the stroke ER for a stroke. And you need to do that fast. You can't send them to the PCP, or send them to the cardiologist. That needs an urgent work-up if it's an urgent stroke. And if you're in the tPA window, make sure they at least get a chance at thrombolytic therapy."