A 50-year old man with atrial fibrillation and off of warfarin for the past 6 months comes to you with many complaints. But the one that catches your eye (pun intended. zing!), is that he complains of blurry vision.
1. What is the single most important test you must do on this patient?
2. Spoiler Alert: once you suspect central retinal artery occlusion, what can you do about it and how likely is the patient to improve?
3. What’s the pathophysiology and risks for this condition?
Let’s answer the questions in REVERSE.
3. Central retinal artery occlusion is an embolic event that reaches the ophthalmic artery which is the FIRST branch off of the internal carotid. Risks include age (50-70 most commonly), hypertension, coronary artery disease, collagen vascular disease, and sickle cell disease.
2. Management of central retinal artery occlusion is challenging because often the vision loss is not reversible. Treatment strategies may include the following (often unsuccessful) interventions: Call ophtho. It’s a true emergency and it may need ocular paracentesis (though may be of “little benefit”). In the meantime, you may attempt globe massage (10-15s at a time); meds that decrease intra-ocular pressure (acetazolamide or 0.5% timolol); “Carbogen” (a mix of 95% oxygen and 5% carbon dioxide, also “little benefit”.); possibly even thrombolytics (very sketchy data on this). Time is eye, if you’re lucky. Around 25-30% will improve regardless of these treatments. The rest will not improve or worsen, regardless of these treatments. (Point of discussion: so maybe just call ophtho and skip the rest? Unclear in the community on this one.)
1. You must do a SNELLEN test of visual acuity. There are many smart phone apps for this in addition to large SNELLEN charts in the ED.
Sharma and Brunette in: Rosen’s Emergency Medicine, Chapter 71, 909-930.e2.
Squizzato A, Manfredi E, Bozzato S, Dentali F, and Ageno W: Antithrombotic and fibrinolytic drugs for retinal vein occlusion: A systematic review and a call for action. Thromb Haemost 2010; 103: pp. 271-276
Atebara N, Brown GC, and Cater J: Efficacy of anterior chamber paracentesis and carbogen in treating nonarteritic central retinal artery occlusion. Ophthalmology 1995; 102: pp. 2029-2038
Rudkin AK, Lee AW, Aldrich E, Miller NR, and Chen CS: Clinical characteristics and outcome of current standard management of central retinal artery occlusion. Clin Experiment Ophthalmol 2010; 38: pp. 496-501
Rumelt S, and Brown GC: Update on treatment of retinal arterial occlusions. Curr Opin Ophthalmol 2003; 14: pp. 139-141