Ophthalmology · Retinal Vascular Disease
The facts most likely to be tested
Patients present with sudden, painless, monocular vision loss that is typically profound and permanent.
Funduscopic examination reveals a pale, edematous retina with a classic cherry-red spot at the fovea.
The cherry-red spot occurs because the underlying choroidal circulation remains visible through the thin fovea while the surrounding retina is ischemic.
Carotid artery atherosclerosis is the most common underlying etiology, necessitating an urgent carotid duplex ultrasound.
Giant cell arteritis must be ruled out in elderly patients with associated jaw claudication, scalp tenderness, or elevated ESR/CRP.
Immediate management involves ocular massage and anterior chamber paracentesis to dislodge the embolus and lower intraocular pressure.
Retinal artery emboli (Hollenhorst plaques) are often visualized as bright, refractile cholesterol crystals at vessel bifurcations.
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A 68-year-old male presents to the emergency department complaining of sudden, painless loss of vision in his right eye that occurred while eating breakfast. He has a history of hypertension and hyperlipidemia. On physical exam, his visual acuity is light perception only in the right eye. Funduscopic examination reveals a pale, edematous retina with a prominent cherry-red spot at the fovea. His carotid pulses are diminished on the right side.
What is the most likely diagnosis and the most appropriate next step in management?
Central retinal artery occlusion (CRAO); carotid duplex ultrasound.
The presentation of sudden, painless vision loss with a cherry-red spot is pathognomonic for CRAO, which is most commonly caused by carotid artery emboli, requiring urgent vascular evaluation.
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High yield triage
Etiology / Epidemiology
Common in atherosclerosis and carotid artery disease; often embolic in origin.
Clinical Manifestations
Painless, monocular vision loss with cherry-red spot on fundoscopy.
Diagnosis
Clinical diagnosis; fundoscopy is the primary tool for visualization.
Treatment
Immediate ocular massage and anterior chamber paracentesis; time-sensitive.
Prognosis
Permanent vision loss is common; 90% of patients have poor visual acuity.
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Epidemiology & Etiology
Primarily affects patients with hypertension, diabetes, and atrial fibrillation. Emboli from the carotid artery are the most frequent cause. Giant cell arteritis must be ruled out in patients over 50.
Pertinent Anatomy
The central retinal artery is the primary blood supply to the inner retina. It is an end-artery, meaning there is no collateral circulation to compensate for acute obstruction.
Pathophysiology
Acute occlusion leads to retinal ischemia and edema. The cherry-red spot occurs because the fovea is thin and receives blood from the underlying choroid, which remains perfused while the surrounding retina turns opaque/white.
Clinical Manifestations
Patients present with sudden, painless, monocular vision loss. Fundoscopy reveals a pale, edematous retina with a cherry-red spot at the fovea. Afferent pupillary defect is a hallmark sign of severe ischemia.
Diagnosis
Diagnosis is clinical via fundoscopy. If giant cell arteritis is suspected, obtain an erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) immediately. Do not delay treatment for imaging.
Treatment
Immediate ocular massage is performed to dislodge the embolus. Anterior chamber paracentesis may be used to lower intraocular pressure. Avoid thrombolytics unless within the narrow window and under specialist guidance.
Prognosis
Irreversible retinal damage occurs within 90-100 minutes of total occlusion. Long-term management focuses on secondary prevention of stroke and cardiovascular events.
Differential Diagnosis
Central Retinal Vein Occlusion: characterized by blood and thunder fundus appearance
Retinal Detachment: presents with curtain coming down and flashes/floaters
Amaurosis Fugax: transient vision loss lasting minutes, usually due to carotid emboli
Giant Cell Arteritis: associated with jaw claudication and elevated ESR
Ocular Migraine: transient visual disturbances with normal fundoscopic exam