Central Retinal Artery Occlusion Flashcards
What is central retinal artery occlusion (CRAO)?
A condition caused by blockage of the central retinal artery, leading to retinal ischaemia and sudden vision loss.
What are the common symptoms of CRAO?
Sudden, painless, severe vision loss in one eye, often described as a “curtain” descending over vision.
What is the main cause of CRAO?
Embolism or thrombosis blocking the central retinal artery, often linked to atherosclerosis.
What are risk factors for CRAO?
Hypertension, diabetes, atrial fibrillation, carotid artery disease, smoking, and hypercoagulable states.
What is the pathophysiology of CRAO?
Retinal ischaemia occurs due to obstruction of arterial blood flow, leading to cell death in the retina.
What are the characteristic fundoscopic findings in CRAO?
Pale retina with a “cherry-red spot” at the macula and attenuation of retinal arteries.
What is the “cherry-red spot” in CRAO?
The macula appears red due to preserved choroidal circulation against the pale ischaemic retina.
What is the prevalence of CRAO?
CRAO is rare, affecting approximately 1 in 10,000 people annually.
What is the role of carotid Doppler ultrasound in CRAO?
To assess for carotid artery stenosis or plaques that may have caused an embolism.
What is the role of ECG in CRAO management?
To identify arrhythmias like atrial fibrillation, a common cause of embolism.
What are the differential diagnoses for CRAO?
Central retinal vein occlusion, retinal detachment, giant cell arteritis, and optic neuritis.
What is the immediate management of CRAO?
Ocular massage, reducing intraocular pressure with acetazolamide or timolol, and urgent referral to ophthalmology.
Why is CRAO considered an ophthalmic emergency?
Delayed treatment increases the risk of irreversible retinal damage and permanent vision loss.
What systemic conditions are associated with CRAO?
Atherosclerosis, atrial fibrillation, carotid artery disease, and giant cell arteritis.
What is the prognosis for vision recovery in CRAO?
Poor, with most patients experiencing permanent severe vision loss despite treatment.
What is the role of fluorescein angiography in CRAO?
It assesses retinal circulation and confirms arterial obstruction.
What are potential complications of untreated CRAO?
Neovascularisation, neovascular glaucoma, and permanent vision loss.
What is the role of thrombolysis in CRAO?
Thrombolysis is being explored but is not yet widely established as a standard treatment for CRAO.
What investigations are needed to identify the cause of CRAO?
Carotid Doppler, ECG, echocardiography, and blood tests for hypercoagulable disorders.
What is the significance of an afferent pupillary defect (APD) in CRAO?
It indicates retinal ischaemia or optic nerve dysfunction in the affected eye.
What lifestyle modifications can help prevent CRAO?
Controlling blood pressure, managing diabetes, smoking cessation, and maintaining a healthy weight.
What is amaurosis fugax, and how is it related to CRAO?
Transient monocular vision loss due to temporary retinal ischaemia; it can precede CRAO.
What systemic conditions should be ruled out in CRAO patients?
Giant cell arteritis and cardiovascular embolic sources.
How does CRAO differ from central retinal vein occlusion (CRVO)?
CRAO presents with pale retina and cherry-red spot, while CRVO shows retinal haemorrhages and “blood and thunder” appearance.
