Central Retinal Artery Occlusion

Question 1

What is central retinal artery occlusion (CRAO)?

Answer 1

A condition caused by blockage of the central retinal artery, leading to retinal ischaemia and sudden vision loss.

Question 2

What are the common symptoms of CRAO?

Answer 2

Sudden, painless, severe vision loss in one eye, often described as a “curtain” descending over vision.

Question 3

What is the main cause of CRAO?

Answer 3

Embolism or thrombosis blocking the central retinal artery, often linked to atherosclerosis.

Question 4

What are risk factors for CRAO?

Answer 4

Hypertension, diabetes, atrial fibrillation, carotid artery disease, smoking, and hypercoagulable states.

Question 5

What is the pathophysiology of CRAO?

Answer 5

Retinal ischaemia occurs due to obstruction of arterial blood flow, leading to cell death in the retina.

Question 6

What are the characteristic fundoscopic findings in CRAO?

Answer 6

Pale retina with a “cherry-red spot” at the macula and attenuation of retinal arteries.

Question 7

What is the “cherry-red spot” in CRAO?

Answer 7

The macula appears red due to preserved choroidal circulation against the pale ischaemic retina.

Question 8

What is the prevalence of CRAO?

Answer 8

CRAO is rare, affecting approximately 1 in 10,000 people annually.

Question 9

What is the role of carotid Doppler ultrasound in CRAO?

Answer 9

To assess for carotid artery stenosis or plaques that may have caused an embolism.

Question 10

What is the role of ECG in CRAO management?

Answer 10

To identify arrhythmias like atrial fibrillation, a common cause of embolism.

Question 11

What are the differential diagnoses for CRAO?

Answer 11

Central retinal vein occlusion, retinal detachment, giant cell arteritis, and optic neuritis.

Question 12

What is the immediate management of CRAO?

Answer 12

Ocular massage, reducing intraocular pressure with acetazolamide or timolol, and urgent referral to ophthalmology.

Question 13

Why is CRAO considered an ophthalmic emergency?

Answer 13

Delayed treatment increases the risk of irreversible retinal damage and permanent vision loss.

Question 14

What systemic conditions are associated with CRAO?

Answer 14

Atherosclerosis, atrial fibrillation, carotid artery disease, and giant cell arteritis.

Question 15

What is the prognosis for vision recovery in CRAO?

Answer 15

Poor, with most patients experiencing permanent severe vision loss despite treatment.

Question 16

What is the role of fluorescein angiography in CRAO?

Answer 16

It assesses retinal circulation and confirms arterial obstruction.

Question 17

What are potential complications of untreated CRAO?

Answer 17

Neovascularisation, neovascular glaucoma, and permanent vision loss.

Question 18

What is the role of thrombolysis in CRAO?

Answer 18

Thrombolysis is being explored but is not yet widely established as a standard treatment for CRAO.

Question 19

What investigations are needed to identify the cause of CRAO?

Answer 19

Carotid Doppler, ECG, echocardiography, and blood tests for hypercoagulable disorders.

Question 20

What is the significance of an afferent pupillary defect (APD) in CRAO?

Answer 20

It indicates retinal ischaemia or optic nerve dysfunction in the affected eye.

Question 21

What lifestyle modifications can help prevent CRAO?

Answer 21

Controlling blood pressure, managing diabetes, smoking cessation, and maintaining a healthy weight.

Question 22

What is amaurosis fugax, and how is it related to CRAO?

Answer 22

Transient monocular vision loss due to temporary retinal ischaemia; it can precede CRAO.

Question 23

What systemic conditions should be ruled out in CRAO patients?

Answer 23

Giant cell arteritis and cardiovascular embolic sources.

Question 24

How does CRAO differ from central retinal vein occlusion (CRVO)?

Answer 24

CRAO presents with pale retina and cherry-red spot, while CRVO shows retinal haemorrhages and “blood and thunder” appearance.

Question 25

What is the role of ophthalmology referral in CRAO?

Answer 25

To confirm the diagnosis, initiate urgent management, and address complications like neovascularisation.