CRAO

Question 1

What is CRAO?

Answer 1

Central Retinal Artery Occlusion (CRAO) is the blockage of the central retinal artery, leading to sudden, painless vision loss.

Question 2

What are the common causes of CRAO?

Answer 2

• Age
• Smoking
• Diabetes
• High blood pressure (HBP)
• Hyperlipidemia
• Cardiac valve or carotid artery disease
• Sickle cell disease
• Leukemia

Question 3

What are the key signs of CRAO?

Answer 3

• Reduced visual acuity (VA)
• Relative afferent pupillary defect (RAPD)
• Pale and oedematous retina
• Cherry red spot
• Emboli in arteries
• White fluffy vessels
• Attenuated narrow artery
• Cattle trucking sign (segmented blood flow)

Question 4

What is a classic symptom of CRAO?

Answer 4

Sudden painless loss of vision (amaurosis fugax).

Question 5

What does the ‘cherry red spot’ indicate in CRAO?

Answer 5

It is a hallmark sign caused by the contrasting appearance of the fovea against the pale, oedematous retina.

Question 6

Why is an emergency referral needed for CRAO?

Answer 6

It is a sight-threatening condition that requires immediate attention at a hospital eye service (HES).

Question 7

How can breathing into a paper bag help in CRAO?

Answer 7

It elevates CO2 levels in the blood, causing vasodilation, which may improve oxygen flow to the eye.

Question 8

What is the purpose of ocular massage in CRAO?

Answer 8

To fluctuate pressure in the eye and potentially dislodge the embolism causing the occlusion.

Question 9

What is the role of acetazolamide in CRAO management?

Answer 9

Acetazolamide is used to reduce intraocular pressure (IOP) and improve blood flow.

Question 10

What surgical procedure can help remove a clot in CRAO?

Answer 10

Pars plana vitrectomy may be performed to surgically remove the clot.

Question 11

How does hyperbaric oxygen therapy help in CRAO?

Answer 11

It increases oxygen delivery to the ischemic retinal tissue, potentially improving the outcome.

Question 12

What is the ‘cattle trucking sign’ in CRAO?

Answer 12

It refers to the segmented or interrupted blood flow seen in retinal arteries due to the occlusion.

Question 13

What are the potential risk factors for CRAO?

Answer 13

• Hyperlipidemia
• Hypertension
• Diabetes
• Smoking
• Carotid artery disease

Question 14

How does sickle cell disease contribute to CRAO?

Answer 14

Abnormal red blood cells can block retinal arteries, leading to occlusion.

Question 15

What systemic diseases are associated with CRAO?

Answer 15

• Cardiac valve disease
• Carotid artery disease
• Leukemia

Question 16

What is the RAPD sign in CRAO?

Answer 16

Relative afferent pupillary defect (RAPD) is when the pupil reacts less to light on the affected side, indicating optic nerve involvement.

Question 17

Why might emboli be found in arteries in CRAO?

Answer 17

Emboli, such as cholesterol plaques, may travel from the heart or carotid arteries and block retinal arteries.

Question 18

What can be done immediately to attempt to restore blood flow in CRAO?

Answer 18

• Ocular massage
• Breathing into a paper bag
• Referral to HES for further treatment

Question 19

Why is timely intervention crucial in CRAO?

Answer 19

The retina is highly sensitive to oxygen deprivation, and irreversible vision loss can occur without prompt treatment.

Question 20

What should an optometrist do if they suspect CRAO?

Answer 20

Urgently refer the patient to a hospital eye service (HES) for immediate management.