CRAO

Question 1

What is central retinal artery occlusion (CRAO)?

Answer 1

= occlusion of central retinal artery at level of lamina cribosa or just behind.

Question 2

What is the aetiology/cause of CRAO? (hint: 2)

Answer 2

1. Vaso-obliteration - atherosclerosis (thinning/hardening of arteries) at level of lamina cribosa
2. Carotid Embolism - Blood clot formed in arteries

Question 3

What are the two main symptoms of CRAO?

Answer 3

1. Sudden, Unilateral, Painless Loss of Vision

Question 4

What are the three signs of CRAO? And what are the End Stage signs?

Answer 4

1. Attenuation (reduction) of arteries and veins.
2. Extensive Retinal whitening/clouding.
3. Cherry Red spot at macula.
4. RAPD

End Stage Signs:

• Optic Nerve v. pale and thin.
• Atrophy of Optic Nerve and retinal layers.

Question 5

What is Branch Retinal Artery Occlusion (BRAO)?

Answer 5

= Occlusion of a branch of the central retinal artery.

Question 6

What is the aetiology/cause of BRAO?

Answer 6

Aetiology = Embolism (moving blood clot)

Question 7

What are the signs and symptoms of BRAO?

Answer 7

1. Sudden, Painless sectoral loss of vision
2. Altitudinal VF loss (depending on location)
3. Central vision can vary depending on macula involvement
4. Possible RAPD if hemispheric
5. END STAGE = Permanent VF defect.

Question 8

What is the Referral for CRAO and BRAO?

Answer 8

• If detected within 12-48hrs of onset = EMERGENCY TO A&E

- If detected over 48hrs = ROUTINE TO OPTHALMOLOGY & GP

Question 9

What is the aim of the management for CRAO and BRAO? and what are the different things to do?

Answer 9

Aim = to re-establish blood supply to retinal tissues within the 12-48hr period

Different actions:

1. Breathe in paper bag (CO2 is a vasodilator)
2. Lie Down (to reduce IOP)
3. Address hypertension since its a risk factor

Question 10

What are the treatment options for CRAO/BRAO?

Answer 10

Surgery:

• Thrombolysis (dissolves clots in vessels)
• Acetazolamide (decreases eye pressure)
• YAG laser (gets rid of clots)