Central Retinal Artery Occlusion (CRAO)

Question 1

what does the central artery of the retina supply?

Answer 1

inner 2/3rds of the retina

Question 2

what supplies the peripheral 1/3rd of the retina?

Answer 2

choroid

Question 3

what artery supplies the optic nerve head and macula

Answer 3

posterior ciliary arteries

Question 4

presentation of CRAO

Answer 4

• sudden painless loss of vision

- RAPD

Question 5

presentation of CRAO on fundoscopy

Answer 5

cherry red spot at the macula (supplied by posterior ciliary arteries)
pale oedematous retina (retina opacifies in ischaemia)

Question 6

what is an RAPD

Answer 6

relative afferent pupil defect

the pupils respond differently to light due to unilateral disease of retina or optic nerve

Question 7

how do you check for a RAPD?

Answer 7

swinging light test

Question 8

cause of CRAO

Answer 8

form of stroke
carotid artery disease
embolus from heart

Question 9

define amaurosis fugax

Answer 9

this is transient CRAO where the end artery is momentarily blocked

Question 10

presentation of amaurosis fugax

Answer 10

transient painless visual loss
curtain coming down <5 minutes
lasts around 5 minutes with a full recovery

Question 11

management of amaurosis fugax

Answer 11

usually nothing abnormal on examination

refer to stroke clinic

Question 12

define branch retinal artery occlusion (BRAO)

Answer 12

this is blockage of one of the tributaries of the central artery of the retina

it therefore causes less damage