Central Retinal Vein Occlusion (CRVO)

Question 1

what is this associated with?

Answer 1

Virchow’s triad- thrombus development

Question 2

virchow’s triad

Answer 2

1. endothelial damage (diabetes)
2. abnormal blood flow (hypertension)
3. hypercoagulable state (cancer)

Question 3

describe how thrombus development causes CRVO

Answer 3

• the artery sits on top of the vein
• artery becomes stiff from atheroma and thrombus development
• presses on the pliable vein causing it to be blocked
• increased back pressure can cause haemorrhage

Question 4

which is more common - CRVO or CRAO?

Answer 4

CRVO

Question 5

presentation of CRVO

Answer 5

sudden painless loss of vision

rubeotic eye

Question 6

presentation of CRVO on fundoscopy

Answer 6

retinal haemorrhages
dilated torturous vessels
disc and macula swelling
unable to make out edges of disc
cotton wool spots (infarcts in nerve fibre layer)
dark retina

Question 7

define branch retinal vein occlusion (BRVO)

Answer 7

occlusion of a tributary of the central retinal vein

Question 8

what causes BRVO

Answer 8

macula oedema/ fluid-filled spaces on the retina can press on the vein

Question 9

presentation of BRVO

Answer 9

• can be asymptomatic
• painless disturbance in vision
• loss of part of field