Central retinal artery occlusion

Question 1

What is central retinal artery occlusion

Answer 1

occurs where something blocks the flow of blood through the central retinal artery. The central retinal artery supplies the blood to the retina. It is a branch of the ophthalmic artery, which is a branch of the internal carotid artery.

Question 2

Most common cause of central retinal artery occlusion

Answer 2

atherosclerosis. It can also be caused by giant cell arteritis, where vasculitis affecting the ophthalmic or central retinal artery causes reduced blood flow.

Question 3

Risk factors for central retinal artery occlusion

Answer 3

Older age
Family history
Smoking
Alcohol consumption
Hypertension
Diabetes
Poor diet
Inactivity
Obesity
Polymyalgia rheumatica

Question 4

Presentation of central retinal artery occlusion

Answer 4

Blockage of the central retinal artery causes sudden painless loss of vision.

There will be a relative afferent pupillary defect. This is where the pupil in the affected eye constricts more when light is shone in the other eye compared when it is shone in the affected eye. This occurs because the input is not being sensed by the ischaemic retina when testing the direct light reflex but is being sensed by the normal retina during the consensual light reflex.

Fundoscopy will show a pale retina with a cherry-red spot. The retina is pale due to a lack of perfusion with blood. The cherry-red spot is the macula, which has a thinner surface that shows the red coloured choroid below and contrasts with the pale retina.

Question 5

Management of central retinal artery occlusion

Answer 5

Patients with suspected central retinal artery occlusion should be referred immediately to an ophthalmologist for assessment and management.

Giant cell arteritis is an important potentially reversible cause. Therefore older patients are tested and treated for this if suspected. Testing involves an ESR and temporal artery biopsy and treatment is with high dose steroids (i.e. prednisolone 60mg).