A B C D E F G H I J K L M N O P R S T U V W

RETINAL ARTERY OCCLUSION

What is Retinal Artery Occlusion ?

The retina is supplied with blood by a single artery (the ophthalmic artery) which runs alongside and within the optic nerve. This artery also provides blood separately to the optic nerve itself. The blood in the eye is drained from the retina by a central vein. Within the retina the artery and veins have separating branches to serve different parts of the retina. Interruption of the blood supply of either system results in varying degrees of visual loss. Blockage of the artery results in abrupt visual disturbance.

How does Retinal Artery Occlusion occur ?

Arterial occlusion may result from closure of the vessel due to atheroma (hardening of the artery). It can also result from embolism when a small fragment of cholesterol or blood platelets break off and lodge within the narrow arteries within the eye. If they pass through then this is the condition resulting in amaurosis fugax. However if they are lodged permanently then complete loss of vision occurs. Inflammation of the arterial wall may also result in obstruction. The most important cause is a generalised inflammatory condition called Temporal Arteritis (giant cell arteritis). This needs urgent treatment to prevent both eyes becoming affected with resultant complete loss of vision. Arterial occlusion occurs more commonly with people with diabetes, high blood pressure and heart disease.. Smoking cigarettes increases this risk.

Treatment Involved for Retinal Artery Occlusion

Arterial occlusion may result in sudden and devastating loss of vision. General examination is important to test for high blood pressure and for the condition of temporal arteritis. This involves taking a simple blood sample. The carotid arteries will also need to be examined as these are the most likely source of any embolism. This is usually undertaken by using a doppler system to study the flow within the carotid arteries to establish if there is significant narrowing. If narrowing is established and the individual is considered fit enough, then an operation called endarterectomy may be undertaken. This reduces the risk of the individual developing a stroke in the future. There is unfortunately no effective treatment for arterial occlusion however if the patient is seen within 2 hours of the event it is sometime possible to restore the circulation by massaging the eyeball or by suddenly reducing the eye pressure. Low dose aspirin is usually advised if there are no contraindications. This helps to prevent a further episode of vascular occlusion in the eye. The condition of temporal arteritis requires treatment with steroids initially with high dosage. Long term treatment and monitoring are necessary.

During Treatment for Retinal Artery Occlusion

It is important to control high blood pressure and to discontinue smoking. Steroid treatment must not be discontinued until advised.

After Treatment for Retinal Artery Occlusion

Temporal arteritis requires treatment with cortisone tablets and this must be carefully monitored with regular blood tests. If the condition recurs then there is a risk to vision from the other eye due to ischaemic optic neuropathy.

If Retinal Artery Occlusion is Left Untreated

The most important consideration is to detect and treat any underlying condition which may have serious health implications and in the case of temporal arteritis loss of vision in the fellow eye.