Dr S.S. Gill
Ipoh Echo’s EYE HEALTH series continues with Consultant Eye Surgeon Dr S.S. GILL talking to us about transient visual disturbance.
Amaurosis Fugax (AF) is derived from the greek language. “Amaurosis” means “to obscure or darken” and “fugax” means “fleeting”. Hence, the term Amaurosis Fugax essentially describes a brief or transient loss of vision in one or both eyes that may last from a few seconds to minutes. It is sometimes referred to as “Transient Monocular Visual Loss” if it affects one eye or “Transient Binocular Visual Loss” if it affects both eyes. Fortunately, in most cases the visual loss occurs in one eye.
WHAT IS SO IMPORTANT ABOUT AMAUROSIS FUGAX?
Such episodic or transient visual disturbance or loss may be a warning of a serious underlying condition such as an impending stroke or a decrease in blood circulation to the brain or eyes. In most cases, by the time a patient with such episodic visual loss presents to the doctor, the symptoms may have resolved but this does not mean that it can be taken lightly as it will need a thorough investigation to look for sinister causes of such transient visual loss.
SOME CAUSES OF AMAUROSIS FUGAX
Carotid Artery narrowing: The carotid artery on either side of the neck supplies blood from the heart to the brain and eyes through small branches. These blood vessels can get stenosed (narrowed) due to plaques in the walls of the vessels. Should these plaques break off, it may prevent the blood from reaching the eyes. Several causes of vessel narrowing include hypercholesterolemia (increased cholesterol levels), diabetes mellitus, hypertension and smoking.
- Clots from the heart valves or walls of the heart can get dislodged and block the vessels of the eye.
- Certain blood diseases like sickle cell disease and anaemia.
- Acute angle closure glaucoma is also one of the causes of such sudden loss of the vision.
INVESTIGATIONS THAT MAY BE DONE
Should the clinician consider your condition to point towards Amaurosis Fugax, then it would not be surprising if you are sent for a battery of investigations. The checks and investigations include a dilated retinal examination, ultrasound doppler examination of your carotid arteries, an MRI or CT Scan of the brain to look for a stroke, a thorough cardiovascular examination, a blood test to check for diabetes mellitus and hypercholesterolemia.
Once the clinician determines the cause of Amaurosis Fugax, then the appropriate treatment will be administered. Blood thinning anti-platelet medication like aspirin may be given in order to reduce clotting. Systemic conditions like diabetes mellitus and hypertension will need to be rapidly stabilized. If there is a blockage of the carotid artery, then surgery of the artery (carotid endarterectomy) will need to be performed.
SOME TAKE HOME POINTS
Get a prompt eye examination should you be having symptoms of transient blurred vision. If you are diabetic or hypertensive, then take your medication without fail and make sure it is well controlled. Avoid smoking as this increases risk of serious problems many fold.