Amaurosis Fugax

This is also referred to as a Retinal TIA, or a Transient CRAO. Here, there's a transient loss of vision due to hypoperfusion of the retina/optic nerve. Most commonly, this is due to an embolus from the carotid which transiently occludes the central retinal, branch retinal, or ophthalmic artery.

N.B. Think of CRAO as a “Stroke of the eye” as there’s a permanent occlusion of the central retinal artery (branch of the ophthalmic). Therefore, think of Amaurosis fugax as a “TIA if the eye”.

This is commonly confused with vision loss that occurs in GCA. Though GCA can cause vision loss, it's much more commonly due to an arteritis anterior ischaemic optic neuropathy (AAION). GCA can also cause a CRAO, but this is a lot less common (10%). This is why it’s important to rule out GCA in these patients as it completely shifts the management plan.

Investigations and Management

• Detailed history - Aim is to rule out GCA (e.g. headache, scalp tenderness, jaw claudication)

• Examination - Eye, temporal tenderness, cardiovascular, pulse, carotids

• Bloods - FBC, U&E, CRP, ESR

• Carotid ultrasound

• Urgent stroke work-up

N.B. Remember that, if GCA is suspected, then the patient needs to be started on high-dose steroid therapy (i.e. Oral Prednisolone 60mg or IV Methylprednisolone) to prevent permanent vision loss.