Central Retinal Artery Occlusion
Central Retinal Artery Occlusion (CRAO) is the blockage of flow through the central retinal artery, which is a branch of the ophthalmic artery. Its main risk factor is Atherosclerosis. The most common cause is an embolus from carotids/heart, but it can also be caused by GCA. If its symptoms are transient in duration, it's known as Retinal TIA = Amaurosis Fugax.
Presentation
Sudden painless loss of vision – Like a curtain/shutter across vision over seconds
O/E:
Pale retina
Cherry-red spot – The macula is supplied by the cilioertinal artery which is usually not affected in CRAO. This leaves the macula to show the red-coloured choroid below.
RAPD – No constriction in affected eye, Constriction in normal eye
Investigations and Management
Important to rule out GCA with an ESR and Temporal artery biopsy.
If the patient presents shortly after symptoms develop, the thrombus can be dislodged by an ocular massage, and medications to reduce the intraocular pressure.

