A central retinal artery occlusion (CRAO) is characterised by sudden and severe loss of vision. Although usually caused by atherosclerosis-related thrombus in the optic nerve head, a CRAO may also be secondary to emboli eg calcific emboli from cardiac valves, cholesterol emboli originating from diseased carotid arteries, or importantly CRAO can be due to giant cell arteritis (GCA).
