21/03/2026
Central Retinal Artery Occlusion (CRAO)
Central Retinal Artery Occlusion (CRAO): a true ophthalmic emergency where sudden interruption of retinal blood supply leads to rapid, often irreversible vision loss.
Central retinal artery occlusion occurs due to an embolus or thrombus most commonly originating from the internal carotid or cardiac circulation lodging within the central retinal artery. As this artery is the sole supply to the inner retinal layers, its occlusion results in acute ischemia, presenting clinically as sudden, painless, profound monocular vision loss. On fundus examination, the retina appears pale and edematous, with a classic cherry-red spot at the macula due to preserved choroidal circulation. Early recognition is critical, as retinal survival time is extremely limited.
This diagram depicts the arterial supply of the eye, beginning from the internal carotid artery, which gives rise to the ophthalmic artery. The ophthalmic artery further branches into the central retinal artery that enters the eye through the optic nerve to supply the inner retinal layers.
The image highlights the site where an embolus or thrombus becomes lodged within the central retinal artery, obstructing blood flow. As a result, the inner layers of the retina undergo acute ischemia due to loss of oxygen and nutrient supply.
It also demonstrates adjacent branches such as the supraorbital artery, helping to understand the overall orbital vascular anatomy.