Retinal Artery Occlusion
Overview
Plain-Language Overview
Retinal Artery Occlusion is a sudden blockage of the blood flow in one of the arteries supplying the eye's retina, which is the light-sensitive tissue at the back of the eye. This condition primarily affects the visual system and can cause a rapid and painless loss of vision in one eye. The retina needs a constant supply of oxygen and nutrients delivered by these arteries to function properly. When the artery is blocked, the retina can become damaged due to lack of blood flow, leading to permanent vision loss if not treated promptly. Common causes include embolism or thrombosis, often related to cardiovascular disease. It is considered an eye emergency because the longer the retina is deprived of blood, the worse the damage. Early recognition and diagnosis are critical to preserving vision.
Clinical Definition
Retinal Artery Occlusion (RAO) is an acute ischemic event characterized by obstruction of the central retinal artery or one of its branches, leading to sudden, painless monocular vision loss. The core pathology involves arterial embolism or thrombosis causing cessation of blood flow to the inner retinal layers, resulting in ischemic infarction. The most common embolic sources include carotid artery atherosclerosis and cardiac emboli such as from atrial fibrillation. RAO is a form of ocular stroke and is a major cause of permanent visual impairment. Fundoscopic examination typically reveals a pale retina with a cherry-red spot at the fovea due to preserved choroidal circulation. The condition requires urgent evaluation to identify underlying systemic vascular risk factors and prevent further ischemic events.