Amaurosis Fugax

Temporary monocular blindness from retinal TIA

Overview

Amaurosis fugax, a term meaning fleeting darkness, is a temporary painless loss of vision in one eye, typically lasting seconds to minutes and sometimes described as a curtain or shade descending over the vision before full recovery. It is most commonly caused by a temporary interruption of blood flow to the retina, often from a small embolus of cholesterol, platelets, or fibrin traveling from an atherosclerotic carotid artery or from the heart, and in that setting it is considered a form of transient ischemic attack. Other causes include giant cell arteritis, particularly in older adults, vasospasm, and blood clotting disorders. Because it can be a warning sign of stroke or of permanent retinal artery occlusion, it is evaluated urgently, typically with imaging of the carotid arteries and cardiac assessment. Retinal emboli, such as bright cholesterol fragments known as Hollenhorst plaques, may sometimes be seen at the branching points of retinal arteries.