Amaurosis fugax: a clinical comparison.

Amaurosis fugax (transient monocular blindness) is a symptom of retinal ischemia just as contralateral hemiparesis and sensory loss are symptoms of cerebral ischemia. These symptoms are produced by atherosclerotic stenosis of the carotid vessels at the ipsilateral carotid bifurcation and emboli from these areas causing focal, repetitive, retinal ischemia. A study of 31 endarterectomy patients was undertaken to see if eight patients with amaurosis fugax (25%) could be differentiated from 22 patients with transient cerebral ischemia. The patients with amaurosis fugax were found to be younger. They all had 75% or greater stenosis of the internal carotid artery at the bifurcation on the symptomatic side. They all had unilateral visual symptoms and these symptoms were relieved by surgery. The patients with amaurosis fugax were devoid of cardiac disease, while 45% of the cerebral ischemic patients had documented myocardial disease. Amaurosis fugax (transient monocular blindness) in the setting of clinically significant atheroslerosis of the carotid vessels is an indication for carotid endarterectomy.