Stroke and Eye Findings

Transient Monocular Visual Loss

Although transient monocular visual loss may result from retinal transient ischemic attack (TIA), it is important to emphasize that there are numerous nonvascular causes of transient monocular visual loss, which require an emergent detailed ocular examination; therefore, an ophthalmic consultation should be obtained before obtaining an extensive workup for presumed vascular transient monocular visual loss (so-called “amaurosis fugax”). Retinal TIAs classically present as sudden, complete blackout of vision in one eye, lasting few minutes without residual visual loss. Ocular examination may show retinal emboli or may be normal. The workup is similar to that of a cerebral TIA, including stroke protocol brain imaging, since about 25% of patients with acute retinal ischemia have concomitant acute cerebral ischemia . Multiple episodes of transient visual loss or painful transient visual loss in the elderly should raise the possibility of giant cell arteritis .

Permanent Monocular Visual Loss

Partial or complete monocular loss of vision may occur in patients with ipsilateral carotid artery disease, or emboli in the anterior circulation. This results most often from a central retinal artery occlusion (CRAO) ( Fig. 88.1 ) or from one or multiple branch retinal artery occlusions (BRAOs) ( Fig. 88.2 ). In such cases, emboli may be seen in the affected vessels. The most common emboli that occlude retinal arterioles are made of cholesterol, fibrin platelets, and calcium fragments ( Table 88.1 ). Acute retinal ischemia should be evaluated emergently, in a similar manner as with acute cerebral infarctions .

Venous stasis retinopathy and ocular ischemic syndrome are caused by severe carotid obstructive disease and poor collateral circulation. The retinopathy is characterized by insidious onset, dilated and tortuous retinal veins, peripheral microaneurysms, and dot-blot hemorrhages in the mid-peripheral retina, associated with neovascularization when ocular ischemic syndrome develops ( Fig. 88.3 ). Patients with this condition develop progressive and often irreversible visual loss, sometimes associated with cerebral hypoperfusion, and the prognosis is poor .

Ischemic optic neuropathy, anterior or posterior, results from small vessel disease and is usually not associated with large artery disease, explaining why carotid artery evaluation is not usually indicated in patients with classic anterior ischemic optic neuropathy .

Permanent Binocular Visual Loss

Partial or complete contralateral homonymous hemianopic visual field defects may result from cerebral ischemia in the anterior circulation. This is most often caused by occlusion of branches of the middle cerebral artery, but it may result from occlusion of the anterior choroidal artery or some of its branches to the optic tract and lateral geniculate body .

Horner Syndrome

Horner syndrome is a classic sign of carotid dissection and may also occur in patients with atherosclerotic carotid artery disease. The Horner syndrome may be isolated (often with ipsilateral facial pain) or may be associated with other neurological symptoms and signs of carotid artery disease .

Referred Pain

Isolated facial pain (often periocular) may be a symptom of carotid occlusive disease, even without other symptoms and signs of vascular disease. It is usually a referred pain resulting from ischemia or compression of the trigeminal branches. It may also be part of the ocular ischemic syndrome .

Ocular Motor Nerve Paresis

Exceptionally, patients with acute occlusion or severe ICA stenosis may develop one or more ocular motor nerve pareses on the side of the occlusion, either in isolation or with signs of ocular ischemia .