An eye exam can help identify people with stroke
Last reviewed: 23.04.2024
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A simple eye test can be an effective way to identify patients who are at high risk of stroke, according to scientists from the University of Zurich (Switzerland).
Researchers have shown that a test called the "amplitude of the eye pulse" (AGI) can successfully recognize the narrowing of the carotid artery (CCA) - a condition in which the arteries that feed the frontal part of the brain occlude. This is a known risk factor for stroke. AGI can be performed by ophthalmologists during a routine examination.
Every year, almost 795,000 Americans are subjected to a first or recurrent stroke, more than 137,000 as a result of dying. Victims of a terrible disease are often people with severe narrowing of the carotid artery. Doctors would like to diagnose and treat this disorder before its onset, however, CCA does not have symptoms, and therefore often remains undetected.
Swiss scientists used a dynamic contour tonometer to check the amplitude of the eye pulse in 67 patients who presumably had SSA. The AGI was calculated by detecting the difference between the two levels of pressure inside the eye during the two phases of the heartbeat - systolic and diastolic. When the blood flow in the eye is blocked due to narrowing of the artery, the difference between the two pressure levels is small, so that the AGI is obtained low. The study confirmed that patients with the lowest AHI indices also have the most obstructed carotid arteries. To test the arteries, the subject was examined by ultrasound.
It is possible to detect arterial narrowing by means of more high-tech tests, such as magnetic resonance angiography and color duplex ultrasound scanning, but they are expensive and not available everywhere. First of all, they are used to diagnose PAS in patients who already have stroke symptoms. As for the AGI, it can be performed with a standard vision test, if the ophthalmologist already uses a dynamic contour tonometer to screen for glaucoma.
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