Assess Stroke Risk Through Eye!

High blood pressure, also known as hypertension, is not only a risk factor for heart disease but also the single most significant risk factor for stroke. Stroke occurs when blood flow stops flowing to the brain, either because of a clot or a hemorrhage.

Stroke is number 4 killer and a leading cause of disability in the United States. It is, however, merely impossible for doctors to predict which hypertensive patients are most likely to develop a stroke. Now, a simple eye examination might just provide that information.

A study revealed that retinal imaging, a non-invasive and cheap way of examining the blood vessels of the retina, might someday help assess whether a person is more likely to develop a stroke. Researchers from the National University of Singapore reported on August 12, 2013 in the American Heart Association journal ‘Hypertension’ that the retina provides information on the status of blood vessels in the brain.

For an average 13 years, researchers tracked occurrence of stroke in 2,907 patients with hypertension but had not experienced a stroke previously. Photographs of the retina of each participant were taken at baseline. Retina is the light-sensitive layer of cells at the back of the eyeball.

When high blood pressure damages blood vessels in the retina, a condition called hypertensive retinopathy occurs. On photographs, it will be scored as none, mild or moderate/severe.

146 participants experienced a stroke caused by a blood clot and 15 by bleeding in the brain (hemorrhage) during the follow-up period.

After adjusting for several stroke risk factors like age, sex, race, cholesterol levels, blood sugar, body mass index, smoking and blood pressure readings, the researchers found that the risk of stroke was 35 percent higher in those with mild hypertensive retinopathy and 137 percent higher in those with moderate or severe hypertensive retinopathy.

Even for patients who were on medication and achieving good blood pressure control, the risk of a blood clot was 96 percent higher in those with mild hypertensive retinopathy and 198 percent higher in those with moderate or severe hypertensive retinopathy. 

While the findings did add to previous research on the value of retinopathy as an indicator of small vessel disease and increased risk of stroke, the researchers felt that it is too early to recommend changes in clinical practice. Further studies are required to confirm their findings and examine if retinal imaging could be useful in offering additional information about stroke risk in people with high blood pressure.