Strokes can occur suddenly and without warning. The effects can be devastating, either resulting in a permanent disability or worse, death.  In the United States alone, more than 700,000 people suffer from a stroke every year.

While no one can be sure whether they will have a stroke, risk factors such as high blood pressure or heart disease are often used to predict whether someone has a higher risk. However, according to some studies, the eyes may provide vital information as to whether someone is likely to have a stroke.



The results of a study published in Neurology October 11, 2005, suggest that tiny blood vessels in the retina undergo small changes before someone suffers from a stroke. The study undertaken at the University of Sydney, Australia, involved photographing the retinas of 3,654 patients aged 49 or above. Those without diabetes and retinal arteriolar signs were assessed for the presence of retinopathy (non-inflammatory damage).

Over the period of seven years, it was found that those who suffered with retinopathy had a 70 percent greater chance of suffering from stroke. This percentage took into account the typical risk factors associated with stroke including age, sex, blood pressure and whether or not they smoked. It was noted that the retinopathy was stronger in those without diabetes or severe hypertension.

The results from this study could enable doctors to monitor a patient's eyes for stroke risk, despite the absence of other risk factors such as hypertension. By doing this it could be possible to prevent many more strokes than is possible using conventional methods and ultimately save more lives.

Interestingly, the eyes may provide another link to the risks of someone suffering from a stroke. According to a study published in the American Academy of Neurology, it was found that the shingles virus may be a key indicator of stroke risk. Of particular note was the fact that those who contracted ocular shingles (where skin in and around the eye and becomes infected), had a four times greater risk of suffering from a stroke in the year after suffering from shingles. As with the previous study on the presence of retinopathy, the participants of this study also displayed no other risk factors associated with stroke.

It's not all bad news though. Although those who suffered from ocular shingles were more likely to have an ischemic stroke (interruption of blood flow causing brain cells to die), they were less likely to have hemorrhagic stroke (burst blood vessel causing bleeding around the brain). While these findings don’t prove that ophthalmic shingles will cause a stroke, it does provide useful evidence that someone may be more at risk of an ischemic stroke if they’ve had ocular shingles.

Stroke is one of the leading causes of death along with heart disease and cancer. Although as yet, there is no cure for stroke, it is possible to predict the likelihood of their occurrence by looking for warning signs such as hypertension. However, not everyone who suffers a stroke has these symptoms. Therefore, research linking the eye to the possibility of a stroke, despite the absence of other symptoms, makes it particularly valuable for predicting strokes in those who would otherwise have been unaware they were at risk.