MONDAY, August 12, 2013 — A simple eye exam can shed light on cases of high blood pressure as a primary risk factor for stroke. “Our focus in this current study was to examine people who already have a high blood pressure,” said Kamran Ikram, MD, PhD, lead author of the study. Dr. Ikram is assistant professor in the Singapore Eye Research Institute at the National University of Singapore.
“Among all those persons who have high blood pressure," Dr. Ikram said, "it is still not possible to predict exactly who will develop a stroke," a condition in which a blood clot or bleeding in the brain can cause disability or death.
Ikram and other researchers followed 2,907 patients with high blood pressure — ages 50 to 73 years — for 13 years to see if there was a way to predict stroke among those with hypertension.
“As the back side of the eye — called the retina — gives an easily assessable way to examine damage to small blood vessels due to high blood pressure," Ikram said, "we tried to examine if such a simple eye examination may also give additional information on the development of stroke.” The eye’s retina has a layer of light-sensitive cells where, if there were differences among the high blood pressure patients, they would be clearly visible.
During the course of the long study, 146 of the patients had stroke from a blood clot in the brain, and 15 more had stroke from bleeding in the brain.
“In our study this eye exam was performed in a research setting,” added Ikram. “We showed in persons with high blood pressure that damage to the blood vessels in the retina, called hypertensive retinopathy, is linked to an increased risk of stroke,” he said. This difference in risk existed even if high blood pressure was under control with medication.
The eye exam at the optometrist has typically been used to visualize damage to the eye from optical causes, not to predict stroke. Photographing the retina of the eye — a test called assessment of hypertensive retinopathy — is something that can be done in a primary care clinic, in optical shops, or in a hospital.
Ikram cautioned that his results are preliminary. “At this stage it is too early to recommend changes in clinical practice. Other studies need to confirm our findings and show that retinal imaging provides additional information on predicting the risk of stroke in persons with high blood pressure," he said.
KEY TAKEAWAYS
- High blood pressure is the most important risk factor for stroke.
- Research shows a simple exam in which the back of the eye is photographed may be able to determine which hypertension patients are most at risk for stroke.
- Researchers say it is too early to change clinical practice, but in the future a photographic eye exam may help predict — and prevent — stroke.
By Jennifer J Brown, PhD, Everyday Health Staff Writer