Safe, simple eye test may help save lives by preventing stroke

June 7, 2012

A simple eye test may someday offer an effective way to identify patients who are at high risk for stroke, say researchers at the University of Zurich. They showed that a test called ocular pulse amplitude (OPA) can reliably detect carotid artery stenosis (CAS), a condition that clogs or blocks the arteries that feed the front part of the brain. It's a known risk factor for stroke. The OPA test could be performed by ophthalmologists – physicians who treat eye diseases – during routine exams. The study, which is published in the June issue of Ophthalmology, the journal of the American Academy of Ophthalmology, confirmed that patients who had the lowest OPA scores also had the most seriously blocked arteries.

Each year, approximately 795,000 Americans suffer a new or recurrent , and more than 137,000 of these people die as a result. People with severe CAS are much more likely to suffer stroke. Physicians would like to catch and treat CAS before that can happen, but because CAS has no symptoms and an efficient test is not currently available, the disease often goes undetected.

The Swiss research team used a device called the dynamic contour tonometer to check the OPA of 67 patients who were assumed to have CAS. The OPA score is calculated by finding the difference between the two pressure levels that occur inside the eye during the two phases of the heartbeat − the systolic and diastolic. The tonometer measures the two pressure levels, then instantly computes the patient's OPA score. When blood flow to the eye is blocked by CAS, there is not much difference between the two pressure levels, so the OPA score is low. The study confirmed that patients with the lowest OPA scores also had the most seriously blocked arteries. The researchers used ultrasound exams to corroborate that each study participant had CAS and to detail the severity of his or her blockage.

"Our results show that ocular pulse is a reliable, safe screening test for carotid artery ," said lead researcher Pascal Bruno Knecht, M.D. "We recommend further study to confirm the value of using OPA to detect and assess the severity of CAS and to define its use in stroke prevention."

A research review performed for the U.S Preventive Services Task Force indicated that if an efficient screening test for CAS were available, the incidence of stroke and fatalities due to stroke could be substantially reduced. The review stated that the test should be able to detect clinically significant CAS, defined as 60 percent to 99 percent blockage of the carotid . Some high-tech tests, such as magnetic resonance angiography and color duplex ultrasound, already meet this standard, but they are expensive and not widely available. Their primary use is in diagnosing patients who already have symptoms of stroke.

It could be efficient to perform the OPA test during a standard eye exam, if the ophthalmologist is already using the dynamic contour tonometer to screen for glaucoma. This type of tonometer is not widely used in the United States, although it is in Europe.

The researchers say that other than CAS, very few diseases could cause low OPA scores, and that an ophthalmologist could easily rule out these other diseases during an eye exam.

Explore further: Researchers study outcomes of carotid artery stenting following prior carotid procedure

Related Stories

Researchers study outcomes of carotid artery stenting following prior carotid procedure

November 14, 2011
A new study shows that carotid artery stenting (CAS) following prior same-side carotid artery revascularization is safe, effective and results in lower incidences of in-hospital death, stroke and heart attack compared to ...

Impact of timing on carotid artery stenting after stroke or transient ischemic attack

November 14, 2011
A recent study found no significant difference in the outcome for patients who received carotid artery stenting (CAS) at more than 30 days post-transient ischemic attack (TIA) or stroke versus those who received CAS at 30 ...

Coronary artery spasms rare during dobutamine stress echo

March 9, 2012
(HealthDay) -- The occurrence of coronary artery spasm (CAS) during dobutamine stress echocardiography (DSE) is rare, with a prevalence of 0.4 percent, according to a study published in the March 15 issue of The American ...

Carotid artery stenting found to be safe in the elderly

March 26, 2012
Researchers at Thomas Jefferson University Hospital in Philadelphia and a multicenter team of investigators have found that carotid artery stenting (CAS) is safe and effective in patients age 70 and older.

Recommended for you

Research reveals biological mechanism of a leading cause of childhood blindness

November 16, 2017
Scientists at the Virginia Tech Carilion Research Institute (VTCRI) have revealed the pathology of cells and structures stricken by optic nerve hypoplasia, a leading cause of childhood blindness in developed nations.

Genetic treatment for blindness may soon be reality

November 11, 2017
Patients who had lost their sight to an inherited retinal disease could see well enough to navigate a maze after being treated with a new gene therapy, according to research presented today at AAO 2017, the 121st Annual Meeting ...

Study finds donor corneas can be safely preserved for longer period

November 10, 2017
Results from a large, national clinical trial show that corneal donor tissue can be safely stored for 11 days without negatively impacting the success of transplantation surgery to restore vision in people with diseases of ...

Exploring the genetics of glaucoma and retinal development

November 10, 2017
Guillermo Oliver, PhD, the Thomas D. Spies Professor of Lymphatic Metabolism, recently published two studies related to the eye, one on retinal formation and the other on the genetics behind glaucoma.

Scientists discover potential treatment to stop glaucoma in its tracks

November 6, 2017
Vision scientists at the University of California, Berkeley, and the University of Toronto have discovered that naturally occurring molecules known as lipid mediators have the potential to halt the progression of glaucoma, ...

New focus on correcting refractive vision

October 25, 2017
While doctors take delight in solving the common issue of refractive vision error by prescribing eye glasses, Flinders University researchers have found that many patients are upset with this solution and claim it affects ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.