Forum for Science, Industry and Business

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

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 stroke, 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 amplitude is a reliable, safe screening test for carotid artery stenosis," 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 arteries. 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.

Note to media: Contact Media Relations to request full text of the study, arrange interviews with experts, and request images.

Mary Wade | EurekAlert!
Further information:
http://www.aao.org

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...