Simple eye scan can reveal extent of Multiple Sclerosis

A simple eye test may offer a fast and easy way to monitor patients with multiple sclerosis (MS), medical experts say in the journal Neurology. Optical Coherence Tomography (OCT) is a scan that measures the thickness of the lining at the back of the eye - the retina. It takes a few minutes per eye and can be performed in a doctor’s surgery.

In a trial involving 164 people with MS, those with thinning of their retina had earlier and more active MS. The team of researchers from the Johns Hopkins University School of Medicine say larger trials with a long follow up are needed to judge how useful the test might be in everyday practice. The latest study tracked the patients’ disease progression over a two-year period.

Unpredictable disease

Multiple sclerosis is an illness that affects the nerves in the brain and spinal cord causing problems with muscle movement, balance and vision. In MS, the protective sheath or layer around nerves, called myelin, comes under attack which, in turn, leaves the nerves open to damage.

There are different types of MS - most people with the condition have the relapsing remitting type where the symptoms come and go over days, weeks or months. Usually after a decade or so, half of patients with this type of MS will develop secondary progressive disease where the symptoms get gradually worse and there are no or very few periods of remission.

Another type of MS is primary progressive disease where symptoms get worse from the outset. There is no cure but treatments can help slow disease progression. It can be difficult for doctors to monitor MS because it has a varied course and can be unpredictable.

Brain scans can reveal inflammation and scarring, but it is not clear how early these changes might occur in the disease and whether they accurately reflect ongoing damage.

Scientists have been looking for additional ways to track MS, and believe OCT may be a contender. OCT measures the thickness of nerve fibres housed in the retina at the back of the eye. Unlike nerve cells in the rest of the brain which are covered with protective myelin, the nerve cells in the retina are bare with no myelin coat. Experts suspect that this means the nerves here will show the earliest signs of MS damage.

The study at Johns Hopkins found that people with MS relapses had much faster thinning of their retina than people with MS who had no relapses. So too did those whose level of disability worsened. Similarly, people with MS who had inflammatory lesions that were visible on brain scans also had faster retinal thinning than those without visible brain lesions. Study author Dr Peter Calabresi said OCT may show how fast MS is progressing.

"As more therapies are developed to slow the progression of MS, testing retinal thinning in the eyes may be helpful in evaluating how effective those therapies are," he added.

In an accompanying editorial in the same medical journal that the research is published in, MS experts Drs Robert Bermel and Matilde Inglese say OCT “holds promise” as an MS test.

(Image courtesy: Boston University Eye Associates, Inc.)

Using the Eye as a ‘Window Into the Brain’

An inexpensive, five-minute eye scan can accurately assess the amount of brain damage in people with the debilitating autoimmune disorder multiple sclerosis (MS), and offer clues about how quickly the disease is progressing, according to results of two Johns Hopkins studies.

“The eye is the window into the brain and by measuring how healthy the eye is, we can determine how healthy the rest of the brain is,” says Peter A. Calabresi, M.D., a professor of neurology at the Johns Hopkins University School of Medicine, and leader of the studies described in recent issues of The Lancet Neurology and the Archives of Neurology. “Eye scans are not that expensive, are really safe, and are widely used in ophthalmology, and now that we have evidence of their predictive value in MS, we think they are ready for prime time. We should be using this new quantitative tool to learn more about disease progression, including nerve damage and brain atrophy.”

Calabresi and his colleagues used optical coherence tomography (OCT) to scan nerves deep in the back of the eye, applying special software they co-developed that is capable of assessing previously immeasurable layers of the light-sensitive retinal tissue. The scan uses no harmful radiation and is one-tenth the cost of an MRI. The software will soon be widely available commercially.

Hand-held 3D scanner could simplify medical imaging

Although there are various efforts under way to create a working Star Trek-like medical tricorder, such a device isn’t available for general use just yet. In the meantime, however, doctor’s offices may soon be equipped a piece of equipment that wouldn’t look at all out of place in the sick bay of the Enterprise. Developed by engineers from the University of Illinois at Urbana-Champaign, it’s a hand-held scanning device that provides real-time three-dimensional images of the insides of patients’ bodies.

The scanner utilizes optical coherence tomography (OCT), which has been described as “optical ultrasound,” in that it uses reflected light – as opposed to reflected sound – to image internal structures. Along with an OCT system, the device also incorporates a near-infrared light source, a video camera for obtaining images of surface features at the scan location, and a microelectromechanical systems (MEMS)-based scanner for directing the light.