Eye Test May Diagnose Multiple Sclerosis
No single test can by used, by itself, to diagnose multiple sclerosis. Now researchers have discovered a quick eye test that has the potential to diagnose multiple sclerosis in its very early stages and also monitor the effectiveness of therapy.
Multiple sclerosis is a chronic, often disabling disease that affects the central nervous system, resulting in symptoms that can range from numbness in the limbs to paralysis or blindness. The severity, progression, and specific symptoms associated with multiple sclerosis are unpredictable and differ from person to person.
According to the National Multiple Sclerosis Society, to make a diagnosis of multiple sclerosis a physician must find evidence of damage in at least two separate areas of the central nervous system (e.g., brain, spinal cord, optic nerves) and also find evidence that the damage occurred at least one month apart. In addition, physicians must rule out all other possible diagnoses. Physicians frequently turn to magnetic resonance imaging (MRI), visual evoked potentials (VEP), and cerebrospinal fluid analysis to aid in the diagnostic process.
In a multicenter study, investigators at UT Southwestern Medical Center found a quick, painless measurement technique, called optical coherence tomography (OCT), which reliably measures thinning of the retina in people who have multiple sclerosis. Retinal thinning is known to occur in multiple sclerosis, and this study was the first to track this thinning process over time in a single group of patients.
The study included 299 patients with multiple sclerosis who were tracked for six months to 4.5 years. The researchers learned that the retinas of the multiple sclerosis patients thinned significantly over time, often with accompanying lost visual sharpness. Because the retina is easy to visualize through the pupil, ophthalmologists can readily measure and assess nerve damage.
According to Dr. Elliot Frohman, professor of neurology and ophthalmology, director of the Multiple Sclerosis Clinical Center at UT Southwestern, and co-senior author of the new study, OCT “has the potential to provide a powerful and reliable assessment strategy to measure structural changes in the central nervous system,” both to aid diagnosis and to assist in clinical trials when tracking potential treatments to determine if they can prevent deterioration or nerve function or restore it.
OCT is easy to use, sensitive to changes over time, reliable, and machines are already available. Measurements take only a few seconds per eye, and the technique can be used along with current clinical measures.
It is hoped that in the future, ophthalmologists will be able to use OCT during a routine eye examination and be alerted to the possibility of multiple sclerosis. Frohman notes that use of the new eye test may be capable of detecting signs of multiple sclerosis before individuals develop other symptoms. Future studies are necessary to determine whether OCT is capable of characterizing the effectiveness of treatments.
National Multiple Sclerosis Society
UT Southwestern Medical Center