A technique called optical coherence tomography (OCT) may prove to be a simple diagnostic tool in the early stages of multiple sclerosis (MS). An OCT machine can measure any thinning of the retina in people with MS.
The retina is in the back of the eye. It picks up light and sends information to the brain. The retinas of people with MS gradually become thinner, and vision may dim. Since the retina can be seen through the pupil in an eye exam, it's a handy place to assess any nerve damage.
It's even possible that a retinal measurement from an optical coherence tomography machine could pick up this vital information before any other symptoms of MS were evident. To be able to make a diagnosis in the early stages of multiple sclerosis would be a real breakthrough.
"OCT machines already are available. Patients look into a device similar to those that measure vision for corrective lenses. Near-infrared light, which is invisible to the eye, penetrates the retina and provides information on its thickness. The measurement takes a few seconds for each eye."
http://www.sciencedaily.com/releases/2010/06/100607165742.htm