There are neurological disorders such as Multiple Sclerosis that can affect a person's eyesight. This Q"A addresses the association between the nervous system and vision as well as neurological disorders that present with changes in a person's vision. Dr. Robert Shin, a neuro-ophthalmologist and associate professor of neurology and ophthalmology at the University of Maryland School of Medicine.
People know about ophthalmologists treating the eye and visual problems and people know about neurologists treating issues with the brain. A neuro-ophthalmologist is right in the middle, they treat brain issues that affect vision.
There are a lot of different disorders that affect vision. Some of the common things are stroke, aneurysms and brain tumors. They can all present with visual problems. There are also other disorders like thyroid eye disease, myasthenia gravis and multiple sclerosis.
It's an immune system disorder. The immune system is designed to protect us from infection, but sometimes it's confused and can attack our bodies. In multiple sclerosis, our systems attack our brain, spine and optic nerves. There are many different symptoms with anything that the brain or spinal cord is responsible for. That includes weakness, sensation such as numbness or burning pain, trouble with walking or balance and of course, visual problems.
That's exactly true. We don't know why, but MS affects people in a younger age group. The average age of diagnosis is between 20 and 40 years of age. In addition, it does affect women more than men. There are a lot of men who have MS, but two to three times as many women are affected.
For a significant number of patients, the first inkling that they have MS is a visual problem. Easily a quarter up to half of MS patients might actually present for the first time with some type of visual problem. Almost all MS patients have some type of visual disturbance in their lifetime.
It's not uncommon for patients to have double vision. The reason you're seeing more than one image is because the eyes aren't working together. Patients may also have shaking vision where patients have trouble reading or watching television because the image is shaking due to the MS. One of the most common vision problems people with MS present with is losing vision in one eye and that is called optic neuritis.
One of the hallmarks of multiple sclerosis, even the name multiple sclerosis itself, is presenting with different events, multiple times, during the course of their disease. We call that attack, relapse, and exacerbation. Any individual system may get better within weeks to months, but the issue is that sometimes other symptoms come as well. They can be short lived, but the issue is that you may have many different symptoms.
Our eyes are like cameras. The eyes are in the front, seeing the world, but they have to transmit that information back to the brain which allows us to see things. So if we have a camera capturing the image, the optic nerve is the cable that connects the eye to the brain. If the optic nerve becomes inflamed due to multiple sclerosis, we refer to that as optic neuritis.
Optic neuritis is a specific description of inflammation of the optic nerve. If it happens, that can be one of the multiple things that characterizes multiple sclerosis. However, it is possible to have optic neuritis by itself. You don't necessarily treat optic neuritis because it usually gets better on its own. However, we frequently use steroids because they offer instant relief.
If you have optic neuritis, there's a chance you could have multiple sclerosis, but really the hallmark of multiple sclerosis is multiple episodes over time. By definition, if you had a single event, you can say that technically, you don't have multiple anything at that point. But the question is will you go on to have other issues, that's where the challenge is in diagnosing.
We often use MRI, which is a non-invasive way to image the brain. It seems counter intuitive that if you come to my office with optic neuritis that we want to take a picture of the brain, but the reason for this is that we've learned that if you have optic neuritis with lesions or white spots that look like plaque, then you're risk of developing MS is much higher than if you had optic neuritis and a normal MRI.
They're good and getting better. When I was in training there was no treatment for MS at all. In the past 10 or 15 years, we've made tremendous strides in treating multiple sclerosis and there are more and more treatments and they are getting more and more effective. As far as treating the vision specifically, the MS medications unfortunately cannot undo damage that has already been done. MS medications are designed to prevent additional attacks.
If you've had an optic neuritis, you're probably going to do pretty well. They key is to consider MS medications to prevent you from having additional MS related symptoms such as weakness, numbness, imbalance, or other visual symptoms.
There is actually an oral medication on the horizon. A first we had no treatment of any kind, then we got better at treating it, but they were all injectible therapies. It's very exciting because we're seeing more and more pills for MS being developed and they may be even more effective than the first generation treatments.
Absolutely. Most patients will see an eye doctor first, but it's important to see a neurologist if it looks like you have optic neuritis. Sometimes, optic neuritis signals MS and the earlier you're treated for MS, the better. If you are experiencing visual symptoms that could be optic neuritis, you should see a physician because we really want to do our best to prevent future problems.
Humans are visual animals. We like to explore the environment visually. We have two eyes that work like cameras, but there's a lot of neurologic machinery processing the images.
Vision leaves the eyes and travels through the optic nerves and radiates through most of the lobes of the brain. We start with the front, obviously with the eyes, but the pathway travels through the entire brain all the way to the visual center, the occipital lobe, located at the back of the head. There's a lot involved in vision. Imagine if you had two different cameras, you have to make sure they're pointing at the same thing or you see more than one image. There's also a lot of coordination of the eyes in terms of improvement and integration of taking the two slightly different images and putting them together so when we look around, we see only one image.
A migraine is an interesting phenomenon. I think a lot of people think of migraines as being synonymous with headaches and that's not exactly correct. A migraine is really a neurologic brain phenomenon and is often associated with visual disturbances. Some people will have an aural warning. They may notice blurring, sparkles, flashes or zigzags in their vision and that's a signal that a headache is coming on. That's a classic migraine, when you're headache is preceded by visual symptoms.
Some people can have just the visual symptoms without the pain and it's counter intuitive because most people think migraine means headache. Some patients come to my office with migraine phenomenon, but no headache. They just have visual symptoms like blurring, seeing gray dots or the sparkle of vision. We call this an acephalgic migraine, or a migraine with no headache.
In general migraines hurt and they're uncomfortable. Thankfully, they are limited and treatable and don't usually leave behind any significant neurologic symptoms.
The common one would be stroke. Sometimes aneurysms or brain tumors can cause it and even a brain infection, if it affects the right part of the brain, can result in visual problems.
In general I would say if anyone is having a visual problem, the first stop needs to be with an eye doctor. My focus is on visual problems due to brain issues, but there are visual problems due to eye issues such as cataracts, glaucoma or astigmatism. The first step is to see an eye doctor. If the eye doctor examines the eye carefully and sees that everything in the eye itself appears to be fine, then you should consider the possibility that the visual problem is a due to a neurologic cause.
A lot depends on what the visual problem is. For example with optic neuritis, there are treatments that help and treatments that prevent future attacks. On the other hand, sometimes MS, strokes or aneurysms can cause double vision or misalignment of the eye. In that case the treatment is geared toward getting the images back together. That can be done by using special prisms in the glasses to realign the images and occasionally asking a surgeon to help straighten out the eyes.
Sometimes we'll use the quick trick of covering one eye because if you cover one eye, you can't have double vision anymore. You can take advantage of the phenomenon, especially if someone developed blurred or double vision because there are only two possibile causes.
One possibility is that the images are blurred or doubled because the eyes are not aligned well and if that's the case, then it's a neurologic problem. The other possibility is that the blurring or double vision is due to a problem in the eye like a cataract or a retinal detachment. One trick we use is to ask the patient to cover one eye or the other to see if that helps the symptoms. If someone's eyes are misaligned and they have double vision, when you take away the other eye, you only see one image. If I had a cataract in the left eye that made things look blurry and doubled, then covered the right eye and things are still blurry and doubled, then there's a problem in that eye.
There are also some forms of vision therapy. If you have loss from a stroke and have a field of vision problem, there are some strategies to try to help your brain retrain and regain some of the lost visual function.
It's called presbyopia. With a camera, I can take the lenses and move them. Our eyes don't have the ability for the lens to move, but what our eyes do have is a muscle that changes the shape of the eye. The lens is made of a clear and flexible material. When we're younger, let's say less than the age of 40, our eyes are able to change the shape of the lens. Once you hit 40, the lens doesn't want to change shape as much. For most people, they have more and more trouble focusing on things up close and this is the phenomenon where we hold things far away until eventually, you can't hold them far enough away. That's when people start wearing reading glasses which are really just magnifiers. If you're nearsighted and lived your life wearing glasses, you may discover that you can take your glasses off and see things up close.