Medical News Today: How does MS affect the eyes?
As with the other symptoms of multiple sclerosis (MS), eye symptoms can appear during a flare and then fade away over time. Treatments may help protect a person’s eyesight, slow the progress of MS, and prevent further damage.
In this article, we look at how MS can affect a person’s vision and the treatment options for these symptoms.
MS and eye problems
Vision problems are a potential early sign of MS.
Multiple sclerosis (MS) is a progressive disease in which the immune system mistakenly attacks healthy nerve cells. In doing so, it damages the protective coating of these cells, which is called the myelin sheath. Damage to these cells can cause permanent scarring in the brain, leading to a range of symptoms.
Although MS affects each person differently, the National Multiple Sclerosis Society (NMSS) note that vision problems are very often the first symptoms that people with MS experience.
When MS affects the nerves in a person’s eyes, it can cause inflammation, leading to symptoms. The official name for the condition is optic neuritis.
A person with optic neuritis may notice various issues with their vision, generally only in one eye. These issues may come on suddenly or slowly. They can be worrying, but they typically fade with time.
People with MS commonly experience some form of vision loss as the disorder progresses.
Vision problems usually affect one eye, and they tend to get worse before getting better. Anyone experiencing these symptoms should contact their doctor immediately, as in some cases, treatment options are available.
Although complete vision loss is possible, it is not as common as other symptoms, such as:
- blurred vision
- loss of color or graying vision
- pain as the eyes move
- partial or total blindness in one eye that gets worse during an attack
- trouble seeing to the side
- dull pain behind the eyes
Eye movement problems
People with MS may experience uncontrollable eye movements called nystagmus.
Nystagmus will not always present the same way, but it often causes one or both eyes to move back and forth repetitively. The person may lose control of how their eye moves in a certain direction. They may also feel as though things are moving when they are not.
The severity of nystagmus can also vary. Some people may experience mild symptoms, while others experience movements that are severe enough to disrupt their vision.
Some people with MS may also experience double vision, or diplopia.
Diplopia occurs when the muscles in the eyes are out of sync because one is not working correctly. As a result, the brain struggles to put together a clear image.
In someone with MS, this occurs when the disorder affects the nerves controlling these muscles.
In the advanced stages, MS may destroy the protective coating around the nerves, leading to permanent changes in eyesight. In a person who regularly experiences vision issues during flare-ups, this may lead to partial or total blindness in one or both eyes.
How long do symptoms last?
Heat may worsen MS symptoms in some people.
MS affects each person differently, so there is no telling exactly how long symptoms will last.
Symptoms should subside as the inflammation in the nerve cells goes away. For many people, this is as little as a few weeks. Others may experience symptoms that last up to a year or more.
Some people may find that their symptoms get worse with heat, for example, after a hot shower or on particularly hot days. A high body temperature from exercise or the flu can also exacerbate symptoms in some people.
Symptoms may also worsen as the person uses or strains their eyes all through the day. Anyone experiencing eye symptoms should take regular breaks throughout the day to rest their eyes and avoid unnecessary strain.
Eye symptoms arise when the immune system attacks the myelin sheath of the nerves that control various aspects of the eye. The type of symptoms that a person experiences will vary depending on which nerves sustain damage.
MS is not the only cause of optic neuritis. Other factors that may cause inflammation in the eyes and result in symptoms include:
Scientists do not fully understand the exact cause of MS. However, there is evidence that some people may be more at risk of developing MS. For instance, the NMSS note that a few environmental factors may increase the risk for this condition, including:
However, an increased risk does not mean that these factors directly cause the disorder.
To properly diagnose MS-related eye problems, doctors will need to rule out other conditions. To do so, they may order tests to check for MS or other issues. These tests may include:
- a vision test with an ophthalmologist
- blood tests
- imaging tests, such as MRI scans
- a visual evoked response test
- a lumbar puncture
Even if the person already knows that they have MS, a thorough diagnosis is important to avoid misdiagnosing another underlying issue.
A doctor may recommend additional medications to relieve certain MS symptoms.
Most vision problems that occur due to MS eventually improve on their own, but people can still find these symptoms difficult to manage. Continuing to take medication to relieve MS symptoms will help. Doctors may recommend additional treatments if a person is experiencing very severe symptoms.
For instance, if a person has severe vision loss, a doctor may recommend treatments that they would otherwise avoid, such as intravenous steroids.
In other cases, simple methods may help. For instance, doctors may give a person with double vision a temporary eye patch. The patch will block out input from one of the eyes, which should correct the double vision.
Some medications may also help reduce the side effects of vision problems until the flare-up subsides.
It is not possible to completely prevent MS damage to the eyes, but people can take steps to reduce the likelihood of it occurring.
People who are prone to flare-ups in their eyes should rest their eyes regularly throughout the day. Doctors may also recommend that people wear glasses with specific prisms in them that help control disturbances in the eye and reduce symptoms.
There may also be a link between vitamin D levels and the severity of flare-ups. A study in the journal Neurology found that there was an association between vitamin D levels and the severity of optic neuritis.
However, this does not necessarily mean that taking vitamin D will result in a person having less severe attacks. Researchers are performing more comprehensive research, but in the meantime, some doctors recommend that their MS patients take vitamin D supplements to support their body.
Anyone who notices new symptoms or whose symptoms begin to get worse should speak to a doctor who can advise on ways to treat or reduce the effect of symptoms.
MS-related vision problems are common, but the condition will not affect everyone in the same way. Many symptoms will go away on their own without treatment, and the overall prognosis is good.
However, as MS progresses, a person’s vision issues are likely to get worse.
Early diagnosis and treatment are important to help reduce symptom severity.