Multiple sclerosis (MS) can cause inflammation and damage to the myelin sheath in the optic nerve. This damage is called optic neuritis. Although the symptoms of optic neuritis tend to subside over time, some people may also benefit from various treatments.
Visual disturbances are among the most common symptom that people with MS have. One study found that optic neuritis is the first sign of MS in about 15–20% of people with the condition.
In this article, we look at the link between MS and optic neuritis, along with its symptoms, causes, treatments, and diagnosis.
What is the link?
MS can cause problems with vision.
MS is a chronic condition wherein the immune system mistakenly attacks the protective myelin sheath that surrounds the nerve cells. These attacks damage these cells, causing inflammation and permanent scarring in the brain, spinal cord, and other nerves.
In MS, optic neuritis occurs when the immune cells attack the healthy, protective myelin sheath that surrounds the optic nerve, mistaking them for invading cells. This causes the myelin to swell up, which can lead to damage of the optic nerve.
The swelling disrupts the signals between the eye and the brain, causing visual disturbances that can include double vision, blurred vision, or blind spots.
The medical community is not exactly sure what causes these attacks or MS itself, though new research aims to explore the genetic and environmental factors behind the condition.
MS is a complex condition that affects different people in different ways. Because of this, people with optic neuritis from MS may have different experiences.
The symptoms of optic neuritis tend to develop quickly, between a few hours and a few days. Adults tend to experience symptoms in only one eye, but severe attacks can affect both eyes. Symptoms tend to gradually disappear over time, but some people may have lingering vision problems after an episode of optic neuritis.
Symptoms of optic neuritis in MS may include:
- blurred vision
- pain when using and moving the eyes
- a dull, aching pain behind the eyes
- trouble seeing to the side of the field of vision
- dim vision
- reduced color vision, or a graying of color
- a blind spot or blank spot in the center of vision
- partial blindness
Temporary blindness is also possible but less common.
The symptoms of optic neuritis tend to come in flares, getting worse for a short time before beginning to get better. Symptoms may also flare up in response to hot or cold temperatures.
In most cases, symptoms will go away on their own with no specific treatment. Doctors may still recommend treatments in some cases, such as if symptoms are very severe.
A doctor may recommend intravenous steroids as a treatment option for MS with optical neuritis.
The symptoms of optic neuritis will usually go away on their own without medical treatment. However, continuing to take regular MS disease-modulating medication will help. Doctors may also recommend additional treatments in some cases to help speed up recovery.
Doctors may recommend intravenous steroids or oral prednisone to help a person recover more quickly. However, this does not work in every case of optic neuritis.
A plasma exchange can help people who do not respond well to steroids, but this can be expensive.
A person who experiences optic neuritis as a new symptom of an MS flare should check in with their doctor to evaluate their current treatment method and explore new solutions.
The inflammation from an MS attack flares up and then subsides with time. The symptoms will likely follow the same pattern. Many people notice that the symptoms gradually get worse for a few days before gradually getting better.
The length of a symptom flare will vary in each case. Although many people will notice their symptoms go away completely within a few weeks, others may have symptoms for a year or longer after an attack.
Catching inflammation in the optic nerve early can help a doctor devise an appropriate treatment plan to help prevent further damage.
Diagnosis typically begins with a physical exam and the doctor asking some questions about the person’s medical history, including any medications they are taking. After this, the doctor will likely refer the person to a specialist called an ophthalmologist.
An ophthalmologist will perform an eye exam to check for issues such as:
- changes in visual acuity
- changes in color perception
- how well a person can view things from the side of their eye
They may also shine a light into the eye to test its reaction.
If they suspect that MS is the underlying cause, the doctor may order an MRI scan. This test creates a detailed scan of the brain to help doctors identify any scarring or signs of inflammation and nerve damage.
Other diagnostic tests for optic neuritis can include:
- blood tests, to search for specific proteins in the blood
- ophthalmoscopy, to check for inflammation in the optic nerve
- a lumbar puncture, also called a spinal tap, to check the fluid in the spinal cord and brain
- a visual evoked response test, to check how quickly the optic nerve sends signals to the brain
MS is not the only cause of optic neuritis. Other possible causes include:
A thorough diagnosis is important in each case to rule out other contributing factors and discover the true underlying cause of the symptoms.
Optical neuritis is a possible complication of diabetes and MS.
Although optic neuritis in MS can affect anyone, some people are at higher risk.
One study found that optic neuritis most often affects young females.
People with other preexisting conditions that affect the eye may also be at greater risk, including those with diabetes or Devic’s disease.
The outlook for people who experience optic neuritis in MS is relatively good. Much of the time, their vision will fully recover with time, with or without additional treatment.
Because MS is a long-term condition, people may be more at risk of similar attacks later on. As MS progresses or a person experiences severe attacks, changes in vision may become permanent.
Managing MS and slowing its progress with medical treatment is important for every person with the condition.
Optic neuritis refers to inflammation in the optic nerve, and it is a common symptom in people with MS. MS is not the only cause of optic neuritis, however, and a thorough diagnosis is important in each case.
Although the attack and its symptoms will eventually subside on their own, doctors may recommend additional treatments to help speed up recovery times. Anyone experiencing optic neuritis from MS should talk to their doctor to review their treatment and make any necessary changes.