Multiple sclerosis (MS) is a chronic disease that attacks the nerves in your brain, spinal cord, and optic nerve. It’s considered an autoimmune disease. It causes inflammation and the loss of a protective covering on nerves, known as myelin. This means the electrical impulses, which your body relies on, don’t travel through the nerve properly.
The connection between MS and optic neuritis is the inflammation and loss of the myelin covering of your optic nerve and retina.
Your optic nerve is responsible for transmitting images from your eyes to your brain. Inflammation of this nerve results in optic neuritis. This can cause you to experience vision loss and other troubling symptoms.
Optic neuritis is the first sign of MS in about 15 to 20 percent of people who have MS. The lifetime risk of developing MS after an episode of optic neuritis is about 50 percent according to the Mayo Clinic.
Symptoms of optic neuritis usually occur in one eye and might include:
- pain on eye movement or a dull ache behind your eye
- vision loss or temporary reduction in vision
- loss or dulling of color vision
- reduced side vision
- flashing lights or flickering lights with eye movement
The exact cause of optic neuritis isn’t known. Along with MS, there are other things that have been linked to the development of optic neuritis including:
- neuromyelitis optica, an autoimmune disorder that can affect your optic nerve
- bacterial infections, including Lyme disease, cat-scratch fever, and syphilis
- viruses, like mumps, herpes, and measles
- sarcoidosis and lupus, both of which cause inflammation
- certain medications like quinine and some antibiotics
As mentioned, optic neuritis often occurs in connection with MS. Other factors that increase your risk of optic neuritis include:
- Genetics: Some people have genetic mutations that increase their chance of optic neuritis.
- Sex: Women are much more likely to develop optic neuritis than men.
- Age: Those between 20 to 40 years old have increased risk of developing optic neuritis.
- Ethnicity: Optic neuritis affects Caucasians more often than other ethnicities.
Your doctor will likely refer you to an eye specialist called an ophthalmologist if they suspect you have optic neuritis.
Common tests used to diagnose the condition include:
- ophthalmoscopy, which examines your optic disk for swelling
- pupillary light reaction test, which tests how your pupils respond to light
- MRI scan, which allows for better viewing of your optic nerve
- visual response test, which detects optic nerve damage
Optic neuritis usually improves on its own, and certain medications may help speed your sight recovery if it doesn’t. Steroids are commonly used to treat optic neuritis, and they help reduce optic nerve inflammation.
Steroids may be given intravenously or in pill form. Your doctor may recommend plasma exchange therapy if you experience severe vision loss. If your optic neuritis is believed to be linked to MS, other treatments are available that help slow the progression of MS such as interferon beta-1a and interferon beta-1b.
Monitoring vision for changes associated with optic neuritis is important. Doing so may present a window of time for your healthcare provider to try to prevent or delay MS progression. Your ophthalmologist and neurologist will work together to monitor changes that may affect treatment decisions.
You may experience a flare-up or relapse of optic neuritis if you have MS. This is also known as an exacerbation, which means your symptoms may noticeably worsen or you may experience new symptoms.
Relapse may occur if your optic nerves become inflamed and affect your vision. You may notice only one symptom, or you may have multiple symptoms. For instance, you could experience fatigue or balance problems alongside optic neuritis. This can occur if you have inflammation in different parts of your central nervous system.
See your healthcare provider right away if you have eye pain, experience loss of vision, or see flashing lights. Fast action can help prevent permanent vision loss or other serious health problems.
Be sure to get medical attention if you notice new symptoms, such as a change in how well you can see. It’s also important to be aware of worsening symptoms if you already have optic neuritis, especially if your symptoms aren’t responding to treatment.
Optic neuritis symptoms generally improve in 80 percent of patients over a few weeks according to the Cleveland Clinic. It’s possible to experience only minor visual loss or a full resolution of symptoms.
You may have vision problems in the future if you have optic neuritis but don’t have MS or another underlying condition. Your prognosis for improved long-term vision is better than if you do have MS, however.
Having both optic neuritis and MS may make you more likely to experience recurring symptoms of optic neuritis.