Optic neuritis (ON) is inflammation of your optic nerve. It can cause vision loss and pain when you move your eyes. As the inflammation goes away, your symptoms will usually get better.
The optic nerve carries visual information from your eye to your brain. ON is when your optic nerve becomes inflamed.
The inflammation can cause vision loss in one or both of your eyes. This loss of vision is usually temporary. In some cases, you may also feel pain when you move your eyes.
ON can flare up due to an infection or nerve condition. Early diagnosis and treatment can improve your outcome. As you recover and the inflammation goes away, your vision will likely return over time.
Whenever you notice changes to your vision, it’s important to get it checked out by a doctor or ophthalmologist.
Sometimes, eye problems can require emergency treatment. Reasons to seek emergency care include:
- severe eye pain
- sudden loss of vision
- sudden changes to your vision, such as blurry vision
If your vision changes are accompanied by symptoms of stroke, such as facial drooping, difficulty speaking, or severe headache, get emergency help right away. Call your local emergency services or have someone help you get to the nearest emergency room.
There are many possible causes of ON. Some cases are idiopathic, which means they have no known cause.
Multiple sclerosis and other nerve conditions
Other nerve conditions that can cause ON include:
- myelin oligodendrocyte glycoprotein antibody disease, a condition that causes nervous system inflammation
- Schilder’s disease, a long-term (chronic) demyelinating condition that begins in childhood
- neuromyelitis optica (NMO) spectrum disorder, a rare condition that can cause inflammation of the optic nerve
ON can also be caused by autoimmune conditions, such as:
- sarcoidosis, a condition that causes inflammation in various organs and tissues
- Sjögren’s syndrome, a disorder that typically affects tear and saliva glands
- systemic lupus erythematosus, a long-term condition that can affect different organ systems
- glial fibrillary acidic protein immunoglobulin G disease, a rare condition
Infections and other causes
Infections that can cause ON include:
- cat scratch fever (Bartonella)
- Lyme disease
- West Nile virus
Other possible causes include:
The symptoms of ON can vary, depending on what’s causing it.
- vision loss in one eye, which can vary from mild to severe
- periocular pain, or pain around your eye that’s often worsened by eye movements
- dyschromatopsia, or the inability to see colors correctly
Other possible symptoms can include:
- changes in the way the pupil reacts to bright light
- photopsia, seeing flashing lights or floaters in one or both eyes
- Uhthoff’s phenomenon, or Uhthoff’s sign, which is when vision worsens with an increase in body temperature
When ON affects one eye only, it’s called unilateral ON. Unilateral ON is more common. But it’s also possible for ON to affect both eyes. This is known as bilateral ON.
Sometimes, conditions other than ON can cause similar symptoms. These include:
- anterior ischemic optic neuropathy, when part of your optic nerve is not getting enough blood
- Leber hereditary optic neuropathy, a type of vision loss that is passed down in families
A doctor can assess your symptoms and use tests to help determine whether you have ON or another condition.
Factors that increase the chance of developing ON
- being 20 to 40 years old
- being assigned female at birth
- having a diagnosis of MS
The risk of developing MS may be higher for people who live in temperate regions, like western Europe and the northern United States.
A doctor will typically begin by asking you about your symptoms and medical history. They’ll then perform a physical exam. To ensure the best treatment, the doctor may perform additional tests to determine the cause of your ON.
Tests for ON can include blood tests or a cerebrospinal fluid analysis.
The doctor may also request imaging tests, such as:
In most cases, you can treat ON with corticosteroids to help reduce nerve inflammation and swelling.
Steroid medication may be taken orally, injected, or administered intravenously. These medications typically come with some side effects, so be sure to talk with your doctor or pharmacist to learn what to expect.
If your ON is the result of another condition, treating that condition will often help to resolve ON. For example, a doctor may prescribe antibiotics if a bacterial infection is causing ON.
Depending on what’s causing your ON, treatments can also include:
- adrenocorticotropic hormone
- intravenous immunoglobulin (IVIG)
- plasma exchange
- interferon injections
Experiencing vision loss can be worrisome, but in many cases, the symptoms of ON are temporary. After the ON episode resolves, most people will not have permanent, severe vision loss. However, it can take some time for your vision to recover, from weeks to months.
Sometimes, ON can lead to complications. It’s less common, but optic nerve damage and serious long-term vision loss can happen.
The eye is a very important part of your body. You should always check vision changes with a doctor. Often, vision loss can be treated before it becomes irreversible.