Your optic nerve performs the function of carrying visual information from the eye to the brain. When this optic nerve becomes inflamed, this condition is known as optic neuritis. This condition can flare up suddenly due to an infection or nerve disease. The inflammation can also cause temporary vision loss, which typically happens in only one eye. People with optic neuritis also occasionally experience pain. However, as the patient recovers and the inflammation goes away, the vision is likely to return.
Optic neuritis doesn’t always require treatment and heals on its own. Medications can help in a speedy recovery, in most cases, though it might take up to 12 months to achieve the full recovery of the vision.
Generally, only one eye is affected by optic neuritis. Symptoms may include the following:
- Pain- Most of the people who develop this condition have eye pain which gets worsened by eye movement. Sometimes this pain might feel like a dull ache behind the eye.
- Loss of color vision- Optic neuritis might also affect color perception, and therefore you may notice that colors are appearing less vivid than normal.
- Flashing lights- People having optic neuritis also sometimes report seeing flashing or flickering lights with eye movements.
- Vision loss in one eye- Many people with this condition have at least some temporary reduction in vision, but the extent can vary. Noticeable vision loss generally takes hours or days and improves over several weeks to months. The vision loss might also be permanent for some people.
- Visual field loss- Patients with this condition may also experience side vision loss in any pattern, such as central vision loss or peripheral vision loss.
Causes & risk factors
Optic neuritis might be caused by nerve diseases such as:
- Multiple sclerosis
- Neuromyelitis Optica
- Schilder’s disease
The condition might also be caused by some infections such as:
- Lyme disease
- Viral encephalitis
Other causes of optic neuritis include:
- Sarcoidosis, a condition that causes inflammation in several organs and tissues of your body
- Certain drugs or chemicals
- Guillain-Barre syndrome, a disease in which your nervous system is attacked by your own immune system
- Post-vaccination reaction, i.e. an immune response that may follow a vaccination
Some of the risk factors that can lead to optic neuritis include:
- Age- Optic neuritis generally affects adults between the ages of 20 and 40.
- Race- Optic neuritis is also known to occur more among people of white ethnicity.
- Sex- Women are more likely to develop this condition as compared to men.
- Genetic mutations- There are also certain genetic mutations that can also increase your risk of developing optic neuritis.
You will mostly like to see an ophthalmologist for the diagnosis. He/she will need to know your medical history and perform a routine exam. The following exams might also be required:
- Ophthalmoscopy- In this exam, your doctor will be shining a bright light into your eye and examine the structures located at the back of your eye. This test is meant to evaluate the optic disk, where the optic nerve enters the retina in your eye. The optic disk might also get swollen in over thirty percent of people having optic neuritis.
- Pupillary light reaction test- In this test, your doctor can move a flashlight in front of your eyes to see how your pupils are responding when exposed to bright light. If you are having optic neuritis, your pupils are not going to constrict as much as pupils in healthy eyes would when they are exposed to light.
Your doctor might also recommend other tests such as MRI, OCT (optical coherence tomography, blood tests, or a visual field test.
In most cases, optic neuritis usually improves on its own. However, in some cases, steroid medications are used for reducing inflammation of the optic nerve. Some of the possible side effects of steroid treatment generally include weight gain, mood changes, stomach upset problems, facial flushing, and insomnia.
Generally, steroid treatment is given intravenously, and it helps to quicken the vision recovery, though it doesn’t seem to affect the amount of vision recovery. There is also a treatment known as plasma exchange therapy, which might help some people recover their vision, but it hasn’t been confirmed via any studies that plasma exchange therapy is effective for optic neuritis.
Optic nerve damage- Most people generally experience some level of permanent optic nerve damage after an episode of optic neuritis, but the damage may not lead to any permanent symptoms.
Decreased visual acuity- Although most people are able to regain normal or near-normal vision within some months, a partial loss of color discrimination may persist in some cases. For some people, vision loss might also persist.
Side effects of treatment- Steroid medications that are used to treat optic neuritis can subdue your immune system, which may cause the body to become more susceptible to infections. Other side effects are also there such as mood changes as well as weight gain.