Optic neuritis is an inflammation of the optic nerve, the bundle of nerve fibers that transmits visual information from your eye to your brain. Pain and temporary vision loss are common symptoms of optic neuritis.
Optic neuritis is highly associated with multiple sclerosis, a disease that causes inflammation and damage to nerves in your brain and spinal cord. In some people, signs and symptoms of optic neuritis may be the first indication of multiple sclerosis.
Majority of people with a single episode of optic neuritis eventually recover. Steroid medications may help in speedy vision recovery post optic neuritis.
Precise cause of optic neuritis remains unknown.
The optic nerve carries visual information from the eye to the brain. Swelling of the nerve can occur due to sudden inflammation. The nerve fibers can be damaged and there can be a short or long-term loss of vision.
Conditions that have been linked with optic neuritis include:
- Autoimmune diseases, such as Behcet’s disease and lupus, sarcoidosis
- Cryptococcosis, a fungal infection
- Bacterial infections, including tuberculosis, syphilis, Lyme disease, and meningitis
- Viral infections, including measles, rubella, viral encephalitis, chickenpox, herpes zoster, mumps, and mononucleosis
- Respiratory infections, including Mycoplasma pneumonia and other common upper respiratory tract infections
- Multiple sclerosis
Symptoms may include:
- Loss of vision in one eye in an hour or in a few hours
- Reaction of the pupil to bright light
- Loss of color vision
- Pain when you move the eye
- A complete medical exam can help rule out related diseases. Tests may include:
- Color vision testing
- MRI of the brain including special images of the optic nerve
- Visual acuity testing
- Visual field testing
- Examination of the optic disc using indirect ophthalmoscopy
Complications may include:
- Body-wide side effects from corticosteroids
- Vision loss
- Some people who have an episode of optic neuritis will develop nerve problems in other places in the body or develop multiple sclerosis.
Optic neuritis commonly involves the central area of your vision. However, any area of your vision (your visual field) may be affected. Central vision is the sight which you use for daily activities such as watching television, reading as well as recognizing people and doing close tasks that require detailed vision.
Losing some of your field of view may also mean that you have difficulties with depth perception. This may result in problems related to judging distances and may make doing regular activities such as crossing roads, pouring liquid into a cup or going up and down stairs, more difficult.
Some people with optic neuritis describe seeing flashing or flickering lights. You may also find that your colour vision is affected. Certain colour such as red, may appear faded or less bright than usual. In addition, you may notice that you are less able to pick out objects against their backgrounds, particularly if they are a similar shade or colour, for example reading yellow text on a yellow background. This is described as having reduced contrast sensitivity.
Temporarily the vision in the affected eye may also worsen due to heat but this may improve once cooled down.
When your vision is first affected it may be common to experience discomfort or pain around your eyes, which might get worse when you move your eyes. This pain should not be so great that it stops you sleeping at night. There may be another cause if the pain is much worse and then it is important to consult an eye specialist. The pain normally only last a few days.
Optic neuritis commonly involves the central area of your vision. However, any area of your vision (your visual field) may be affected. Central vision is the sight which you use for reading, watching television, using a computer as well as recognising people’s faces and doing close tasks that require detailed vision.
Losing some of your field of view may also mean that you have difficulties with depth perception. This may cause problems with judging distances and may make daily activities such as crossing roads or pouring liquid into a cup or going up and down stairs or curbs, more difficult. You may need to take more time when doing these things.
Some people with optic neuritis describe seeing flashing or flickering lights. Colour vision may also be affected. Bright colours such as reds, may appear faded. Additionally, a person may experience a reduced ability to pick out objects against their backgrounds, particularly if they are of the same shade. This condition is described as reduced contrast sensitivity.
Heat may temporarily worsen the vision in the affected eye but this generally improves once the eye is cooled down.
When initially the vision is affected, experiencing pain or discomfort around eyes may be common, which might worsen on moving the eyes. It will normally only last a few days.
Early improvement happens as inflammation goes down and your optic nerve begins to recover. Vision recovery is likely to happen quickly at first, but may gradually slow down. Your vision may continue to improve over a period of six months to a year and by about nine to twelve months it is likely to be clear what the final recovery of your vision is.
Predicting how good the vision will be in the long-term, is difficult. If the eye is affected by optic neuritis for the first time, then the vision might improve even if the effect was severe to begin with. Around 75% of people diagnosed with the most common type of optic neuritis, eventually experience a very good long term recovery.
Following an episode of optic neuritis the ophthalmologist or optician may be able to see some lasting damage to the optic nerve when they examine the back of your eye. This lasting damage is known as optic atrophy.
For some people this could mean at some permanent visual changes might remain even after an initial improvement. These can include colours appearing faded and difficulty identifying different shades of colour.
You may also notice that your vision isn’t as sharp as it used to be and/or that you struggle with your perception of depth or movement. These symptoms can be present even if your central vision is good when tested by your ophthalmologist or optician.
In some rare cases, no significant improvement in vision may be achieved and a reduced vision may still persist even after improvement in inflammation occurs. Despite a person having some optic atrophy which is diagnosed during eye examination, it is possible not to have any noticeable lasting symptoms or changes in the vision.
A careful history related to fever, neurological symptoms, recent illness, or recent immunizations is helpful. The ophthalmologist checks vision and function of optic nerve such as color vision, pupil reactions and peripheral vision. Examination of the optic nerve with ophthalmoscopy for dilated blood vessels and swelling is also done. Other tests performed may include a spinal tap, an MRI, and blood tests.
Fortunately, in majority of cases, children with optic neuritis recover most of their vision. This usually occurs suddenly and treatment may not be needed. Recovery usually begins within a few weeks, and can continue for several months. Administration of intravenous corticosteroids may help in speedy vision recovery, but mostly do not result in improvement of the final visual outcome. Unfortunately, a small percentage of children do not recover vision.
Treatment of Optic neuritis
Optic neuritis treatment in India at Sanjeevan consists of improving the blood circulation to the optic nerve and reducing the inflammation. The increased blood circulation helps in the conditioning of the optic nerve which allows it to function better. After treatment patients report to see better colour vision and sharper vision. With the treatment the pain caused to the patients is highly reduced. Ultimately deterioration of the vision can be recovered.