Optic Neuritis Definition, Reason, Symptoms, Treatment & Prevention
Understanding
Optic neuritis is a condition where there is inflammation of the optic nerve, which is a very important nerve and plays a role in sending information from the eye to the brain about what is being seen. Pain and temporary loss of vision in one eye are characteristic symptoms of optic neuritis.
Optic neuritis is associated with a condition called multiple sclerosis, a disease that causes inflammation and damage to the nerves in the brain and spinal cord. Signs and symptoms of optic neuritis may be an early indication of multiple sclerosis, or they may develop late in the course of multiple sclerosis.
In addition to multiple sclerosis, optic neuritis can also occur with other infectious or immune diseases, such as lupus.
Symptom
Optic neuritis generally affects one eye. Signs and symptoms that occur can include:
- Painful. Most individuals who experience optic neuritis complain of pain in the eye which is exacerbated by eye movement. Sometimes, the pain feels like a dull ache behind the eye.
- Decreased vision in one eye. Most individuals experience at least a temporary loss of vision, but the degree of loss can vary.
Significant visual impairment generally develops over hours or days and improves over weeks and months. Vision loss can be permanent in some cases.
- Decreased field of view. Visual field loss may occur, in an erratic pattern.
- Decreased color vision. Optic neuritis can affect color perception, and individuals experiencing it may feel that colors don’t appear as bright as before.
- a flash of light. Some individuals who have optic neuritis report experiencing flashes of light with the movement of the eyeball.
Reason
The cause of optic neuritis is still not known with certainty. However, this condition is believed to develop when the body’s immune system attacks the component that surrounds the optic nerve called myelin.
Furthermore, this can cause inflammation and damage to the myelin. Myelin’s function is in the rapid transmission of electrical signals from the eye to the brain, where they are converted into visual information. Optic neuritis impedes this process and affects vision as a result.
Several autoimmune conditions are associated with the occurrence of optic neuritis:
- Multiple sclerosis. Multiple sclerosis is a disease in which the body’s immune system attacks the myelin that surrounds the nerve fibers in the brain and spinal cord. In individuals with optic neuritis, the risk of developing multiple sclerosis after one episode of optic neuritis is about 50 percent.
- Optic neuromyelitis. In this condition, recurrent inflammation can occur in the optic nerve and spinal cord. Optic neuromyelitis is similar to multiple sclerosis, but less commonly causes damage to the nerves in the brain.
Other factors that are associated with the occurrence of optic neuritis are:
- Infection. Bacterial infections, including Lyme disease or syphilis, and viral infections such as measles, mumps, or herpes, can increase your risk of developing optic neuritis.
- Another disease. Diseases such as sarcoidosis and lupus can cause recurrent optic neuritis.
- Drugs. Several classes of antibiotic drugs are associated with the development of optic neuritis.
Diagnosis
The diagnosis of optic neuritis can be determined from a detailed medical interview, direct physical eye examination, and certain supporting examinations.
Some eye examinations that can be done are:
- Routine eye examination. This examination can include a vision check, color perception check, and visual field check.
- Examination using an ophthalmoscope. In this examination, the doctor examines the structures behind the eyeball, including the optic disc, which is where the optic nerve and retina connect to the eye. The optic disc may become swollen in some people with optic neuritis.
- Pupillary light reaction test. The doctor may shine a light or flashlight in front of the eye to see how the pupils react when exposed to light. The pupil of an eye with optic neuritis does not show the same light response as a normal eye.
Several investigations that can be performed to determine the diagnosis of optic neuritis include Magnetic Resonance Imaging (MRI) examination, laboratory blood tests, or Optical Coherence Tomography (OCT) examination.
Handling
Optic neuritis can get better on its own. In some cases, steroid-type medication can be used to reduce the inflammatory process in the optic nerve. Possible side effects of taking steroids include weight gain, mood swings, facial flushing, stomach pain, and trouble sleeping.
Steroid treatment is generally done intravenously (through a vein). Administering intravenous steroids can speed up the process of recovering vision, but it doesn’t necessarily affect the level of vision that can return.
Prevention
In someone who has optic neuritis, beta interferon drugs can be prescribed by a doctor to delay or prevent multiple sclerosis.
Drugs that are given by injection can be prescribed for individuals who have a high risk of developing multiple sclerosis. Some of the side effects that can occur include depression, irritation at the injection site, and symptoms of a cold cough.