Optic neuritis and multiple sclerosis are separate but related medical conditions. Optic neuritis, an inflammation of nerves in the eye, frequently serves as the first emerging symptom of multiple sclerosis in an individual. In some cases, however, optic neuritis could be an indicator of another medical condition.
The optic nerve is the bundle of fibers that transmits information from the eye to the brain. In optic neuritis, the optic nerve becomes inflamed, leading to loss or blurring of vision that may be temporary or permanent. Many individuals who experience only one episode of optic neuritis eventually regain normal vision. Steroid medications may be prescribed by an individual's physician to increase the speed of vision recovery. Individuals who develop optic neuritis are typically females between 18 and 45, although children are sometimes affected.
Autoimmune disorders, including multiple sclerosis, can be a primary cause of the development of optic neuritis. Multiple sclerosis is a disease in which the individual's own immune system attacks the myelin sheath that coats nerve fibers in the spinal cord and brain. The result is inflammation and damage to the nervous system. Studies have demonstrated that an initial episode of optic neuritis leads to a 50 percent risk that the onset of multiple sclerosis will occur within 15 years. Thus, optic neuritis and multiple sclerosis are cross-referenced in medical literature as interconnected conditions.
Optic neuritis and multiple sclerosis are not linked in every case. In individuals who do not go on to develop multiple sclerosis or another autoimmune disease, optic neuritis could be a result of a viral or bacterial infection, diabetes, vitamin deficiency, or medication side effect. Another possible cause could be exposure to certain toxins, such as lead or arsenic. Undiagnosed tumors or the effects of radiation to the head are less common causes of optic neuritis.
Optic neuritis typically affects the vision in only one eye, although it can occasionally occur simultaneously in both eyes. One symptom might be eye pain that becomes worse with movement of the eye. Vision changes, including blurriness or a change in perception of colors, can affect one small area of vision or the entire eye. Symptoms might develop very quickly and then disappear within a few days. Pain or blurred vision could be intensified by exercise or becoming overheated.
As related conditions that both involve nerve damage, optic neuritis and multiple sclerosis must be diagnosed and monitored by health professionals. Individuals who experience symptoms of optic neuritis for the first time should contact their doctors right away. Those who have already been diagnosed with optic neuritis should alert their physicians if they have worse or different symptoms than usual. Numbness or weakness of the limbs can also signal the need for emergency treatment in individuals with optic neuritis.