Optic Neuritis
Optic neuritis is an inflammation of the optic nerve, the collection of nerve fibers that transfers visual information from the eye to the brain. It is understood that the demyelination in optic neuritis is immune-mediated, but the definite mechanism and target antigen(s) are undetermined (Uptodate). The optic neuritis causes a swelling of the optic nerve so its function becomes impaired. The destruction of the protective myelin sheath that covers and insulates the optic nerve, and the direct damage to the nerve axons results in vision loss (Dahl, n.d.). The most common pathologic basis for optic neuritis is inflammatory demyelination of the optic nerve. The pathology is comparable to that of acute multiple sclerosis (MS) plaques…show more content… In the United States, studies have showed the annual incidence of optic neuritis to be as high as 6.4 per 100,000. In the United States, optic neuritis happens more often in whites than blacks (osbome). It is the most common cause of optic neuropathy in young adults. (Mackay) Optic neuritis is the presenting feature of multiple sclerosis in 15 to 20 percent of patients and presents in 50 percent at some time during the time of their illness (Uptodate). Most cases of acute demyelinating optic neuritis occur in women (two-thirds) and characteristically develop in patients between the ages of 20 and 40…show more content… (mayao). Optic neuritis typically is acute and affects one eye. Most people who develop optic neuritis experience eye pain that's worsened by eye movement. Approximately all patients can date the start of symptoms exactly to a specific day; in contrast, patients with optic nerve tumors usually cannot do this. Most people who have a single episode of optic neuritis finally recover their vision. Usually the vision loss often develops within hours to a couple of days and peaking in 1 to 2 weeks. It may vary from a small area of blurring to complete blindness. Optic neuritis patients may have distorted vision, reduced color vision, loss of contrast, and washed-out or less vivid vision than normal. Some people with optic neuritis report seeing flashing or flickering lights.
If a definite cause (such as infection or underlying other disease) is determined, appropriate therapy for that cause can be instituted. (Dahi). Treatment with steroid medications may speed up vision recovery in acute typical optic neuritis, but do not affect the final visual outcome. (Mackay)
As with MS, a genetic susceptibility for optic neuritis is suspected. This is supported by an over-representation of certain human leukocyte antigen (HLA) types among patients with optic