Cause
The optic nerve comprises axons that emerge from the retina of the eye and carry visual information to the primary visual nuclei, most of which is relayed to the occipital cortex of the brain to be processed into vision. Inflammation of the optic nerve causes loss of vision, usually because of the swelling and destruction of the myelin sheath covering the optic nerve. The most common cause is multiple sclerosis or ischemic optic neuropathy due to thrombosis or embolism of the vessel that supplies the optic nerve. Up to 50% of patients with MS will develop an episode of optic neuritis, and 20-30% of the time optic neuritis is the presenting sign of MS. The presence of demyelinating white matter lesions on brain MRI at the time of presentation of optic neuritis is the strongest predictor for developing clinically definite MS. Almost half of the patients with optic neuritis have white matter lesions consistent with multiple sclerosis. Some other common causes of optic neuritis include infection (e.g. a tooth abscess in the upper jaw, syphilis, Lyme disease, herpes zoster), autoimmune disorders (e.g. lupus, neurosarcoidosis, neuromyelitis optica), methanol poisoning, Vitamin B12 deficiency, beriberi, dysautonomia (i.e. autonomic nervous system dysfunction), and diabetes, or an injury to the eye. In neuromyelitis optica higher AQP4 autoantibody levels are associated with the occurrence of optic neuritis.Less common causes are: papilledema, brain tumor or abscess in the occipital region, cerebral trauma or hemorrhage, meningitis, arachnoidal adhesions, sinus thrombosis, liver dysfunction, or late stage kidney disease.
The authors conclude that current evidence does not show a benefit of either intravenous or oral corticosteroids for rate of recovery of vision (in terms of visual acuity, contrast sensitivity, or visual fields). There are a number of reasons why this might be the case. Epidemiology
Optic neuritis typically affects young adults ranging from 18–45 years of age, with a mean age of 30–35 years. There is a strong female predominance. The annual incidence is approximately 5/100,000, with a prevalence estimated to be 115/100,000. Society and culture
In Charles Dickens Bleak House, the main character, Esther Summerville, has a transient episode of visual loss, the symptoms of which  are also seen in people who have optic neuritis. Legal historian Sir William Searle Holdsworth, suggested that the events in Bleak House took place in 1827. In an episode of Dr. Quinn, Medicine Woman ("Season of Miracles", season five), Reverend Timothy Johnson is struck blind by optic neuritis on Christmas Day 1872. He remains blind for the duration of the series. See also
Optic neuropathy
Visual snow

References


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