Idiopathic optic neuritis is a demyelinating lesion of the optic nerve, one of the most common initial signs of multiple sclerosis! It is the most common acute optic nerve disease in the young and middle-aged population (under 45 years of age). I. Epidemiological features: 1. age of onset, between 20 and 50 years old, mean age 30-35 years old; 2. common in women, male to female sex ratio 1/3; 3. annual incidence rate 1-5 per 100,000 people; 4. prevalence rate close to 115 per 100,000 people. Main symptoms: 1. Unilateral periorbital pain or discomfort, which can be spontaneous or aggravated by eye rotation, occurs in about 90% of patients and can precede or be simultaneous with vision loss; 2. The main signs: 1, relative pupillary afferent disorder; 2, central visual acuity may be decreased or normal; 3, optic neurological visual field defect; 4, decreased contrast sensitivity; 5, normal optic disc in 2/3 of patients, optic disc edema in 20-40% of patients, but optic disc or peri-disc hemorrhage is rare; 6, mild vitreous cells; 7, peripheral retinal vein sheath. Optic disc edema in idiopathic optic neuritis IV. Diagnostic criteria: 1. Acute visual loss with or without ocular pain and optic disc edema; 2. Visual field abnormalities associated with optic nerve injury; 3. Presence of at least one: relative afferent pupillary dysfunction, VEP abnormalities; 4. Exclusion of other optic neuropathies, such as ischemic, compressive, infiltrative, traumatic, toxic, nutritional-metabolic, genetic; 5. Exclude optic cross, optic bundle, and optic center lesions; 6. Exclude other ophthalmic diseases, such as anterior segment disease, retinopathy, macular lesion, glaucoma, etc.; 7. Exclude non-organic vision loss. In addition, infectious optic neuritis and autoimmune optic neuropathy must be excluded. Optic neuritis has a self-healing rate of up to 90% without any treatment and can be restored to 20/40 or better vision within a few weeks. Natural course of disease: 1. deterioration of vision, a few days to two weeks; 2. recovery of vision, beginning about three weeks after the attack, with rapid initial recovery; 3. near-complete recovery of vision about five weeks after the attack; 4. total time course of vision recovery, about one year. The five-year incidence of MS is over 31%. The ONTT (Optic Nerve Treatment Study) was a multicenter randomized controlled clinical trial of 389 cases of isolated acute unilateral optic neuritis, randomized to methylprednisolone intravenous, prednisolone oral, and placebo. Oral treatment not only did not improve visual recovery, but also increased the risk of reoccurrence. Intravenous treatment, although not improving visual improvement, accelerates visual recovery, relieves pain, and reduces the risk of multiple sclerosis. According to ONTT, the recommended treatment regimen for optic neuritis: methylprednisolone 1 g/d IV for 3 days and prednisolone 1 mg/kg orally for 11 days, reduced to 40 mg 1 day and 20 mg 1 day. CHAMPS is a multicenter, randomized, double-blind, placebo-controlled clinical trial of high-dose hormone shock therapy combined with interferon-beta-1a 30 ug given once weekly intramuscularly in patients with optic neuritis at high risk of developing multiple sclerosis, which significantly reduced the risk of developing multiple sclerosis. Therefore, interferon-beta is the drug of choice for multiple sclerosis disease modification.