Synonyms: ION
A rare inflammatory optic neuropathy characterized by isolated episodes (either single or recurrent) of optic neuritis not associated with other neurological or systemic disease. Patients typically present with subacute unilateral loss of vision progressing over several days to two weeks periocular pain and pain on eye movement (which may precede the onset of visual symptoms) light flashes on eye movement abnormal color vision reduced contrast sensitivity and relative afferent pupillary defect. The optic disc appears swollen in many patients and uveitis may be associated and can be present for years before the onset of optic neuritis.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version May 2026
Newly diagnosed with
Isolated optic neuritis?
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Advocacy Organizations
Siegel Rare Neuroimmune Association
The Siegel Rare Neuroimmune Association (SRNA) is a not-for-profit organization dedicated to the support of children, adolescents, and adults with a spectrum of rare neuroimmune disorders including: Acute Disseminated Encephalomyelitis (ADEM), Acute Flaccid Myelitis (AFM), MOG Antibody Disease (MOGAD), Neuromyelitis Optica Spectrum Disorder (NMOSD), Optic Neuritis (ON) and Transverse Myelitis (TM)
The MOG Project
The MOG Project is devoted to raising awareness, educating doctors, patients and caregivers, advancing research through expert collaboration and fundraising, and providing support and advocacy for our community in hopes of finding a cure.
The MOGAD Initiative for Navigation and Direction (MIND)
Many families in the world are currently diagnosed with myelin oligodendrocyte glycoprotein antibody disease (MOGAD). Being diagnosed with a rare disease such as MOGAD can be challenging, especially if you don't know much about it. MIND transforms complex medical terminology to easy-to-understand information for patients/families, leaving no MOGAD patient in the dark about their diagnosis.
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Clinical Trials
For a list of clinical trials in this disease area, please click here.