chronic relapsing inflammatory optic neuropathy CRION - autoimmune without sarcoidosis, SLE, MS, NMO or other. Tapering glucocorticosteroid causes relapse - chronic immunosupression is required. azathiorpin, methotrecxate, cyclophosphamid, Ivig. Check: systemic, metabolic, toxic, paraneoplastic causes, anti-MOG, anti-aqp4 IgG