Grade 4 Optic Neuritis, CTCAE

**Semantic type:** Finding

**Definition:** Sight-threatening consequences; urgent intervention indicated; best corrected visual acuity of 20/200 or worse in the affected eye: significant visual field loss; marked optic disc edema or enhancement on MRI scan; intravenous steroids indicated; blindness

**Synonyms:** - Grade 4 Optic neuritis