optic nerve disorder radiation-induced disorder radiation-induced optic neuropathy https://github.com/monarch-initiative/mondo/issues/10446 MONDO:1060271 An optic nerve disorder caused by radiation necrosis of the anterior visual pathway, occurring as a late complication of radiotherapy for head and neck or intracranial tumours and resulting in acute, painless and usually irreversible visual loss. Onset is typically 10 to 20 months after treatment but ranges from 3 months to 9 years. RION