Abstract
PURPOSE: To describe a case of non-arteritic posterior ischemic optic neuropathy (NA-PION). OBSERVATIONS: One 54-year-old male with a history of hypertension and poor blood pressure control suffered from sudden decreases in color vision and vision over five days. On funduscopy, he had mild nasal elevation of the optic disc in the right eye with blurred margins. Retinal examination and fluorescein angiography demonstrated delayed filling of the inferior nasal retinal artery. A magnetic resonance imaging (MRI) scan of the orbit revealed swelling and tortuosity of the right optic nerve, but no evidence of acute ophthalmic artery obstruction. On the basis of the above findings, he was diagnosed with probable non-arteritic posterior ischemic optic neuropathy. CONCLUSION AND IMPORTANCE: NA-PION, an exclusion diagnosis, is a rare ischemic optic neuropathy that typically presents with acute, painless visual loss in one or both eyes. During this clinical scenario, we review considerations for differential diagnosis and useful diagnostic tests for NA-PION.