A 44-year-old woman awoke with a scotoma involving the superior visual field of the oculus dexter (OD). On examination, visual acuity was 20/30 OD and 20/20 oculus sinister (OS). She had right optic disc swelling and a partial superior altitudinal visual field defect of the OD. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were normal.

Our patient experienced painless visual loss of her right eye (OD). She had no systemic symptoms such as anorexia, weight loss, jaw claudication, headaches, or scalp tenderness. She took one tablet of sumatriptan, as she thought she had a migrainous aura. Examination was remarkable for decreased visual acuity of the OD, right optic disc edema, and right relative afferent pupillary defect (RAPD). Magnetic resonance imaging (MRI) of the brain and orbits was normal. Magnetic resonance angiography (MRA) of the intracranial vessels showed narrowing of the right proximal (A1) segment of the anterior cerebral artery (ACA). Catheter cerebral arteriography showed an occluded supraclinoid right inferior cerebellar artery (ICA) after the origin of the ophthalmic artery. There was also an occluded right P2 segment with a hypoplastic right P1 segment of the posterior cerebral artery (PCA). ESR, CRP, and plasma homocysteine were normal. She was heterozygous for the methylenetetrahydrofolate reductase (MTHFR) C677T gene mutation.