A 68-year-old white female presented to her outside ophthalmologist with acute vision loss in the left eye (OS) described as a “green line across the top half of her vision” and dull pain OS. She then experienced progressive worsening of vision OS, pain with chewing, temple pain, and scalp tenderness. The visual acuity was 20/20 in the right eye (OD) and counting fingers at 1/2-foot distance OS. There was a left relative afferent pupillary defect and optic disc edema OS. The right optic nerve was normal, but the cup-to-disc ratio was 0.4 OD.