A 70 year old female with a history of hypertension and diabetes lost the vision in her right eye (OD), without associated pain, over a period of a few minutes.  

Examination revealed visual acuity of 20/20 OS, but only of hand motion at 2 feet OD.  Both pupils reacted briskly when a penlight was directed OS, but both dilated when directed OD (positive swinging flashlight test, Marcus Gunn pupil, relative afferent pupillary defect/RAPD).  Extraocular movements were normal.   Funduscopy had the following appearance OD: