MSFinals-3000

A 68-year-old male presents with a sudden onset of vision loss in his right eye that lasted for about half an hour. He experienced initial blurring of vision followed by cloudiness and inability to see out of the eye. The patient has a recent history of hypertension and takes atenolol, but is otherwise generally healthy. He drinks modest amounts of alcohol and smokes five cigarettes per day. On examination, his vision is now normal in both eyes with visual acuities of 6/12 in both eyes. His pulse is regular at 72 beats per minute, blood pressure is 162/88 mmHg, and BMI is 30. Cardiovascular examination, including auscultation over the neck, is otherwise unremarkable. What investigations would you order for this patient?