19th July 2023

A 74-year-old man presents to ED with left-sided unilateral visual loss.

A 74-year-old man presents to ED with left-sided unilateral visual loss. He says he did not experience any pain and describes the loss as a ‘curtain coming down’. In total it lasted for 5 minutes. He had no preceding symptoms and denies any other visual symptoms. Fundoscopy is normal. He has a history of hypertension and type 2 diabetes mellitus. He has a 40-pack-year smoking history.

Which is the most likely cause?

Select the SINGLE most appropriate option from the list below. Select ONE option only.