A 66-year-old man complained of recurrent transient monocular visual loss in his left eye during the climax of sexual intercourse.

The patient had no past medical history related to cardiovascular disease or erectile dysfunction and did not take any medication. He smoked one pack of cigarettes per day and had done so for 25 years. The patient had no history of alcohol or substance abuse, and no family history of cardiovascular disease was reported.

The symptoms started 2 months before the patient was first seen by us, recurring invariably during sexual intercourse, two or three times per week. Each attack of blindness lasted 1–2 min, consisting of monosymptomatic complete visual loss of rapid onset in the left eye only (no light perception). Vision remained normal in the fellow eye. The patient stated that each attack was followed by spontaneous complete visual recovery over a few minutes.

Initial ophthalmological and neurological examinations elsewhere revealed no abnormal findings. Cerebral computed tomography was normal, whereas ultrasonography showed complete internal carotid …