Recurrent transient monocular blindness from stenotic central retinal artery.

Transient monocular blindness (TMB) is caused by a temporary reduction of blood flow to the retina or optic nerve. Even though embolism from the ipsilateral carotid artery has been considered the main mechanism of TMB, the vascular pathology remains unknown in many patients. A 42-year-old man presented with recurrent transient visual loss in the left eye for 2 months. The attacks tended to develop more frequently when his head was bent down. Fluorescence angiography during an attack revealed hypoperfusion of the left central retinal artery (CRA) and cerebral angiography documented a focal isolated stenosis of the CRA at the origin. Aspirin and nimodipine reduced the attacks markedly. Stenosis of the CRA may be a cause of TMB. Intermittent vasospasm in addition to static hypoperfusion may have caused TMB in our patient with isolated CRA stenosis.