True regarding amaurosis fugax are all except: March 2010

Ans. B: Binocular lesion Amaurosis fugax is due to a transient decrease in blood supply to the eye or the optic nerve. It occurs commonly when a piece of plaque (embolus) in the carotid aery breaks off and travels to the retinal aery in the eye. Plaque is a hard substance that forms when fat, cholesterol and other substances build up in the walls of aeries. Pieces of plaque can travel through the bloodstream. Vision loss occurs as long as the blood supply to the aery is blocked. Atherosclerosis of the aeries in the neck is the main risk factor for this condition. Risk factors for atherosclerosis include hea disease, high cholesterol, smoking, diabetes, and high blood pressure. Clinical features Monocular transient and recurrent episodes of visual loss characterize this syndrome. Visual loss last for seconds to minutes and then return back to normal. Ophthalmoscopy may reveal an embolus visible within a retinal aeriole or ocular examination may be normal.