Pole to pole.

An otherwise asymptomatic 67-year-old man presented to his ophthalmologist complaining of acute painless "dark area on the right." Visual acuity was preserved, and a single cotton-wool spot was noted in each retina. An inferior right quadrantanopia was evident on automated visual fields, and computerized tomography of the brain confirmed a left occipital stroke. Acute phase markers were elevated, and temporal artery biopsy was consistent with a diagnosis of giant cell arteritis. Isolated retinal cotton wool spots, even in the absence of systemic signs and symptoms, may be suggestive of giant cell arteritis.