Unilateral occipital infarction: evaluation of the risks of developing bilateral loss of vision

Fifty-eight patients with a unilateral infarction in the superficial area supplied by a posterior cerebral artery were followed (mean: 39.6 months). Thirteen (22.4%) developed cortical blindness associated with a delayed contralateral occipital infarction. Advanced age, general vascular risk, a history of strokes, Sylvian border-zone extension of the initial infarct, and an absence of improvement of initial visual field defects were strongly associated with spread to the other side. The lack of visual field improvement most accurately predicted a high risk of cortical blindness. A careful follow-up and controlled medical therapy is particularly indicated in these patients.