Permanent inferior binasal quadrantanopsia in pseudotumor cerebri.

A sixty-year old patient had inferior nasal visual field defect in both eyes associated with papilledema. After pseudotumor cerebri was diagnosed and the appropriate treatment begun, the papilledema disappeared, but the visual field defect persisted. This case suggests a revision of the classical concepts concerning the pathogenesis of binasal defects from intracranial causes and emphasizes the risk of loss of vision inherent in long-standing papilledema.