Visual disturbances with focal progressive dementing disease.

Symptoms referable to the visual system may be the earliest and most prominent signs of idiopathic dementing disease (Alzheimer's type) despite the lack of objective signs in the eyes or visual system. Three such patients are described. The first patient, who had ultimately proven Alzheimer's disease, initially complained of poor vision and spatial disorientation. Her course was characterized by progressive topographic agnosia during a ten-year period. The second patient first sought ophthalmic consultation for blurring of vision that subsequently progressed during a six-year period to alexia without agraphia and spatial disorientation. The third patient, who had presumed Alzheimer's disease, initially complained of reading difficulties that prompted several ophthalmic consultations. Her problem was initially one of increasing visual agnosia which, together with other perceptive disturbances, gradually deepened during a period of several years.