Neuro-ophthalmic findings in the visual variant of Alzheimer's disease

Abstract

Purpose To describe the clinical features of a visual variant Alzheimer's disease, a disorder that might be seen by the ophthalmologist with visual symptoms and signs. Design Retrospective case series. Participants Eight patients with Alzheimer's disease presenting with predominantly visual complaints. Methods A retrospective review of patients at a tertiary care academic center seen by the authors from 1999 to 2001 with Alzheimer's disease and predominantly visual complaints. Results Eight patients with the visual variant of Alzheimer's disease were reviewed. All had seen eye care providers before referral to the neuro-ophthalmology clinic for visual complaints but without a diagnosis. Four patients had homonymous visual field loss, and two had presumed cortical visual impairment. Neuroimaging showed either normal brain (1 patient) or atrophy of the parietal or occipital areas but no structural lesions (7 patients). Fluoro-18-deoxyglucose positron emission tomography scans were performed in five of the cases, and all showed hypoperfusion in the parietooccipital areas. Neuropsychologic testing revealed visuospatial deficits in all 5 patients tested. Conclusions Visual symptoms might be the presenting (or rarely only) manifestation of Alzheimer's disease. Clinicians should be aware of the visual variant of Alzheimer's disease. Neuropsychological testing and magnetic resonance imaging (MRI) provide supporting evidence for the diagnosis. Positron emission tomography scans might be helpful in selected cases, especially those with a normal MRI.