Choroidal thinning: Alzheimer's disease and aging

INTRODUCTION: The purpose of this study was to measure and to compare macular choroidal thickness (CT) between patients with mild Alzheimer's disease (AD), patients without AD, and elderly patients. METHODS: CT was measured manually in 13 locations at 500-μm intervals of a horizontal and a vertical section from the fovea. Linear regression models were used to analyze the data. RESULTS: Fifty patients with a diagnosis of mild AD (73.1 years), 152 patients without AD (71.03 years), and 50 elderly without AD (82.14 years) were included. In the AD patients, CT was significantly thinner in all 13 locations (P < .001—comparing with age-match group), and comparing with the elderly group, a more pronounced difference was found in two locations temporal to the fovea. DISCUSSION: Patients with AD showed a significant choroidal thinning even when compared with elderly subjects. The reduction of CT may aid in the diagnoses of AD, probably reflecting the importance of vascular factors in their pathogenesis.