Choroidal Structural Analysis in Alzheimer's Disease, Mild Cognitive Impairment, and Cognitively Healthy Controls.

Abstract

PURPOSE: To assess choroidal structural parameters in symptomatic Alzheimer's disease (AD), mild cognitive impairment (MCI), and cognitively healthy controls. DESIGN: Prospective cross-sectional study. METHODS: Setting: Outpatient neurological disorders clinic. STUDY POPULATION: One hundred and twelve eyes of 67 individuals with AD, 143 eyes of 74 individuals with MCI, and 248 eyes of 137 controls. Individuals with diabetes, glaucoma, or retinal pathology were excluded. OBSERVATION PROCEDURE: High-definition EDI foveal scans were obtained using Zeiss Cirrus HD-5000 AngioPlex (Carl Zeiss Meditec, Dublin, CA). Subfoveal choroidal thickness (SFCT) was measured by two masked graders with a third adjudicator. Total choroidal area (TCA), luminal area (LA), and choroidal vascularity index (CVI) were calculated after image binarization. MAIN OUTCOME MEASURES: Association of choroidal parameters with AD, MCI, or controls using generalized estimating equations, adjusted for age and sex. RESULTS: After adjustment for age, sex, and visual acuity, TCA was significantly greater in AD (ß 2.73, p = 0.001) and MCI (ß 4.38, p < 0.001) compared to controls, LA was significantly greater in AD (ß 1.68, p = 0.001) and MCI (ß 2.69, p < 0.001) compared to controls, and CVI was significantly lower in MCI (ß -0.58, p = 0.002) compared to controls. SFCT was similar among AD, MCI, and controls on multivariable analysis (p > 0.05). CONCLUSIONS: TCA, LA, and CVI may differ between individuals with AD, MCI, and healthy cognition, whereas SFCT may not differ between these groups. TCA, LA, and CVI deserve further study in individuals along the Alzheimer's continuum.