Optina Diagnostics' Cerebral ß-Amyloid Status (CAS) Test

This non-interventional, cross-sectional study is designed to validate a novel diagnostic test, the Optina Diagnostics' Cerebral ß-Amyloid Status (CAS) test, for the detection of phenotypic changes in the retina that correlate with likely PET amyloid status (positive or negative). The CAS test is an adjunct to other diagnostic evaluations, and is indicated for use with the Optina Diagnostics' MHRC for imaging the retina. The study objective is to characterize the performance of the diagnostic CAS test in the target population of adult patients fifty (50) years and older with cognitive impairment, who are being evaluated for Alzheimer's disease (AD) and other causes of cognitive decline. The data generated in this study will provide evidence to be used in the assessment of the benefits and risks associated with use of the device in the intended population. The primary endpoint is to demonstrate accuracy of the Optina Diagnostics' CAS test compared to amyloid-PET status, as determined by a majority of three (3) qualified, independent PET Readers.