Normal Cognition

This study aims to develop and evaluate biomarkers using non-invasive optical coherence tomography (OCT) and OCT angiography (OCTA) as well as ultra-widefield (UWF) fundus photography to assess the structure and function of the retinal and choroidal microvasculature and structure in persons with mild cognitive impairment (MCI) and Alzheimer's Disease (AD), Parkinson's Disease (PD), or other neurodegenerative disease, diseases as outlined.

Population aging is reshaping societal dynamics and presents significant global challenges. By 2050, it is projected that 1.6 billion people worldwide will be over the age of 65. Given that aging is the primary risk factor for many common chronic diseases, reducing the burden of age-related illnesses and promoting healthy aging have become critical public health priorities. Notably, Hong Kong has one of the largest proportions of elderly and the highest life expectancy in the world. Dementia, particularly Alzheimer's disease (AD), is a multifaceted condition influenced by both biological and behavioral factors. There is a paucity of robust, community-based prospective data in ethnic Chinese populations that integrate clinical and cognitive measures with objective biomarkers and neuroimaging, especially at earlier stages such as mild cognitive impairment (MCI) and early AD. This community-based project aims to establish a cohort of elderly in Hong Kong, with longitudinal follow-up for 2-3 years. A key strength of this research is the incorporation of a panel of blood biomarkers, which will provide a less invasive and more affordable screening tool to identify Alzheimer's disease at a much earlier stage in the community. Additionally, through benchmark with MRI and PET imaging gold standard, these biomarkers have the potential to predict the conversion risk 1) from clinically normal to mild cognitive impairment and Alzheimer's disease (AD dementia); 2) from clinically MCI to Alzheimer's disease (MCI-AD dementia) or remain static; and differentiate non-AD dementia from Alzheimer's disease (dementia-AD). Collectively, these data will facilitate monitoring of aging processes and cognitive decline, help to identify candidate modifiable factors associated with resilience, and generate a de-identified, Chinese-specific resource to advance healthy aging in Hong Kong.