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Structural and functional correlates of the visual system as marker of aging and neurodegenerative changes in the brain

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posted on 2023-11-10, 00:01 authored by Samran Sheriff

Aging is a complex and multifactorial physiological process that is influenced by a multitude of genetic, epigenetic, and environmental factors. In recent years, there has been growing interest in elucidating the relationship between the visual system and brain changes in the healthy aging process as well as in age-related neurodegenerative disorders such as dementia. Thought of as an extension of the brain the retina, offers a unique opportunity to visualise and monitor the health and integrity of the brain non-invasively and routinely. Neuroimaging of the visual pathway can be used to evaluate the relationship between retinal changes and brain imaging in healthy aging participants and in patients with neurodegenerative conditions such as Alzheimer’s disease (AD). This study aims to determine whether visual pathway degenerative changes are predictive of or corelate with brain deficits in aging subjects. The study also investigated how retinal and blood analysis including various genetic alterations correlate with brain structural and neuropsychological measures in healthy aging and AD at-risk individuals. These aims are firstly addressed through undertaking a large-scale meta-analysis to identify the association of various retinal OCT (Optical Coherence Tomography) parameters with AD diagnosis and whether retinal measurements can be used to differentiate between AD and control subjects. Secondly a comprehensive cross sectional clinical study to examine the relationships of retinal structural (OCT) and visual functional (multifocal visual evoked potentials, mfVEP) indices with neuropsychological and brain structural measurements in healthy older subjects was performed. Finally, a genetic analysis was conducted to investigate the relationship of known genetic risk factors for AD- APOE (Apolipoprotein E) ε4 allele and BDNF (Brain derived neurotrophic factor) Met/Met polymorphism, on the visual structural, functional, and vascular indices. 

History

Table of Contents

1. Literature review -- 2. General methods -- 3.Retinal thickness and vascular parameters using optical coherence tomography in Alzheimer’s disease -- 4. Evaluating associations of RNFL thickness and multifocal VEP with cognitive assessment and brain MRI volumes in older adults: optic nerve decline and cognitive change (ONDCC) initiative -- 5. The association of APOE ε4 allele with retinal layer thickness and microvasculature in older adults: optic nerve decline and cognitive change study -- 6. Brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is associated with changes in entorhinal volumes in healthy aging subjects -- 7. General discussion and future directions -- 8. Appendices -- Reference list

Notes

Thesis by publication

Awarding Institution

Macquarie University

Degree Type

Thesis PhD

Degree

Doctor of Philosophy

Department, Centre or School

Macquarie Medical School

Year of Award

2023

Principal Supervisor

Vivek Gupta

Additional Supervisor 1

Stuart Graham

Additional Supervisor 2

Ting Shen

Rights

Copyright: The Author Copyright disclaimer: https://www.mq.edu.au/copyright-disclaimer

Language

English

Extent

207 pages

Former Identifiers

AMIS ID: 248420

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