Page 40 - GTM-3-3

Global Translational Medicine

REVIEW ARTICLE
Ocular changes in Alzheimer’s disease

Trinita Jude Hamilton and Bettina E. Kalisch*
Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada

Abstract

Alzheimer’s disease (AD) is an incurable, irreversible condition that bears a large global
burden. An early diagnosis is imperative to allow the maximum time for treatment
interventions. The eye’s involvement has been identified in AD, making it a promising
option for a non-invasive early diagnostic and screening tool. The pathology of
AD observed in the brain such as amyloid beta (Aβ) plaques and phosphorylated
tau have been mirrored in the retina. There is also evidence that AD pathology in
the retina precedes the onset of symptoms and the deposition of plaques in the
brain. It is estimated that Aβ burden results in structural changes in the eye such as
degeneration of the retinal nerve fiber layer, thinning of the macula, reduced blood
flow rate, and thinning of the choroid. These structural changes can be observed
using non-invasive imaging techniques such as optical coherence tomography. This
review examines the existing literature on AD pathology in the retina and discusses
the possibility of using retinal imaging techniques to screen for AD.

Keywords: Alzheimer’s disease; Ocular abnormalities; Amyloid beta; Tau; Retina; Choroid;
Non-invasive diagnosis

*Corresponding author:
Bettina E. Kalisch 1. Introduction
(bkalisch@uoguelph.ca)
Alzheimer’s disease (AD) is an irreversible neurodegenerative disorder recognized
Citation: Hamilton TJ, Kalisch BE. 1,2
Ocular changes in Alzheimer’s by the World Health Organization (WHO) as a global public health concern. AD is
disease. Global Transl Med. characterized by progressive memory loss, cognitive decline, behavioral dysfunction,
2024:3(3):4094. disorientation, and visual impairments. In the advanced stages, individuals struggle
3
doi: 10.36922/gtm.4094
to perform activities of daily living, and it can ultimately result in death. At present,
3,4
Received: July 1, 2024 there is no cure for AD, and available treatments are limited in their effectiveness due to
Accepted: August 27, 2024 5 6
Published Online: September 13, late diagnosis. Early detection and diagnosis are crucial in providing timely treatment
2024 and there has been growing interest in exploring the potential connections between AD
5
Copyright: © 2024 Author(s). and ocular manifestations. This review provides an overview of the pathology of AD,
This is an Open-Access article discusses the presence of similar pathology in the eye along with the resulting ocular
distributed under the terms of the changes, and describes the techniques for screening the eye that could potentially be
Creative Commons Attribution
License, permitting distribution, used to diagnose and monitor AD progression.
and reproduction in any medium,
provided the original work is 2. AD
properly cited.
2.1. Epidemiology
Publisher’s Note: AccScience
Publishing remains neutral with AD is the most common cause of dementia and according to the WHO, 50 million people
regard to jurisdictional claims in 2,7
published maps and institutional are living with dementia around the world. As life expectancy and the proportion of
2
affiliations. the aging population increase, this number is predicted to triple by 2050. Approximately

Volume 3 Issue 3 (2024) 1 doi: 10.36922/gtm.4094