Ocular changes in Alzheimer’s disease

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.