One of the major reasons for the high failure rate of Alzheimer’s drugs is that we lack techniques to screen people at risk and diagnose the disease at an early stage. Interventions are likely to be most effective when given early, since once neurodegeneration has started and neurons are lost, the damage is irreversible. We need a much better way to identify patients before they display symptoms, so that we can recruit them to clinical studies.

Alzheimer’s disease is characterized by the abnormal production of a protein called amyloid-beta in the brain. This protein exists in small particles that have toxic effects on brain cells and clump together in ‘plaques’. Investigations in Alzheimer’s disease models and donated eyes from deceased patients indicate that increasing amounts of amyloid-beta are also present in the retina as the disease progresses. As a ‘window to the brain’, the retina may open the door to early diagnosis. 

We are developing and implementing a type of eye camera that uses a special method called ‘hyperspectral imaging’. The tool is very sensitive and able to accurately visualize and measure the amounts of amyloid-beta in the retina. The method is not invasive and can be integrated in a routine eye examination.

• Lemmens et al. 2020 (Front Neurosci) Systematic Review on Fractal Dimension of the Retinal Vasculature in Neurodegeneration and Stroke: Assessment of a Potential Biomarker
• Lemmens et al. 2020 (Translational Vision Science & Technology) Hyperspectral Imaging and the Retina: Worth the Wave?

  This review by the team of Prof. Ingeborg Stalmans highlights the clinical applications of a special type of retinal imaging, including promising first results for Alzheimer’s disease diagnosis.

• Veys et al. 2019 (Acta Neuropathol) Retinal α-synuclein deposits in Parkinson's disease patients and animal models

  This review summarizes the current evidence for Parkinson-related protein changes in the retina and their potential as biomarkers.

• De Groef et al. 2018 (J Ocul Pharmacol Ther) Is the Eye an Extension of the Brain in Central Nervous System Disease?