Spots on retina from eye scan Image: NeuroVision
Preliminary results from an Australian study suggest that retinal imaging may be a practical test for the early detection of Alzheimer’s Disease.
Researchers are recruiting for a clinical study 200 volunteers who are healthy, and are mildly cognitively impaired or have been diagnosed with Alzheimer’s.
They presented findings from the first 40 patients in the trial to the Alzheimer’s Association International Conference in Denmark on 13 July.
Researchers found the level of beta-amyloid protein detected in the eye was significantly correlated with beta-amyloid in the brain and allowed them to accurately identify those with Alzheimer’s.
Beta-amyloid protein is the major component found in sticky plaques that accumulate in the brain many years before AD symptoms appear.
The scientists said eye scans could identify much smaller plaques than those able to be detected in traditional PET brain scans, meaning eye scans could potentially give an earlier indication of AD, up to 20 years before clinical diagnosis of brain damage, and more accurately track an individual’s response to AD treatments.
Biomedical scientist Dr Shaun Frost from the CSIRO (Commonwealth Scientific and Industrial Research Organisation) described how images of a patient’s retina using a US-developed instrument could look for the amyloid plaques.
He said the retinal amyloid imaging test was a potential initial screening that could complement currently used tests and could potentially be delivered as part of regular eye checks.
‘If further research shows that our initial findings are correct it could potentially be delivered as part of an individual’s regular eye check-up,’ he said. ‘The high resolution level of our images could also allow accurate monitoring of individual retinal plaques as a possible method to follow progression and response to therapy.’
The retinal biomarker trial involved two visits by volunteers for retinal fluorescence imaging.
They sat in front of a camera developed by NeuroVision Imaging and between visits consumed a curcumin dietary supplement, which binds strongly to the plaques and fluoresces, making plaques visible as bright spots in the second of the eye scans.
Dr Frost’s team in collaboration with researchers from Edith Cowan University and American company NeuroVision Imaging is conducting the trial with the McCusker Alzheimer’s Research Foundation in Perth.