How eye tests spot dementia

EYE tests can help predict which Parkinson’s disease patients will develop dementia around 18 months later, research has found.

In one study, lead scientist Dr Angeliki Zarkali said: “We’ve found that people with Parkinson’s disease who have visual problems are more likely to get dementia, and that appears to be explained by underlying changes to their brain wiring.

“Vision tests might provide us with a window of opportunity to predict Parkinson’s dementia before it begins, which may help us find ways to stop the decline before it’s too late.”

Her team at London’s Dementia Research Centre, UCL Queen Square Institute of Neurology, studied 77 people with Parkinson’s and found that simple vision tests predicted who would go on to get Parkinson’s dementia after a year and a half.

Those who developed the dementia had losses in the wiring of their brain, including in areas relating to vision and memory.

Meanwhile another study, by the same research centre, took brain MRI scans of 88 people with Parkinson’s and 33 healthy adults.

People with Parkinson’s had a higher degree of decoupling – where connections between regions of the brain are broken – across the entire brain.

Researcher Dr Rimona Weil said of the studies: “Our findings could be valuable for clinical trials by showing that vision tests can help us identify who we should be targeting for trials of new drugs that might be able to slow Parkinson’s.

“If effective treatments are found, these simple tests may help us identify who will benefit from which treatments.”

The studies, supported by several charities, are in the Movement Disorders and Communications Biology journals.