Eye and smell tests may reveal early dementia signs

Simple eye and smell tests could be used to spot dementia years before sufferers experience memory symptoms, new research suggests.

Researchers at Moorfields Eye Hospital and the UCL Institute of Ophthalmology found a link between poor cognitive ability – a “clear warning sign” of the early stages of Alzheimer’s – and the thickness of people’s retinal nerves.

In a trial of more than 33,000 participants who had tests on memory, reaction time and reasoning, eye scans showed the nerve fibre layer was “significantly thinner” among those who performed poorly on cognitive tests.

The findings were presented at the Alzheimer’s Association International Conference in Toronto

Other findings presented at the conference suggest smell tests could help detect early-stage Alzheimer’s disease.

Researchers from Columbia University used a 40-item “scratch and sniff” test on 397 elderly adults. Nearly 50 had developed dementia four years on, and researchers found low test scores were “significantly associated” with dementia and Alzheimer’s disease.