Less reflected light in the eye linked to dementia in older adults
Higher scores indicating less reflected light were associated with 2.21 times the odds of existing dementia in one retinal region.
In an observational study, 857 Japanese residents aged 65 or older underwent eye and dementia examinations in 2022–2023. Researchers measured light reflected at different wavelengths from four regions of the retina, the light-sensitive tissue at the back of the eye. They used these measurements to build scores, with higher scores indicating lower overall reflection.
Higher scores were associated with existing dementia in every region. The strongest links involved the lower outer region and the four regions combined. A separate scan measured the thickness of a retinal layer. High scores together with thinning of that layer were associated with higher odds of dementia in the lower outer region and the combined analysis.
Why it matters
The work addresses whether eye imaging may provide information about changes associated with dementia in later life.
Caveats
This cross-sectional observational study cannot show cause and effect or whether the scans predict future dementia. The researchers developed the scores using dementia data and reported only internal validation.
The paper
Kyushu University
Scientific Reports, 16 Oct 2026, Open access, CC BY-NC-ND
