Optical coherence tomography eye testing is performed typically to detect early signs of eye disease through assessment of the retina, and has been found by the researchers to show that individuals with thinner retinas tend to be at greater risk of developing problems with reasoning and memory.
32,000 individuals aged 40-69 years old participated in this study who had parts of their retinas measured using optical coherence tomography and were also assessed for reaction times, reasoning, and memory. Having the thinnest retinal nerve fiber layer was found to be more likely to fail one or more cognitive test and to be twice as likely to have lower scores in follow up assessments over the next three years.
Retinal tissue deterioration could be reflective of changes occurring in brain vasculature which may play a role in development of dementia, treatments will likely be more effective in slowing or stopping dementia in earlier stages, targeting earlier stages it should be possible to design better clinical trials for treatment.
Optical coherence tomography eye testing alone was noted by the researchers to not be enough to screen for dementia as thinner retinas are not always associated with onset of cognitive decline. Dementia diagnosis should always rely on results from a number of tests. Future investigations should look at how sensitive optical coherence tomography testing may be at helping to identify those at the most risk of cognitive decline.
