Scientists Say Retina Exams in Middle Age May Help Predict Alzheimer's
Michelle Milliken
To diagnose Alzheimer's, a patient undergoes various cognitive tests and brain scans. Generally, these tests don't occur until someone is experiencing symptoms that could be a sign of the disease. Researchers in New Zealand are hoping that the condition could be predicted decades sooner, using retina exams.
A team from the University of Otago has been studying whether the retina can indicate cognitive change earlier in life, years before the symptoms of 'diseases of old age' begin to develop. In a study of more than 800 people, the researchers discovered two ways in which the retina may be able to do so. The findings were published in JAMA Ophthalmology.
The researchers say this discovery could help doctors stifle the disease before it begins to take hold.
Lead researcher Dr. Ashleigh Barrett-Young explains, “In the near future, it's hoped that artificial intelligence will be able to take an image of a person's retina and determine whether that person is at risk for Alzheimer's long before they begin showing symptoms, and when there is a possibility of treatment to mitigate the symptoms."
To determine if the retina could hold clues of future cognitive decline, the team analyzed data from 865 participants in the Dunedin Study, which has followed more than 1,000 Dunedin residents for 50 years to better understand human health, development, and behavior. For the Otago study, the team looked at the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) of participants at the age of 45.
They found that thicker RNFL and GCL in middle age was linked with better cognitive performance in childhood and adulthood. Those with a thinner RNFL were also more apt to experience a sharper decline in processing speed between childhood and adulthood.
The researchers say this could mean RNFL is reflective of brain health. If it is, optical scans could be a helpful tool in diagnosing cognitive decline before symptoms begin.
Dr. Barrett-Young says, "Given we haven’t been able to treat advanced Alzheimer’s, and that the global prevalence of the disease is increasing, being able to identify people in the preclinical stage, when we may still have the chance to intervene, is really important.
“In the future, these findings could result in AI being used to take a typical optical coherence tomography scan, done at an optometrist, and combine it with other health data to determine your likely risk for developing Alzheimer’s.”
She says more research is needed to see how effective this may be, but her team is hopeful. To read more about the study, click here.
