NEW YORK (CBSNewYork) — Could a quick eye test be a way to diagnose Alzheimer’s disease?

That’s what a new study has found.

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As CBS2’s Dr. Max Gomez reported Monday, researchers are hoping for earlier and easier diagnosis of the disease.

All of proposed early diagnostic methods for Alzheimer’s have been pretty invasive or expensive — spinal taps, brain scans, blood tests and neurocognitive exams.

The eye test could be a much easier test and allow doctors to start treatment earlier when it might be able to slow the disease.

Ninety-seven-year-old Scott Hughes and her identical twin sister, Virginia, were always close. When Virginia started having trouble with her memory and thinking, Scott knew something wasn’t right. Virginia was later diagnosed with Alzheimer’s disease.

“It was heartbreaking because she was so outgoing and loving. She wasn’t going to be who she had been before, and that is tragic to see in a person you love,” Scott said.

With one twin having Alzheimer’s and the other healthy, researchers at Duke Eye Center studying the link between eye and brain health thought the sisters were a good case to examine. They took images of their eyes and discovered the twin with Alzheimer’s disease had significantly decreased blood vessel density in the retina. That finding spurred a new study of more than 200 people.

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“Cognitively healthy normal individuals do not have these changes in their retina,” Dr. Sharon Fekrat said.

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Fekrat, the study’s lead researcher, said the eyes may be a window to our brain health.

“These changes happening in the retina of the eye may actually mirror the blood vessel changes happening in the brain of individual’s with Alzheimer’s disease,” Fekrat said.

Virginia passed away 14 months ago.

“Every night after dinner we had a conversation. Sometimes she would be able to respond and sometimes she wouldn’t, but she always knew that sister was calling,” Scott said.

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This eye finding is an important first step. Researchers can know when the eye changes start and whether they might be an early warning sign of Alzheimer’s. That would allow doctors to test drugs much earlier in the disease course, when the medications have a better chance of slowing or stopping the brain deterioration.