Can an eye exam reveal Alzheimer’s risk?

Looking for clues about the health of your brain? You might want to pay a visit to your eye doctor. Research increasingly links common eye conditions — glaucoma, age-related macular degeneration, and diabetic retinopathy — to risk for Alzheimer’s and other forms of dementia.

What’s interesting about the study results, says Dr. Albert Hofman, chair of epidemiology at the Harvard T.H. Chan School of Public Health, is that cataracts, another common age-related eye condition, had no apparent connection to dementia risk. This gives scientists an important clue about the cause of dementia and Alzheimer’s disease, he says.

“My view, and one of the possible explanations that the authors present, is that these three eye diseases and Alzheimer’s and dementia have a joined etiology” — that is, a common causative factor. “All are linked to cardiovascular disease,” says Dr. Hofman.

How are eye conditions linked with cardiovascular disease?

  • Glaucoma is a condition marked by increased pressure in the eye that can lead to vision loss. It has been linked to high blood pressure, diabetes, and poor blood circulation.
  • Age-related macular degeneration involves breakdown of the macula, the part of the retina responsible for sharp central vision. It has also been linked to heart disease.
  • Diabetic retinopathy occurs in people with diabetes when high levels of blood sugar damage blood vessels in the retina. There are strong links between diabetes and cardiovascular problems.

Cataracts — clouding of the lenses of the eyes — are more likely to develop as people age. However, they don’t appear to increase the risk of cardiovascular disease, Alzheimer’s disease, or other types of dementia.

Eyes on Alzheimer’s

The Adult Changes in Thought study, which began in 1994, included 5,400 dementia-free adults. Participants were followed until they decided to leave the study, died, or developed dementia. Research published in Alzheimer’s & Dementia in 2019 analyzed data drawn from the Adult Changes in Thought study. This time, the researchers focused on 3,800 of those participants, both with and without eye disease at the start of the study. Some 792 of them went on to develop dementia.

Study authors found that people with age-related macular degeneration were 20% more likely to develop dementia compared with people who did not have the eye disease. People with diabetic retinopathy were 44% more likely to develop dementia than those without. People in the study with a recent glaucoma diagnosis — but not participants with established disease — had a 44% higher rate of dementia. It’s not clear why there was a difference between people with new or existing disease.

Can eye exams be used to predict — and better still, prevent — Alzheimer’s?

While these findings show a link between three eye diseases and brain risks, one important question remains: what does this information mean for you? Can an eye exam tell you if you are destined to develop dementia in the future? More importantly, can it help you prevent it?

Someday the answer to those questions may be yes. For now, however, eye exams are valuable in detecting eye disease early so it can be treated — but they can’t yet yield much predictive information about your brain’s future health, says Dr. Hofman.

But there are lessons we can take from the study when it comes to avoiding Alzheimer’s disease. Today the only known way to prevent Alzheimer’s and other forms of dementia is to prevent cardiovascular disease.

“Doing all the things that you would do to prevent heart attack and stroke are likely beneficial to prevent Alzheimer’s disease,” says Dr. Hofman. This means treating high blood pressure and cholesterol, eating a healthy diet, getting enough sleep, and maintaining a regular exercise program.

If you have a family history of cardiovascular disease or a history of cardiovascular-related eye diseases, you may want to be even more aggressive in controlling your personal risk factors, says Dr. Hofman.

Comments:

  1. Kimberly Clarkin

    When referring to Glaucoma are the studies based on open angel and/or closed angel?

  2. Richard Adrian Harvey MD

    I am 75 years old and was just diagnosed with Age Related Macular Degeneration (AMD). I am very fit for my age, have an excellent lipid profile, normal blood pressure, normal weight and no evidence of coronary artery disease. My diet rarely includes meat. I was started on PreserVision (Areds 2 formula) and advised to wear dark glasses which I have done for many years. In the study that links AMD to Alzheimer’s disease are there subgroups that showed less or no association ? If the 2 diseases are linked might PreserVision slow the progression of Alzheimer’s disease ?

  3. Maggie Owens Yates

    Approximately 14 years ago I wondered about an Alz. and Gla. link. My Glaucoma doctor swore there was no connection. I am 68 and was diagnosed with glaucoma in my forties. Currently have severe advanced glaucoma with left eye blindness. Vision is significantly better in R eye. (20/25)
    I have significant inflammation in R eye. Retina specialist does not recommend surgery due to Gla. I think I should explore what the inflammation signifies in light of this study. Thank you for providing this information.

  4. Kathleen G.

    I also meant to say there are quite a few different types of glaucoma – are they all equally strongly connected to dementia?

  5. Kathleen G.

    I don’t see any mention whatsoever regarding whether these links were found with equal frequency among people whose diabetes or glaucoma were under good medical control or not. That’s very important information and it varies widely.

  6. Catherine Thomas

    My mother now has dementia and has had glaucoma for twenty years. She has been taking a lot of drops for her eyes all this time and I have often wondered if the chemicals in the eyedrops, could lead to dementia. I believe those with macular degeneration take some of the same drops. Any word on this? Bromodidine, Dorzalimide, Latanoprost and Restasis are the names of the drops.

    • Robert Dors

      Restasis was a medication initially developed as an anti-rejection drug but is now used to treat dry eye as it lessens the inflammatory component of dry eye and stimulates tear production. Latanoprost, dorzolamide and I believe it is brimonidine your referring to all are used to treat glaucoma by reducing pressures. None of these have been show to contribute to Alzheimer’s disease. At one time brimonidine was even thought to protect nerves from from damage and has been researched as a treatment for Alzheimer’s as well but its nerve protection properties appear to be so small that this is no determined to be effective. None of these 4 medications are used to treat macular degeneration. Currently no drops exist that are approved for macular degeneration treatment in North America. The death of brain cells in Alzheimers and the death of vision cells in glaucoma is essentially the same process and these diseases are highly linked. Retinal scans are currently able to see the Alzheimers plagues in patients long before other forms of imaging identify them in the brain.

    • katherine kopec

      interesting..I have no high blood pressure – no diabetes – no heart disease.
      my weight is good. I work out daily –
      yet I was diagnosed with glaucoma 3 years ago. I am 75 years old and am now very concerned..my mother passed away from alzheimer disease.
      Hopefully, soon there will be a cure for glaucoma..one has to wonder about the necessary drops..as possibly trouble for the brain or the lungs.

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