A new French study reveals a possible link between near-vision problems and dementia risk in patients over 65. Eye care doctors around the world are now suggesting that older patients take their eye symptoms seriously and don't just write off near-vision problems as an inevitable sign of aging.
This so-called "Three City" study took place in the French cities of Dijon, Bordeaux, and Montpellier. Around 9,294 people over the age of 65 participated in this longitudinal analysis that lasted from 1999 to 2001. People involved in this study conducted follow-up exams every two years to check the participants' vision and mental health.
Analysts took all of this data, which was compiled in the 4th edition of Diagnostic and Statistical Manual of Mental Disorders, and looked at 7,736 patients with vision data at baseline. Of these patients, 5.3 percent reported distance-vision problems, 8.7 percent had mild near-vision problems, and 4.2 percent had moderate or severe near-vision loss.
Researchers found that people with moderate to severe near-vision problems had an increased risk of developing dementia over a 12-year period. However, there was no direct correlation between dementia risk and distance-vision issues.
Specifically, analysts noted that of the 882 dementia patients in their study, 17.1 percent had mild near-vision loss, and 21.2 percent had moderate to severe near-vision loss. By contrast, 10.2 percent had no vision loss and 18.6 percent had distance-vision loss.
The data also suggested that dementia patients tended to be in their mid to late 70s, with 76.9 being the average age of a dementia patient. Also, women and people with hypertension were far more likely to develop dementia.
Virgine Nael, a PhD student at the University of Bordeaux, was the head researcher on this project. She told reporters that the main finding from this study is that "clinicians need to be careful of eye vision and realize its importance for these patients." She also advised all people 65 and over to seek clinical examination to test for both dementia and vision problems.
Nael said she and her team became interested in this issue after reading through two major studies looking into the link between vision and Alzheimer's disease. One 8-year study showed that patients with great vision had a decreased risk of dementia. Another case-control study suggested that people with near-vision problems had a higher risk of developing dementia.
Nael's team assessed each patient's near-vision using various reading tests 33 cm away from their eyes. People who scored between 20/30 and 20/60 were defined as having "mild" visual issues, whereas people with scores of 20/60 were classified as either moderate or severe.
To test for distance-vision problems, doctors asked patients if they could distinguish a well-known face from 4 meters away. Those that couldn't recognize the face were classified as having distance-vision issues.
Nael presented her research at the 2017 International Conference on Alzheimer's and Parkinson's Diseases and Related Neurological Disorders. This conference was held in Vienna's Austria Centre in the Kaisermühlen district from March 29th to April 2nd.