Researchers: Improving vision can help prevent dementia

The incidence of dementia is also increasing with the aging world population, and another much-anticipated Alzheimer’s drug, cranizumab, has been shown to be ineffective in clinical trials – the latest in many frustrations. Public health experts and researchers argue that now is the time to turn our attention to a different approach – focusing on a dozen or more already known risk factors, such as untreated hypertension, hearing loss and smoking, instead of overcharging. Medicine.

“It would be great if we had medicine,” said Dr Gil Livingston, a psychiatrist at University College London and chairman of the Lancet Commission on Dementia Prevention, Intervention and Care. “But they are not the only way forward.”

Emphasis on variable risk – the things we know to change – refers to “a drastic change in perception,” said Dr. Julio Rojas, a neurologist at the University of California, San Francisco. Focusing on behaviors and interventions that are already widely available and for which there is strong evidence, “we are changing the way we understand the way dementia develops,” he said.

A study of visual impairment in the United States has identified the latest variable risk factors that were recently published in Clinical Neurology. Using data from health and leisure studies, researchers estimate that about 62 percent of current dementia risk factors can be prevented and 1.8 percent – about 100,000 cases – can be prevented through healthy vision.

Although it is a fairly small percentage, it represents a relatively simple solution, said Dr. Krishna Kumar, an ophthalmologist and population health researcher at the University of Michigan and lead author of the study. Joshua Ehrlich says.

This is because eye examinations, spectacle prescriptions and cataract surgery are relatively inexpensive and accessible interventions. “Globally, 80 to 90 percent of visual impairments and blindness can be avoided through early detection and treatment, or have not yet been resolved,” says Dr. Ehrlich.

The influential Lancet Commission began to lead the movement in 2017 because of the variable risk. A panel of doctors, epidemiologists and public health experts reviewed and analyzed hundreds of high-quality studies to identify the nine risk factors responsible for most dementias around the world: high blood pressure, low levels of education, hearing impairment, smoking, obesity, depression, physical inactivity, diabetes. And low-level social communication.

In 2020, the commission added three more: excessive alcohol consumption, traumatic injuries and air pollution. The Commission calculates that 40 percent of cases of dementia worldwide can be theoretically prevented or delayed if these causes are eliminated.

“The number of people with dementia could change dramatically,” said Dr Livingston. “Even small percentages – because many people have dementia and it’s so expensive – can make a huge difference in individuals and families and the economy.”

In fact, in rich countries, “people are getting more education and smoking less, which is already happening,” he noted. Because the risk of dementia increases with age, as more people reach old age, the number of dementia diseases increases. But the proportion is declining in Europe and North America, where the incidence of dementia has dropped by 13 percent per decade in the last 25 years.

Dr. Ehrlich hopes that the Lancet Commission will add visual impairments to its list of variable risks when updating its report, and Dr. Livingston said it would be on the commission’s agenda.

Why does hearing and vision loss contribute to cognitive decline? “A neural system maintains its function through stimulation from a sensitive organ,” explained Dr. Rojas, co-author of an assistant editorial at JAMA Neurology. Without that stimulus, “neurons will die, the brain will rearrange,” he said.

Hearing and vision impairment can affect cognition by limiting the participation of older adults in physical and social activities. “You can’t see the cards, so you stop playing with friends,” said Dr. Ehrlich, “or you stop reading.”

The link between dementia and hearing loss, the single most important factor cited by the Lancet Commission as a variable risk, is well established. There is less clinical data on the association with impaired vision, but Dr. Ehrlich is a co-investigator of a study in South India to see if providing spectacles to older adults affects cognitive impairment.

Of course, this approach to reducing dementia is “desirable,” he admits: “We’re not going to get rid of low education, obesity, all of this.”

Some efforts, such as raising the level of education and treating high blood pressure, should begin in youth or middle age. Others need major policy changes; For example, it is difficult for a person to control air pollution. Changing habits and changing lifestyles – such as quitting smoking, reducing alcohol consumption and exercising regularly – are not easy.

Even fairly routine medical practice, such as measuring and monitoring high blood pressure and taking medications to control it, can be difficult for low-income patients.

Furthermore, older Americans will probably notice that routine vision and hearing care are two services that do not cover traditional Medicare.

It will pay for care related to diabetic retinopathy, glaucoma or age-related macular degeneration and it covers cataract surgery. But for more common problems that can be corrected with glasses, “traditional Medicare won’t help you much,” said David Lipschutz, associate director of the nonprofit Center for Medicare Advocacy. Or it won’t cover most hearing aids or tests, which costs a lot more.

The Medicare Advantage program, offered through private insurance, typically includes some visual and hearing benefits, “but look at the scope of coverage,” Mr. Lipschutz warned. “They could apply $ 200 or $ 300 or $ 500 for hearing aids” – but with a typical 3,000 to $ 5,000 per pair, “they might still be out of reach,” he said.

Expansion of traditional Medicare to include hearing, vision and dental benefits was part of the Beaden administration’s Build Back Better Act. But after the House passed it in November, Republican and Senator Joe Manchin III, a Democrat, rejected it in the Senate.

Nevertheless, despite the warnings and precautions, reducing the variable risk factors for dementia can pay a lot of money, and the Centers for Disease Control and Prevention has included that approach in its national plan to deal with Alzheimer’s disease.

Focusing on these factors can help reassure older Americans and their families. Some important risks for dementia are out of our control – genetics and family history and advancing age. Mutable because, however, we can work.

Dr. Livingston said, “People have dementia, your personality, the fear of losing your freedom. “The idea that you can do a lot about it is strong.”

Even delaying its launch can have a great impact. “If, instead of getting it at 80, you get it at 90, it’s a huge thing,” he said.

Eye and hearing tests, exercise, weight control, smoking cessation, blood pressure medication, diabetes care – “We’re not talking about expensive interventions or fancy surgeries or seeing specialists a few hours away,” Dr. Ehrlich added. “These are things that people can do in the communities where they live.”

Leave a Reply

Your email address will not be published.