Could Treating Vision Loss Help Older Adults Live Longer?
Research finds cataract surgery is associated with lower mortality – though it’s not clear why.
More than 20 million people age 40 and older in the U.S. have cataracts, according to the Centers of Disease Control and Prevention. The condition, which grows increasingly common with age, involves a clouding of the eye’s natural lens, and experts say what’s clear is that resulting vision problems can have a significant – and often not fully appreciated – impact on a person’s life.
In most cases, age-related cataracts tend to develop gradually and, as with hearing loss, which also tends to develop over time, progressive vision issues can impact one’s ability to stay connected with others. Where once a person might just have driven to see a friend, that individual may now be more hesitant to drive – particularly at night – because of vision problems. “You have too much glare or you can’t see very well, and so you stop driving as much as you used to,” says Dr. Anne Coleman, a professor of epidemiology at the UCLA Fielding School of Public Health and professor of ophthalmology at the university’s Stein Eye Institute. “You go to events and you really can’t see people, you can’t see your way around the room.”
Experts say such effects can be socially isolating and spiderweb through many other facets of a person’s life.
Sharon Christ, an associate professor of human development and family studies at Purdue University, and fellow researchers have found the loss of visual acuity – or clarity or sharpness of vision – can negatively affect the functional status of older adults. Namely, their ability to do what are referred to as instrumental activities of daily living declines; “activities like cleaning, being able to cook – some of them are a little more social in nature, like being able to use the telephone,” Christ notes. These serve as a measure of one’s ability to live independently.
Research she led published in 2014 in the journal JAMA Ophthalmology found that loss of visual acuity adversely affected IADL, which subsequently increased a person’s risk of dying. “Starting out with lower vision and also if your vision is declining quicker as you age, that tends to lead to an increase in mortality,” Christ says.
Conversely, the benefits of treating visual problems may extend way beyond simply improving one’s vision.
Research finds undergoing cataract surgery to correct the issue is associated with a lower rate of death for all causes. One recent study of 74,044 participants in the Women’s Health Initiative clinical trial found “cataract surgery was associated with decreased risk for all-cause mortality and mortality attributed to vascular, cancer-related, accidental, neurologic, pulmonary, and infectious causes.” The overall, or all-cause, mortality rate was 1.52 deaths per 100 person-years (a measure that takes into account the number of persons studied and the time they were observed) in the cataract surgery group and 2.56 deaths per 100 person-years in the cataract diagnosis group, who didn’t undergo surgery.
But as noted by researchers – including Coleman, the study’s senior author – the research published online in JAMA Ophthalmology in October did not explore why this link exists. Further study is needed to understand the reasons for the association.
“Cataract surgery is done to improve people’s vision,” Coleman says. “So what is it about improving your vision that improves the quality of life, but also decreases your risk of dying?” A person may be more comfortable exercising, for example, as a result of improved vision: “You’re not as afraid of falling, because your depth perception is better,” she says. And it could help in other ways, like managing medications – including distinguishing between individual pills. “Maybe the shape is different and that helps,” Coleman says. “But a lot of times the colors can be hard to discern, and so it helps being able to see it more clearly and not mix up your medicines.”
At the moment, though, it remains unclear what explains the association between cataract surgery and a decreased risk of death. “It’s really speculation at this point,” says Dr. J. Bradley Randleman, a professor of ophthalmology at the University of Southern California, and director of cornea, external disease and refractive surgery at the USC Roski Eye Institute. “Because we have the information that these risks are lower, and we need to find a reason why.” Nor is there an established, delineated cause-and-effect relationship. Why, for example, might cataract surgery be associated with things like a lower rate of cancer deaths? “Things that are hard to directly relate to the cataract surgery,” Randleman says. “The data looks wonderful, but it really induces as many questions as answers.”
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Taking in the broader view, experts say what is apparent is that significant declines in vision which go unrecognized or unaddressed commonly have consequences extending well beyond what a person can see – whether undermining quality of life, raising safety concerns (like increased risk of falls or car accidents) or preventing healthy behaviors like exercising.
“The fact that you have some cataract development doesn’t absolutely mean you have to have surgery right away. Some people – the first thing that this does is changes their glasses’ prescription,” Randleman says. On the other hand, simply putting off addressing the issue isn’t exactly a winning strategy either.
Source: US Health News