Eyes and aging - anisometropia 3D vision, binocular vision and increased fall risk

A new study published in the journal, Optometry & Vision Science, has confirmed what many eye doctors with elderly patients already know: changes in the eyes as we age can degrade our ability to see depth (stereopsis) and in three dimensions (3D vision). That can contribute to blurry vision, eye strain and eye fatigue, and an increased risk of falls. Falls in the elderly are troubling because they can be the cause of brain injuries, broken bones or worse.

The new study looked at the incidence of a condition called anisometropia in elderly patients. Anisometropia is a condition in which the two eyes have unequal refractive power. That means that the focusing ability of the two eyes is unequal. Each eye is in a different state of myopia (nearsightedness) and hyperopia (farsightedness). The condition is characterized by blurry vision, double visoin, eye strain, eye fatigue, loss of depth perception. When anisometropia happens in children and infants, it can impair the development of normal binocular vision, which can lead to many learning and other problems.

Anisometropia is common in elderly people and it grows exponentially with age. The study found that significant anisometropia is at least 10 times more common in those older than 75 years than it is in children.  This is an alarming statistic and must be taken seriously by eye doctors.  At our Vancouver optometry clinic, we see large number of elderly patients because of our low vision practice and so we are always on the look-out for anisometropia.

The study's authors pointed out that the prevalence of anisometropia in US children is between 2 and 4% whereas data for those near 80 years old shows that 32% have 1.00 D or more anisometropia.

Related article:

When seniors loose depth perception and need to see a developmental optometrist
Thursday, June 28, 2012

Source:

Longitudinal Increase in Anisometropia in Older Adults

Haegerstrom-Portnoy, Gunilla; Schneck, Marilyn E.; Lott, Lori A
Optometry & Vision Science:
January 2014 - Volume 91 - Issue 1 - p 60-67

In women, future dementia shows up in the eyes first - maybe early enough to do something about it

April is women's eye health and safety month.  That makes the results of a new study  reported in the March 14, 2012, online issue of Neurology timely because the results have important implications for women over age 65.


Retinopathy, a disease of the blood vessels in the retina (which as at the back of the eye) was found to be an important marker for the later development of dementia in women who are 65 and older. Even mild retinopathy in women in this age group could be a marker of cognitive decline and related vascular changes in the brain, according to the study.


Retinopathy is usually caused by Type II diabetes or hypertension.


The study's results suggest that retinopathy may be useful as a clinical tool if it can be shown to be an early marker related to neurologic outcomes. If retinopathy is detected early enough, there may be room for the patient to make lifestyle changes or participate in medical interventions that can slow the onset of cognitive decline.  As with many diseases, early diagnosis and treatment can make a big difference in quality of life.



It seems that brain health is in the eye of the beholder.  The study is an other example of why eye exams by an optometrist (which routinely include an examination of the blood vessels in the retina) are one of the best things you can do for your overall health.  Not only can they detect markers of future cognitive decline, eye exams can diagnose, diabetes, hypertension, multiple sclerosis, cancer and other diseases that show up first int he eyes.  In fact, eye exams are often the first to detect chronic diseases.

While the study discussed above involves changes in the physiology of the eye as an early marker of cognitive decline, other studies have shown a connection between uncorrected visual impairments and cognitive decline.  The latter studies seem to indicate that older people who lack proper visual stimulation are more prone to cognitive diseases like Alzheimer's and dementia.  Increasingly, science is making the link between vision and eye health on the one hand and brain health on the other.  That's why it's important to see the optometrists regularly as we age.

Sharp Vision Sharp Mind

Poor vision and inadequate eye health care is linked to cognitive decline in elderly people.

In a recent study of 625 elderly patients conducted by the University of Michigan, those with poor vision who did not receive proper eye care were a stunning nine times more at risk of developing Alzheimer's disease and five times more at risk for some form of cognitive impairment. 

In contrast, those with good vision had a 63% reduced risk of developing dementia.

Another study that reached similar results was published in the journal Optometry & Vision Science in December 2010.  In the latter study, the researchers simulated visual impairment in a group of elderly people.  They found that visual impairment can lead to a slowing of cognitive performance in older adults.  Cognitive impairment was greater in older adults that it was in their younger counterparts. 

The findings of these studies have important implications for older people who have a high prevalence of cataracts or may be prone to ignoring their health. They may be well advised to have surgery to remove their cataracts in order to prevent any possible cognitive decline and to always keep current with their spectacles prescription.

Sharp vision and a sharp mind seem to go hand-in-hand.  Protect both by scheduling a comprehensive eye health examination.  Remember, age is a risk factor for a host of diseases that can lead to vision loss. Glaucoma and age-related macular degeneration are two of the most prevalent.  An eye exam is the only way to catch these diseases early enough to do something about them.