Published: Feb. 15, 2012
Updated: Feb. 15, 2012
Her grandmother had been a college professor, a world traveler, and a pilot. But vision loss made it impossible for her to even drive a car. On top of that, she began to develop cognitive impairment.
“Vision impairment and memory impairment are a really bad combination,” Whitson says.
“My grandmother had a little watch that would tell the time out loud. But she was always misplacing it. If you can’t see where you put something, and you can’t remember where you put it, then you’re in bad shape.”
All the things that your eyesight enables you to do -- read, work a crossword, fix a lawnmower engine -- also feed your brain.
So it’s not that surprising that people with macular degeneration, the most common cause of age-related vision loss, have greater rates of cognitive impairment than people of the same age who have normal vision.
Whitson, now a Duke ophthalmologist, and other scientists at the Duke Eye Center have published some of the most detailed data available documenting that fact, and now they’ve designed a low-vision rehab program especially for people with cognitive impairment.
Whitson has always been interested in how seemingly unrelated conditions -- for instance, depression and bone fracture risk -- can work together to worsen an older person’s ability to function.
Her grandmother’s diagnosis in 2005 made her think about the link between macular degeneration and cognitive impairment, and she discovered that other scientists had found that the two conditions occurred together more often than would be expected just by chance.
About that time, Duke ophthalmologist Scott Cousins, MD, gave a talk on the topic, and Whitson approached him about studying the link.
That was six years ago. Now Whitson, Cousins, and Diane Whitaker, OD, have a study in press in the Journal of the American Geriatrics Society that documents in great detail how the usual services offered to patients with low vision fail to meet the needs of patients with other problems, including cognitive impairment.
The researchers conducted more than 600 interviews with 98 patients with macular degeneration and their companions who accompanied them to low-vision training. In most cases, they interviewed each patient and their companion multiple times. The researchers also performed cognitive and vision tests with the patients.
“The study categorizes some of the ways that comorbid medical problems impact a patient’s ability to benefit from a health service such as a low-vision training program,” Whitson says.
Whitson and Whitaker have used what they learned to design a low-vision rehabilitation program especially for patients with cognitive impairment. The program differs from the norm in several ways.
For one, it includes more repetition. “Even people with short-term memory problems can master something new, but they need to hear it multiple times, over a short period of time, to reinforce it,” Whitson says.
The new program is very focused -- the participants try to achieve just two goals during a six-week training period. “We try to hammer in those two lessons, rather than having a big agenda,” Whitson says. The participants set their own goals, such as being able to read a bible or fix a lawnmower carburetor.
Eliminating distractions helps too. The Eye Center’s usual training room for people with low vision is so full of nifty gadgets that the doctors call it “the toy shop.” But it can be overwhelming, so the specially designed training happens in a room with little more than a chair, a desk, and the closed-circuit television device often used for viewing magnified objects.
The last essential element of the training is a companion -- a friend or family member who attends one of the six training sessions and helps the patient with homework for one hour each week. The team’s study suggested that many patients need someone to act as an advocate at their appointments and to help them remember what they learn at training.
The team just completed a pilot study of the new program, which revealed something surprising; after the low-vision intervention, many of the patients not only were better at performing vision-dependent study tasks, but also showed an improvement in memory scores. “If you are learning a new skill, that’s a cognitive intervention as well,” Whitson says.
Whitson and Whitaker have now begun a new project to track success in a small number of patients using a novel tool they developed.
The usual way of evaluating progress involves the patient answering questions about how much they’ve improved at important tasks such as grocery shopping or driving. But such self reports may be unreliable, particularly in subjects with cognitive problems.
So Whitson and Whitaker developed a second measure of success by timing the participants as they actually perform tasks, such as writing out a grocery list. That yields a concrete measure of progress, such as what the grocery list looks like before the training and after.
The team is now exploring some of the reasons behind the link between macular degeneration and cognitive impairment. They’re recruiting patients with macular degeneration for a study that will use functional MRI to track how these patients’ brain function differs from people of the same age without macular degeneration.
“The Eye Center is embracing a whole-person approach,” Whitson says. “As Dr. Cousins says, we must ‘think outside the eye’ if we’re going to continue to provide the best care available, especially for an aging population.”
This work was funded by the Hartford Foundation and the National Institutes of Health.