Originally published October 20, 2014. To see more, visit NPR.
(Photos: Courtesy of David Myung and Dr. Suman Thapa/University of Iowa)
Getting an eye exam typically involves big complicated machines. But eye doctors are trying to get the big and complicated out of the equation by using smartphones and tablets instead. That way, they figure, eye exams can be done just about anywhere — even a village in Nepal.
That’s where Dr. Chris Johnson and his colleagues are using iPads to test people for glaucoma, a disease that often has no symptoms until it has irreversibly damaged eyesight. That’s because it nibbles away at vision at the periphery of the visual field.
Finding that out usually involves sitting in front of a big machine and staring at a screen while gray dots appear and disappear.
Instead, Johnson tested an off-the-shelf free app called Visual Fields Easy to screen about 200 patients in Nepal. “I was skeptical at first; we did some tests and calibrated it.”
The app was very good at identifying people with moderate to severe disease, less so at screening out people with normal vision. “It works much better than I expected,” Johnson, who specializes in developing diagnostic tests, told Shots. He and his colleagues are now expanding the tests to India, with the aim of refining it. “I know I can make it better.”
Johnson presented his data Monday at the meeting of the American Academy of Ophthalmology in Chicago, and he was far from the only one tinkering with mobile tech. A number of researchers presented devices that clip onto iPhones to turn them into diagnostic tools.
Dr. David Myung, chief resident at Stanford University Hospital, wanted to come up with an easy way to photograph an eye inside and out. A big ophthalmology practice would have a machine that does that beautifully, but it costs tens of thousands of dollars and requires specialized training. Myung wanted something that a harried ER doctor or nurse could use on the fly.
“We wanted to find a low-tech way to do it,” Myung told Shots. So he and his colleagues came up with a plastic arm that snaps onto an iPhone, holding an ophthalmology lens in front of the camera at just the right distance. “The plastic arm is about as low-cost as it gets.”
To get around the fact that the photographer isn’t an ophthalmologist, it’s designed so that people take videos or multiple photos. “It’s a little like trying to take pictures of your kids, and they’re moving around all the time. If you take 10 or 15 photos, one of them going to be in focus.”
The gizmo is also being tested to see if it can reliably screen people at a public hospital for diabetic retinopathy, and Myung and colleagues are applying for FDA approval, since it’s a medical device. “We originally developed this for ophthalmology work in developing countries,” Myung says. “People do have smartphones and digital capability. We think it could be very useful there.”
And maybe closer to home, too.
Since the goal is cheap, simple tests using available technology, couldn’t I just do my eye exam at home skip the two hours sitting in the waiting room with my eyes dilated? There are plenty of eye tests apps ready for download right now. But it’s complicated, Johnson says.
“Did they get a bad result because they didn’t do the test right, or is there a change in their visual status?” Johnson says. He’s worried that people will skip an eye exam, then get frightened by a false negative result to a home test. “I think having that as a screen that’s available for people who don’t have good access to health care is the first thing. Home testing will require some additional things to make it bulletproof.”
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