A Device to Combat Peripheral Vision Loss
A wearable device that warns of collisions that could cause falls may make walking safer for people who have lost some of their peripheral vision, researchers say.
Patients with conditions including retinitis pigmentosa, glaucoma, or brain injury that causes half visual field loss, are often at increased risk of collision with “high-level obstacles” that can cause falls.
But now researchers from Massachusetts Eye and Ear, Schepens Eye Research Institute, have evaluated a device they developed for patients with this kind of vision loss. To analyze its effectiveness, they used an obstacle course .
Their findings are featured on Investigative Ophthalmology and Visual Science (IOVS).
“We developed this pocket-sized collision warning device, which can predict impending collisions based on time to collision rather than proximity. It gives warnings only when the users approach to obstacles, not when users stand close to objects and not when moving objects just pass by. So the auditory collision warnings given by the device are simple and intuitively understandable,” said senior author Gang Luo, Ph.D., Associate Scientist at Mass. Eye and Ear/Schepens, and Assistant Professor of Ophthalmology at Harvard Medical School.
“We tested the device in a density obstacle course to evaluate its effect on collision avoidance in people with peripheral vision loss. To show its beneficial effect, we compared the patients’ mobility performance with the device and without it. Just demonstrating the device can give warning for obstacles in walking would not prove the device is useful. We have to compare with a baseline, which is walking without the device in this case.”
According to a news release from Massachusetts Eye and Ear, twenty-five patients with tunnel vision or hemianopia completed the obstacle course study and the number of collisions and walking speed were measured.
Compared to walking without the device, collisions were reduced significantly by about 37% with the device and walking speed barely changed, the news release said. No patient had more collisions when using the device than when not using it.
“We are excited about the device’s potential value for helping visually impaired and completely blind people walk around safely. Our next job is to test its usefulness in patients’ daily lives in a clinical trial study,” Luo said.