The lowdown on treating low-vision patients

Excerpted from page 50 of the October 2015 edition of AOA Focus.

Even the youngest baby boomers are now at risk for age-related eye disease and low vision. But doctors of optometry have a message they can share with this demographic of patients, and others: Technological advances continue to help visually impaired patients improve their quality of life.

For instance, in October 2014, the U.S. Food and Drug Administration approved a miniature telescope—a surgically implanted prosthetic for patients with later-stage age-related macular degeneration (AMD). It is implanted in the worse-seeing eye, which then sees a magnified image, while the other eye sees the regular image through glasses.

"It's something that doctors can talk to their patients about as an option, but there need to be careful evaluations to see if the patients qualify," says Rebecca Marinoff, O.D., assistant clinical professor and supervisor for the Low Vision Residency Program at the State University of New York College of Optometry. Not every patient can tolerate the difference between the two eyes.

In addition, vision rehabilitation tools, such as closed-circuit televisions (CCTV) have improved in recent years. CCTVs now include high-definition monitors and cameras, plus optical character recognition capabilities. Likewise, zoom and freeze-frame capabilities on smartphones and tablets can aid visually impaired patients.

Even with such improvements, though, doctors shouldn't forget about updated standard devices, says Susan Primo, O.D., director of vision and optical services at Emory Eye Center. "Handheld or stand magnifiers, telescopes, prisms and other traditional tools still have tremendous value in helping visually impaired patients and are often quite affordable."

Rehabilitation methods also remain critical for low-vision patients. For example, doctors "can determine the preferred retinal locus (PRL) for eccentric viewing through formal microperimetry or other central visual field testing techniques," Dr. Primo says.

"Virtually all patients with central vision loss, especially from AMD, will utilize a PRL. The better we can help them consciously locate it, the better they will function overall."

Low-vision patients with peripheral vision loss tend to be more challenging to treat. "Some of these patients can be fit with prisms to help them be more aware of the side vision that's missing," Dr. Marinoff says. A referral to an occupational therapist for mobility training likely will be appropriate—an important reminder that visual rehabilitation is often a team effort.

Dr. Marinoff's tips:

• Educate low-vision patients that there are a range of devices that can help them, not just one silver bullet.
• Depending on a state's driving laws and the patient's vision, a bioptic telescope may help certain patients continue to drive safely.
• Remember that exam results don't tell doctors everything, so ask about daily activities. A patient with 20/50 vision could be experiencing low vision due to reduced contrast.

Dr. Primo's tips:

• Help patients focus on specific goals, such as reading the newspaper or watching television, and then perform your evaluation based on these goals.
• Some patients' visual impairment will be too profound for one practitioner to handle. They may require comprehensive rehabilitation and training from a larger team.
• Prisms and other innovative training can help stroke victims, for example, with hemianopic field loss regain some visual function.