New Tools Could Help Glaucoma Patients Explain Their Vision Loss

By Carolyn Crist

December 15, 2020

NEW YORK (Reuters Health) - New tools, such as an app for tablets or smartphones, can help glaucoma patients, their doctors and their family members to better understand their vision loss, according to a group of ophthalmologists.

With a better understanding of the patient's view, doctors can gain insight into the real-world effects of vision loss and create more nuanced rehabilitative programs, the team writes in the British Journal of Ophthalmology.

"Vision loss from glaucoma is, unfortunately, irreversible and has serious consequences for driving and increased falls," said senior author Dr. Deepta Ghate of the Stanley M. Truhlsen Eye Institute at the University of Nebraska Medical Center in Omaha.

Glaucoma affects about 2% of people in the U.S. sover age 40, according to the National Eye Institute. More than half of patients have at least moderate vision loss by the time they're diagnosed, typically because it begins on the periphery of the visual field where the brain fills in the gaps.

Current clinical tests for glaucoma focus on intraocular pressure and optic-nerve damage, but they don't assess patients' perceptions of their own vision loss, the authors write.

"Patients who do not understand their vision loss tend to refuse rehabilitation therapy and are less motivated to comply with their treatment and follow-up visits," she told Reuters Health by email. "Family members also seldom understand how disabling the vision loss can be."

Dr. Ghate and colleagues created an iPad app for glaucoma patients to self-characterize their visual perceptions with the right eye, left eye and then both eyes. The patients focused on a large poster of a busy street scene on the wall and then modified the same image on the iPad app with "blur" or "contrast" settings to match their view.

The research team then analyzed the app responses, which provided a grid format that corresponded to specific points on a typical clinical visual field test.

All 12 patients reported some degree of "blur." Oftentimes, this blur appeared at the upper and inner peripheries for each eye, where vision overlaps. Importantly, no patients reported a "dim" or "black" spot, which could change how doctors perceive their patients' vision loss and recommend treatment.

"I treat glaucoma every day, and I was stunned to understand for the first time exactly what my patients 'see' every single day," Dr. Ghate said. "I was also surprised at how emotional some of our patients and their family members became after they did the iPad test and pictorialized their vision."

The study has several limitations, including a small sample size and focusing only on patients with good central vision and cognition. Patients with advanced cognitive impairment and loss of their central vision may face difficulties when using the app, the authors note.

Future studies could use an eye tracker to monitor where patients look while modifying the image on the app, and additional app settings could track changes in color or other visual impairments. In addition, researchers should monitor their patients' awareness of vision loss and any difficult emotions that may arise, the team suggests.

"These are people who have lived with their vision loss from glaucoma for decades, but having a picture of how they see the world to show to their family rather than the black and white of the clinic-based visual field made them realize exactly how much vision they had lost over the years," she said.

Beyond technology, eye specialists should continue to try to understand their patients' point of view by asking specific questions about their vision concerns and listening intently, said Dr. George Spaeth of Wills Eye Hospital in Philadelphia. Dr. Spaeth, who wasn't involved in this study, has written about the need for a patient-focused view when treating glaucoma.

"For a long time, doctors have told patients what they see and don't see, but they often do a poor job of helping patients describe what is troubling them," he told Reuters Health by phone. "We should treat patients based on what they feel and see and what their symptoms are."

SOURCE: British Journal of Ophthalmology, online November 20, 2020.