Virtual Reality Gives Clinicians a Window on Glaucoma Patients' Deficits

By Linda Carroll

March 23, 2020

(Reuters Health) - Virtual reality simulations can provide eye care professionals with a window on the kinds of deficits glaucoma patients experience in daily life, a new study suggests.

In an experiment, nearly 100 glaucoma patients participated in five virtual reality simulations of everyday tasks, including shopping, using stairs at night, and navigating around a city at night. Compared to 50 healthy controls, glaucoma patients showed more disability in performing everyday tasks in nighttime simulations, particularly navigating stairs or a cityscape, according to the results published in JAMA Ophthalmology.

Fifty-eight patients (59.1%) had vision-related disability in at least one simulated daily task, the authors found.

"Virtual reality has empowered eye care professionals to discern the patterns and the forms of disability that patients with visual impairment may encounter in their real-life activities," said coauthor Dr. Christopher Leung of The Chinese University of Hong Kong.

"It provides a powerful educational tool for glaucoma patients to better understand how visual field defects may translate to disability in daily living and facilitates eye care professionals to administer visual rehabilitation," Leung said in an email.

Leung said the impact of low light on disability was most striking. "Whereas only 8% of glaucoma patients had vision-related disability in city navigation simulated in daytime, 31% had vision-related disability in the same navigation simulated in nighttime," he said. "Clinicians often do not fully appreciate from the patients' perspective how glaucoma impairs daily function because many glaucoma patients have really good central vision with a normal visual acuity test result."

Leung and his colleagues recruited 98 patients and 50 controls to participate in each of five virtual reality simulations: identifying 10 shopping items from a supermarket rack; walking up and down two flights of stairs in daylight; traversing the same sets of stairs at night; navigating a city area over a virtual distance of approximately 90 m in daylight; and navigating the same city area at night.

Vision-related disability scores were calculated based on time required to complete the simulation, number of items incorrectly identified and number of collisions.

Performance by glaucoma patients was not very different from controls during daytime simulations, but during nighttime simulations, they took 92.8 seconds (95%) longer than the healthy controls. And for each decibel decrease in binocular visual field sensitivity, the risk of a collision increased by 15% in the nighttime stair and city simulations.

A better understanding of glaucoma patients' disabilities would help eye care professionals devise better treatments, Leung said. "We are collecting clinical data to evaluate how training patients with visual impairment through VR simulations may help prevent falls or collisions."

The new study shows the value of assessing glaucoma-caused disabilities with virtual reality, said Dr. Louis Pasquale, chair of ophthalmology at The Mount Sinai Hospital in New York City.

"When we examine patients, we are creating a very artificial world with high contrast and in which we examine each eye separately," said Pasquale, who was not involved in the new research. "That doesn't tell us how their vision problems translate into a real-world environment."

Pasquale isn't convinced the method will translate from the lab to the clinic, but he applauded the researchers on devising a valuable research tool.

"They've done a remarkable job documenting the disabilities associated with glaucoma," he said. "For example, glaucoma patients have more difficulty seeing at night. I have found that when it gets to wintertime, glaucoma patients tend not to want appointments after 3 p.m. They are self-regulating."

Prior survey-based research has found that patients recognize they have problems driving at night, Pasquale said. "But this is the first paper to really demonstrate the functional disability our glaucoma patients are experiencing," he said.

The research may also help those involved in visual rehabilitation services, Pasquale said. "They would be well informed by reading papers such as this," he said. "It's very helpful when you can really spell out exactly what's happening in the real world where patients have trouble driving at night and have problems reading menus in dimly lit restaurants."

SOURCE: and JAMA Ophthalmology, online March 19, 2020.