To an outsider, the numbers may be surprising: About 167,000 veterans are legally blind, and about 285,000 have glaucoma, a disorder in which increasing fluid pressure inside the eye causes the gradual loss of sight. Overall, the VA estimates that as many as 1.5 million veterans live with vision impairments that interfere with everyday functioning.
The VA’s vision loss research program seeks to answer questions about how best to meet the needs of these veterans: to help improve vision by repairing or replacing damaged organs and tissues; to restore function to those living with vision loss; and, when possible, to prevent vision loss before it occurs.
Because so little is known about how visual injury can occur to an eye that has suffered no overt damage, VA’s Office of Research and Development funds biomedical and clinical studies aimed at unraveling the connections between injury and vision loss.
For the vast majority of veterans who suffer vision loss, little can be done to reverse or treat damage once it has occurred. Many VA researchers focus on the delivery of vision care itself – how it can best be administered to optimize outcomes and help patients make the most of their remaining sight. Dr. Joan Stelmack, who was named 2014’s VA Optometrist of the Year by the Armed Forces Optometric Society, has been a VA clinician and researcher for 31 years, currently at the Edward Hines, Jr. VA Hospital in Hines, Illinois. Her work focuses on veterans with low vision: a term used to refer to visual impairment that’s not correctable with medicine, surgery, or glasses or contact lenses. “Low vision rehabilitation involves providing patients with vision enhancing and assistive devices,” Stelmack said. “They’re taught new strategies and adaptations to improve their ability to function independently, despite impaired vision. So the goal of the research program I’ve been involved in here at Hines is to measure the outcomes of low-vision rehab programs in the VA system, and to provide an evidence base to guide clinical care and service delivery.”
Stelmack has led two large-scale clinical trials of low-vision rehabilitation programs within the VA. The VA Low Vision Intervention Trial (VA LOVIT), reported in 2008, validated the outpatient model for treating low vision, and provided a low-cost model for expanding outpatient services at VA centers. A second trial currently underway, VA LOVIT II, conducted among 330 patients at nine different VA centers, is comparing the effectiveness of two types of treatment in the VA continuum of care: basic low-vision care, where the patient undergoes an optometry examination and is prescribed a low-vision aid such as a hand-held or electronic magnifier; and interdisciplinary care, where the patient also receives therapy and homework assignments that provide instruction in the use of devices and in the use of remaining vision.
Stelmack is at work now on a pilot study designed to improve outcomes for an increasingly older population of veterans, many of whom have cognitive impairments. “When I first came to VA,” she said, “my average patients were in their 60s. Today, I cannot tell you how many patients I see in their 90s. It’s a totally different population, and we have to change our service delivery to be most appropriate to the patients that we serve.”
At the VA Rehabilitation Research and Development Service’s Center for the Prevention and Treatment of Visual Loss in Iowa City, Iowa, investigators focus on strategies to maximize early detection, and possibly prevention, of vision loss. According to Dr. Randy H. Kardon, who directs the center, one of the biggest obstacles to early detection is simply access to an eye clinic; many veterans who live in rural areas, or who have limited mobility, may not have contact with an eye care professional before the progression of a disorder – diabetic retinopathy, glaucoma, or macular degeneration, for example – has gone too far to be treatable.
Investigators at the Center for the Prevention and Treatment of Visual Loss are developing tools that can deliver vision care more easily and closer to home – for example, with sophisticated imaging devices that can be used without any special training by technicians in outpatient clinics. The devices take known imaging technologies – a retina camera, for example, used to image the retina and the optic nerve; or optical coherence tomography (OCT) – and add a layer of software. “We’re trying to develop software tools that would automatically analyze the imaging and say whether the person needs to be seen in the near future or urgently by a VA medical center or an eye specialist,” said Kardon. “The device would be useful not only for diagnosis of disorders, but also for following the course and monitoring treatment of these different disorders.”
The center is also developing ways to monitor eye functioning remotely – for example, an objective functional test of the pupillary light reflex (PLR) that can be performed using a small portable device. Such a device could be used by veterans in their own homes, said Kardon: “They could test and monitor their own visual function longitudinally over time, to see whether treatment for some of these common disorders is on track, or whether the treatment needs to be changed or be more aggressive.”
In a preliminary examination of the eyes of rats that had undergone experimental blast injuries, Fliesler noted molecular changes in retinal cells that indicated a degenerative process likely caused by oxidative stress – essentially, a failure to detoxify the effects of free radicals within cells.
Evaluations of these remote devices have suggested a new line of research for the center’s investigators, Kardon said: Veterans who have suffered head trauma display an abnormal PLR in the acute phase, and over the longer term, imaging devices often reveal a loss of nerve fibers in the retina after a concussion. “There is a concern about whether there is any progression of neurologic and visual deficits even after the injury has happened,” said Kardon. “So we’re studying this in veterans over time with recent funding, to see whether there is evidence for progression using the eye and the visual system as a window onto the brain.”
Inside the Eye
The findings of investigators at the VA’s Center for the Prevention and Treatment of Visual Loss are consistent with those found by other VA researchers. In a study reported in the New England Journal of Medicine in 2011, Dr. Glenn Cockerham, an ophthalmologist and researcher with the VA Palo Alto Health Care System, reported that among a group of Afghanistan and Iraq veterans who had sustained blast-induced traumatic brain injury (TBI), 43 percent had also suffered internal injuries to the eye that might have gone undetected in a functional examination. Many veterans with blast-related vision loss don’t report any trouble seeing until three or four months after the initial injury.