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MONDAY, Jan. 24, 2022 (HealthDay News)
Injection medications can save the vision of older people with macular degeneration, but the ongoing regimen is taxing. Now a preliminary study raises the possibility that some patients can safely be "weaned off" the treatment.
Researchers found that of just over 100 patients they treated with the eye injections, nearly one-third were able to "pause" the therapy within the first year. And of those followed for at least two years, most did not need to restart.
Experts stressed that the findings are early and do not identify which patients might safely take a treatment break, or possibly even stop.
"Weaning is an interesting concept," said Dr. Emily Chew of the National Eye Institute (NEI) in Bethesda, Md., which helped fund the research.
But at the moment, she said, it is not a standard practice, and one of the big questions is: How do you "pick" patients who can stop treatment without endangering their vision?
Age-related macular degeneration, or AMD, is the leading cause of vision loss in the United States, according to the NEI. The disease damages the macula, a part of the eye's retina that is responsible for sharp, straight-ahead vision.
In the most serious form, called "wet" AMD, new blood vessels form in the back of the eye, leaking blood and other fluids, and scarring the macula. Not long ago, Chew said, patients with the condition would suffer rapid vision loss.
But in 2006, the first anti-VEGF medication was approved to treat wet AMD. VEGF, which stands for vascular endothelial growth factor, is a protein that promotes new blood vessel growth. Blocking it in the eye can stabilize wet AMD in most people, and improve vision in some.
"We are very lucky to have these drugs," Chew said. "This is a highly successful therapy."
The problem, though, is the burden of regular trips to the eye doctor, indefinitely.
"It's difficult not only for patients, but for the family members who have to take them to their appointments," said Dr. Akrit Sodhi, lead researcher on the new study.
Trials of anti-VEGF drugs used a treatment frequency of every one to two months. But in the real world, where practicality and costs come up, doctors try different tactics, according to Sodhi, an associate professor of ophthalmology at Johns Hopkins University School of Medicine in Baltimore.
That includes a "treat and extend" approach: Patients who respond particularly well to the injections have their treatment interval gradually extended.
The question, Sodhi said, is whether some patients can ultimately be weaned off treatment.
For the current study — published online Jan. 18 in the Journal of Clinical Investigation — Sodhi's team reviewed records from 106 patients treated between 2013 and 2020.
Overall, 31% successfully paused anti-VEGF injections within the first year — meaning their eyes showed no fluid buildup or worsening vision for at least 30 weeks off treatment. A handful of other patients were weaned off during year two.
Twenty-two patients were successfully weaned off treatment and followed for at least two years. Of that group, 73% remained treatment-free at the end of year two.
What's clear is that there is no one-size-fits-all regimen for all patients, according to Dr. Rahul Khurana, a clinical spokesman for the American Academy of Ophthalmology.
"This disease is chronic, variable and unpredictable," said Khurana, who was not involved in the study.
After initial trials using monthly injections, doctors learned that that was likely "over-treating" patients and the intervals could be extended, he said.
But whether some can ultimately stop remains an open question, Khurana said. The risk of suspending treatment is that any recurrence of new blood vessel growth could cause vision loss that is not always recovered, he noted.
If researchers can find objective markers that predict patients' likelihood of responding especially well to anti-VEGF injections, that would help. And Sodhi's team found that patients successfully weaned off treatment differed from other patients in their levels of certain proteins in their eye fluids.
Sodhi said more research is needed to see whether any of those proteins can predict treatment responses. As for treatment pauses, he said, no recommendations can be made until larger studies test the concept.
Both Chew and Khurana said there are other ways, both available and under study, to ease patients' treatment burden.
Last year, U.S. regulators approved Susvimo, a version of the anti-VEGF drug Lucentis that is delivered via a tiny implant in the eye. It requires only two visits a year for refills.
And, Chew said, studies are testing whether giving AMD patients equipment for home monitoring can reduce the need for office visits.
The National Eye Institute has more on age-related macular degeneration.
SOURCES: Akrit Sodhi, MD, PhD, associate professor, ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore; Emily Chew, MD, director, division of epidemiology and clinical applications, National Eye Institute, Bethesda, Md.; Rahul Khurana, MD, clinical spokesman, American Academy of Ophthalmology, San Francisco; Journal of Clinical Investigation, Jan. 18, 2022, online
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