Exercise can slow or prevent the development of macular degeneration and may benefit other common causes of vision loss, such as glaucoma and diabetic retinopathy, according to new research.
The new study from the University of Virginia School of Medicine found that exercise reduced harmful blood vessel proliferation by up to 45% in the eyes of lab mice. This tangle of blood vessels is a key contributor to macular degeneration and several other eye diseases.
The study represents the first experimental evidence showing that exercise can reduce the severity of macular degeneration, one of the leading causes of vision loss, the scientists report. It is estimated that ten million Americans have the condition.
“It has long been asked whether maintaining a healthy lifestyle can delay or prevent the development of macular degeneration. Historically, the answer to this question has been to survey people, ask them what they eat and how much exercise they perform,” said researcher Bradley Gelfand, PhD, of UVA’s Center for Advanced Vision Science. “This is basically the most sophisticated study that’s been done. The problem with this is that people are notoriously bad self-reporters…and that can lead to conclusions that may or may not be true. [study] offers hard evidence from the lab for the very first time.”
The benefits of exercise
Attractively, the research found that the bar for receiving exercise benefits was relatively low – more exercise did not mean more benefit. “Mice are a bit like people in that they will do an array of exercises. As long as they had a wheel and ran on it, there was an advantage,” Gelfand said. “The benefit they got is saturated at low levels of exercise.”
A first test comparing mice that voluntarily exercised with those that did not found that exercise reduced blood vessel proliferation by 45%. A second test, to confirm the results, found a 32% reduction.
Scientists don’t know exactly how exercise prevents blood vessel proliferation. There could be a variety of factors at play, they say, including increased blood flow to the eyes.
Gelfand, from UVA’s Department of Ophthalmology and Department of Biomedical Engineering, noted that the onset of vision loss is often associated with decreased exercise. “It’s fairly well known that when people’s eyes and vision deteriorate, their tendency to engage in physical activity also decreases,” he said. “It can be difficult to study in older people. … To what extent does one cause the other?”
Researchers have already submitted grant proposals in hopes of obtaining funds to pursue their discoveries.
“The next step is to look at how and why this happens, and see if we can develop a pill or method that will give you the benefits of exercise without having to exercise,” Gelfand said. “We are talking about a fairly old population [of people with macular degeneration]many of whom may not be able to conduct the type of exercise regimen that may be necessary to see any kind of benefit. (He urged people to consult their doctor before starting any aggressive exercise program.)
Gelfand, a self-proclaimed couch potato, revealed a secret motivation for the research: “One of the reasons I wanted to do this study was kind of selfish. I was hoping to find a reason not to exercise,” said- he joked. “It turns out that exercise is really good for you.”
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Material provided by University of Virginia Health System. Note: Content may be edited for style and length.