Exercise can slow or prevent vision loss, study finds

Date:
July 1, 2020
Source:
University of Virginia Health System
Summary:
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, new research suggests.



FULL STORY ========================================================================== 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, new research suggests.


==========================================================================
The new study from the University of Virginia School of Medicine found
that exercise reduced the harmful overgrowth of blood vessels in the
eyes of lab mice by up to 45%. 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, a leading
cause of vision loss, the scientists report. Ten million Americans are estimated to have the condition.

"There has long been a question about whether maintaining a
healthy lifestyle can delay or prevent the development of macular
degeneration. The way that question has historically been answered has
been by taking surveys of people, asking them what they are eating and
how much exercise they are performing," said researcher Bradley Gelfand,
PhD, of UVA's Center for Advanced Vision Science. "That is basically
the most sophisticated study that has been done.

The problem with that is that people are notoriously bad self-reporters
... and that can lead to conclusions that may or not be true. This [study] offers hard evidence from the lab for very first time." The Benefits
of Exercise Enticingly, the research found that the bar for receiving
the benefits from exercise was relatively low -- more exercise didn't
mean more benefit. "Mice are kind of like people in that they will
do a spectrum of exercise. As long as they had a wheel and ran on it,
there was a benefit," Gelfand said. "The benefit that they obtained is saturated at low levels of exercise." An initial test comparing mice
that voluntarily exercised versus those that did not found that exercise reduced the blood vessel overgrowth by 45%. A second test, to confirm
the findings, found a reduction of 32%.

The scientists aren't certain exactly how exercise is preventing the
blood vessel overgrowth. There could be a variety of factors at play,
they say, including increased blood flow to the eyes.

Gelfand, of UVA's Department of Ophthalmology and Department of Biomedical Engineering, noted that the onset of vision loss is often associated with
a decrease in exercise. "It is fairly well known that as people's eyes and vision deteriorate, their tendency to engage in physical activity also
goes down," he said. "It can be a challenging thing to study in older
people. ... How much of that is one causing the other?" The researchers already have submitted grant proposals in hopes of obtaining funding to
pursue their findings further.

"The next step is to look at how and why this happens, and to see if we
can develop a pill or method that will give you the benefits of exercise without having to exercise," Gelfand said. "We're talking about a fairly elderly population [of people with macular degeneration], many of whom
may not be capable of conducting the type of exercise regimen that may be required to see some kind of benefit." (He urged people to consult their doctors before beginning any aggressive exercise program.) Gelfand,
a self-described couch potato, disclosed a secret motivation for the
research: "One reason I wanted to do this study was sort of selfish. I
was hoping to find some reason not to exercise," he joked. "It turned
out exercise really is good for you."

========================================================================== Story Source: Materials provided by
University_of_Virginia_Health_System. Note: Content may be edited for
style and length.


========================================================================== Journal Reference:
1. Ryan D. Makin; Dionne Argyle; Shuichiro Hirahara; Yosuke Nagasaka;
Mei
Zhang; Zhen Yan; Nagaraj Kerur; Jayakrishna Ambati; Bradley
D. Gelfand.

Voluntary Exercise Suppresses Choroidal Neovascularization in
Mice. IOVS, 2020 DOI: 10.1167/iovs.61.5.52 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/07/200701100025.htm

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