Exercise can slow or prevent vision loss, study finds

We know regular exercise and a balanced diet are important for general wellbeing and protecting against many health conditions – including protecting your eye health.

But, until now, there hasn’t been enough research to determine whether it can delay the effects of macular degeneration.

A new study from the University of Virginia (UVA) School of Medicine has found that 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.

The study found that exercise reduced the harmful overgrowth of blood vessels in the eyes of lab mice by up to 45%. It represents the first experimental evidence showing that exercise can reduce the severity of macular degeneration.

Researcher Bradley Gelfand, PhD, of UVA's Center for Advanced Vision Science, said: "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.”

But Gelfand says those kinds of studies are prone to self-reporting errors.

What was the study?

The UVA team set up a series of mouse experiments to investigate whether exercise directly affects macular degeneration. Two groups of mice were compared, one group with an exercise wheel in the cage, and another group without the wheel. The voluntary nature of the exercise was important as forced exercise exerts a number of stress responses that could negatively influence the results.

After four weeks the researchers used lasers to induce a form of eye damage called choroidal neovascularization (CNV), a major factor in many age-related forms of vision loss that involves an overgrowth of blood vessels in a certain part of the eye. The researchers modelled this vision loss factor in the mice through laser-induced CNV.

What did researchers find? 

Across two experiments the researchers discovered blood vessel overgrowth in the exercising mice was between 32 and 45 percent lower than in the mice without access to voluntary exercise.

However, the results found that exercising following the laser injury did not improve the damage caused by leaking blood vessels. Only the mice with the pre-conditioning of exercise displayed reductions in the subsequent eye damage.

Researchers say this suggests a small amount of exercise does seem to help prevent damage caused by certain types of degenerative vision loss.

What's next? 

The research team at UVA hopes to further investigate how and why this happens to see if they can potentially develop a pill or treatment which can mimic the benefits of exercise, without having to exercise.

Read the full study in the journal Investigative Ophthalmology & Visual Science.?