Weightlifting linked to eye risk

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Weightlifting linked to eye risk
Eye Care

Now that the holiday feasting is over, many people step up their exercise regimes to burn off those extra pounds. But new research shows that you may want to take extra precautions before hitting the weight machines.

Weightlifting may increase pressure in eyes

Researchers in Brazil have found that lifting heavy weights, especially while holding the breath, was linked to an increase in intraocular pressure, or pressure inside the eye.

They warned that this could increase the risk of glaucoma, a disease in which unusually high pressure within the eyeball damages the optic nerve and can result in permanent vision loss.

The results of the Brazilian study appeared in the September issue of Archives of Ophthalmology, a JAMA publication.

Aerobics vs weightlifting

Intraocular pressure is usually decreased after aerobic exercises such as running and biking. But weightlifting appears to have the opposite effect – especially when combined with the Valsalva manoeuvre, which involves exhaling forcibly with the mouth and nose closed.

This phenomenon also occurs in individuals who play wind instruments, particularly the trumpet, and when a person coughs or vomits.

The study was led by Dr. Geraldo Magela Vieira, M.D., of the Institute of Specialized Ophthalmology and UNIPLAC School of Medicine in Brasília, Brazil. Vieira and his team measured intraocular pressure during weightlifting in 30 males age 18 to 40 who all had normal eye pressure and did not have glaucoma.

The bench press test

The participants did four repetitions of a bench press exercise in two ways. During the first rep, pressure was measured in the right eye and the weightlifters held their breath during the last repetition. The second time, pressure was measured in the left eye and the participants breathed normally throughout the exercise. Eye pressure was measured during the fourth repetition.

During the first round of exercise, intraocular pressure increased in 27 of the 30 participants, by an average of 4.3 mm of mercury. During the second round, pressure increased in just 18 of the men by an average of 2.2 mm of mercury.

Breath-holding raises eye pressure

Vieira and his team speculated that the increased eye pressure could be due to the Valsalva manoeuvre and the "greater intrathoracic [chest] pressure caused by the air retained in the lungs when the subjects held their breath during intraocular pressure measurement." The authors also note that a certain type of glaucoma (normal-tension glaucoma) is more common in individuals who are subjected to frequent changes in eye pressure.

Caution to glaucoma patients

"Prolonged weightlifting could be a potential risk factor for the development or progression of glaucoma,” they wrote. “Intermittent intraocular pressure increases during weightlifting should be suspected in patients with normal-tension glaucoma who perform such exercises," they conclude.

"Patients with normal-tension glaucoma should be questioned as to a history of regular weightlifting."

CNIB is a nationwide, community-based, registered charity committed to research, public education and vision health for all Canadians. CNIB provides the services and support necessary for people to enjoy a good quality of life while living with vision loss. To find out more, visit us at www.cnib.ca or call 1-800-563-2642