Weightlifting may stir risk of glaucoma-Study

Weightlifters may have a greater risk of developing a potentially devastating eye disease, glaucoma, a small Brazilian study appeared in the September issue of Archives of Ophthalmology, reveals.

Brazilian eye specialists found that weightlifting may trigger a temporary increase in pressure within the eye, with higher pressure occurring with breath-holding during a weightlifting exercise, which could predispose weightlifters to normal-tension glaucoma, a disease of the eye in which damage is caused by elevated pressure within the eye. The disease leads to damage to the optic nerve and gradual loss of eyesight.

Intraocular pressure, the fluid pressure inside the eye, is generally decreased after aerobic exercise, like running and biking, and non-aerobic exercise, including weightlifting.

In their study, Geraldo Magela Vieira, M.D., Institute of Specialized Ophthalmology and UNIPLAC School of Medicine, Brasilia, Brazil, and his fellow researchers measured intraocular pressure during weightlifting in 30 male bodybuilders age 18 to 40 (average age 26) without glaucoma, and whose intraocular pressure was in normal range at under 21mm of mercury.

Tests on volunteers showed that when they held their breath while performing bench press exercises, the pressure in their eyes increased significantly. Previous studies have indicated normal-tension glaucoma to be more widespread in people who experience frequent changes in eye pressure.

The participating bodybuilders performed four repetitions of a bench press exercise in two. In the first round, 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 bodybuilders breathed normally throughout the exercise. Eye pressure was measured during the fourth repetition.

For half of the repetitions each performed, the volunteers were asked to hold their breath, and for the rest to breathe normally. When the weightlifters held their breath, 27 participants (90%) experienced a rise in eyeball pressure of nearly 25% (by an average of 4.3 mm of mercury). When they breathed normally, it rose in 18 (62%) weightlifters by an average of 2.2 mm of mercury.

According to the researchers, the increased pressure could be due to the Valsalva manoeuvre (A strain against a closed airway combined with muscle tightening, such as happens when a person holds his or her breath and tries to move a heavy object) or a similar motion performed during bench presses.

Writing in the journal, the researchers conclude, “Prolonged weightlifting could be a potential risk factor for the development or progression of glaucoma. Intermittent intraocular pressure increases during weightlifting should be suspected in patients with normal-tension glaucoma who perform such exercises,” they further write, “Patients with normal-tension glaucoma should be questioned as to a history of regular weightlifting.”

Vieira, who headed the study team, said the problem might arise when air is forced against the closed windpipe and pressure increases in the chest. Breathing continuously throughout training would minimize the effect.