Head-down yoga poses increase eye pressure in glaucoma patients
Four common yoga poses have been shown to increase intraocular pressure (IOP), a known risk factor for people with glaucoma.
A new study found that when people did head-down poses, their IOP increased within one minute of doing each pose. The increase remained throughout each two-minute pose, then IOP returned to baseline within two minutes of the person sitting down.
"For people with glaucoma, the optic nerve is compromised to some extent. Once the nerve becomes damaged, its ability to withstand repeated acute IOP elevations is reduced," says Murray Fingeret, O.D., chief of the optometry section, Brooklyn/St. Albans Campus, Department of Veterans Administration, at New York Harbor Health Care System, and a founding member and past president of the Optometric Glaucoma Society. "What this paper showed is when a person puts him or herself in a position where his or her head is lowered, the eye pressure goes up and the eye pressure goes up fairly quickly. You're looking at a greater than 10-point increase that occurs almost immediately."
The prospective, observational study compared 10 people with glaucoma to 10 people without the disease in 2013 at the Einhorn Clinical Research Center, New York Eye and Ear Infirmary, in New York City.
The poses were downward-facing dog, standard forward-bend pose, plow pose and legs-up-the-wall pose, performed in that order within one hour. The greatest IOP increase occurred with downward-facing dog, in which a person starts on his or her hands and knees, then rises with the legs and arms straight, hands and feet still on the ground, hanging the head.
IOP increased in all participants during all four poses. The difference in elevated IOP between the glaucoma and control groups was not statistically significant, but people who already have glaucoma are more at risk from IOP increases.
Previous studies on glaucoma and yoga only tested the handstand position, according to the researchers. Dr. Fingeret says reports have suggested over the years that things such as using inversion boots—a fad in the 1980s—and playing a horn instrument could elevate IOP, but that there have been no studies to show if such pressure damages the optic nerve long term. The new study doesn't show how the increase might affect people with glaucoma over time either.
"We assume these short bursts of elevated eye pressure are damaging, but there's no evidence," Dr. Fingeret says. "The message is that if you have patients who appear to be getting worse with glaucoma and appear to be well-controlled, one of the things to inquire about is their exercise and if they do yoga."
The AOA follows all research closely, including potential risk factors for people with glaucoma. Although this study is important, more research is needed to understand the potential long-term effects.
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