Pranayama is a form of yoga that focuses on breathing. In Sanskrit, prana translates to “vital life force” and yama translates to “gain control.” Since breath is linked to a person’s prana in yoga, the practice is meant to raise the “life energies,” or prana shakti.

Yogic pranayama and diaphragmatic (deep) breathing (YPDB) are known to stimulate the parasympathetic nervous system, often called the “rest and digest” mode (the sympathetic nervous system, conversely, is the “flight or fight” mode). 

A February 2021 study in the Journal of Glaucoma suggests that yogic pranayama, along with supplemental diaphragmatic breathing therapy, could help lower intraocular eye pressure (IOP) in primary open-angle glaucoma—the most common form of glaucoma worldwide. 

What Did the Researchers Do?

A team of researchers at All India Institute of Medical Sciences tested the combined effect of yogic pranayama and diaphragmatic breathing on intraocular pressure (IOP) in people with primary open-angle glaucoma to see whether it could be suggested as an adjunct therapy alongside standard medication. 

They thought that, because of the similarities between how glaucoma forms in the eye and stress-associated changes in the body, relaxation techniques such as yoga might be able to reduce IOP. Relaxation techniques had previously been reported to lower IOP and improve regulation of aqueous humor production in the eye.

• Ninety people over 40 years of age with moderate-to-severe primary open-angle glaucoma were randomized 1:1 to either a study group consisting of yogic pranayama and diaphragmatic breathing (YPDB) or to a control group.
• IOP was measured initially and then at one, three, and six months.
• YPDB group participants continued eye drop medication throughout the study and engaged in deep breathing for 30 minutes each morning.

What They Found

The researchers found significant results after six months:

• YPDB participants saw average IOP in their right eye go from 20.85 mm Hg at baseline to 14.90 mm Hg at six months and from 20.30 mm Hg to 14.25 mm Hg in their left eye. Likewise, controls saw average IOP in their right eye go from 19.51 mm Hg at baseline to 15.76 mm Hg at six months and from 19.32 mm Hg to 15.32 mm Hg in their left eye.
• That said, only YPDB participants had a significant within-group reduction in average IOP after six months, with 40 (89%) of YPDB participants achieving over a 28% reduction.

There were no negative effects and no changes in vision or optical coherence tomography (OCT).

What It Means

The study was limited in its lack of OCT and visual field data, as well as in the sample size and frequency of IOP measurement. 

Still, the researchers concluded that YPDB treatment could reduce IOP in people with primary open-angle glaucoma and can be advised as an adjunct therapy. At the same time, they cautioned not to use YPDB as a substitute for medications or treatment options such as eye drops, and that more research is needed to determine the effect of YPDB on vision loss.

Adding perspective to the study, ophthalmologist Navpreet Hehar, O.D., FAAO explains that the evidence of IOP reduction through controlled breathing is believed to be through a lowering of sympathetic nervous activity and increase in melatonin production, which decreased aqueous humor secretion. She emphasizes, however, that the only treatment options for reducing IOP are medications and surgery. She also reminds readers that “not all yoga exercises are created equal,” noting that certain poses—downward-facing dog in particular—can actually raise IOP.

Dr. Hehar’s bottom line, echoing the study authors:

“Yoga breathing exercises are not a substitute for glaucoma treatment, however, they can be recommended as adjuvant therapy for additional IOP lowering benefits for patients. Further research is warranted to understand the long-term effectiveness of these exercises in glaucoma management.”

*VanDewater, K. (2022, January 11). Yoga breathing exercises lower IOP in primary open-angle glaucoma. Healio. https://www.healio.com/news/optometry/20220111/yoga-breathing-exercises-lower-iop-in-primary-openangle-glaucoma