Updated March 11, 2014.

Written or reviewed by a board-certified physician. See About.com's Medical Review Board.

What is Glaucoma?

Glaucoma is an eye condition that occurs when the optic nerve is damaged due to elevated pressure in the eye. One possible cause of the increase in pressure is excess fluid in the eye, either because too much fluid is being produced or due to a drainage problem. Sometimes, the cause cannot be determined. About three million Americans have this condition, according to the American Glaucoma Society, though many more cases may go undiagnosed.

There is no cure for glaucoma, which can lead to blindness if left untreated. Some patients can regulate their intraocular pressure with daily eye drops, while others require laser treatment or surgery.

Glaucoma and Yoga

People with glaucoma who do yoga are advised to avoid full inversions like headstand, handstand, shoulderstand, and forearm stand, since several studies have shown that headstands cause potentially dangerous increases in intraocular pressure. A recent study that will be presented at the American Glaucoma Society meeting in February, 2014, examines changes in intraocular pressure relating to four milder yoga inversions: downward facing dog, standing forward bend, plow, and legs up the wall. 

Study Explanation 

Jessica Jasien, Gustavo de Moraes, and Robert Ritch performed a small study in 2013 at the New York Glaucoma Research Institute at New York Eye and Ear Infirmary of Mount Sinai on the effects of the four poses listed above on eye pressure, using ten control patients and ten patients with glaucoma.

The subjects held each pose for two minutes. The researchers measured their intraocular pressure five times: before they began (the baseline), as soon as they assumed the pose, two minutes into the pose, seated immediately after the pose, and ten minutes after the pose. 

Study Results

Pressure was seen to increase markedly from the baseline soon as the subjects began the poses, but did not go up much more by the two minute mark. When the measurements were taken after the subjects returned to a seated position and again after waiting ten minutes, the pressure in most cases remained slightly elevated from the baseline. There was no significant difference between the reactions of the control subjects and the glaucoma subjects. The greatest increase of pressure occurred during downward facing dog.

Recommendations

Dr. Ritch, who is a Professor of Ophthalmology at New York Medical College and the Chief of Glaucoma Service and Surgeon Director at New York Eye and Ear Infirmary, feels that the list of prohibited poses for people with glaucoma should be expanded beyond headstand to include the four poses in this study. Since many people have glaucoma but don't know it, he also recommends that people who do a lot of yoga should be screened so they can practice as safely as possible.

Can Yoga Cause Glaucoma?

Dr. Ritch is also interested in investigating whether holding a headstand for a long time (10+ minutes) each day, as is done in some yoga practices, could cause glaucoma after some years of practice. This is based on a case he treated, but has not yet been studied. 

Sources:

American Glaucoma Society, http://www.americanglaucomasociety.net

Baskaran M et al. Intraocular pressure changes and ocular biometry during Sirsasana (headstand posture) in Yoga practitioners. Ophthalmology 2006;161:1327-1332.

Gallardo MJ et al. Progression of glaucoma associated with the Sirsasana (headstand) yoga posture. Adv Ther. 2006;23:921-5.

Email and telephone communication with Dr. Robert Ritch and Jessica Jasien, January-February, 2014