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MedicalResearch.com Interview with:
Robert Ritch, MD, FACS
Shelley and Steven Einhorn Distinguished Chair
Professor of Ophthalmology
Surgeon Director Emeritus and Chief, Glaucoma Services
Founder, Medical Director and Chairman, Scientific Advisory Board
The Glaucoma Foundation
Jessica V. Jasien MEn
Einhorn Clinical Research Center
The New York Eye and Ear Infirmary of Mount Sinai
New York, NY 10003
Medical Research: What is the background for this study? What are the main findings?
Response: Glaucoma is the leading cause of irreversible blindness in the United States and elevated intraocular pressure (IOP) is the most common known risk factor for glaucomatous damage. At the current time, IOP is the only modifiable risk factor for which treatment has a proven effect on preventing or slowing the progress of the disease.
The story behind this study goes back to 1980, when we saw a 45-year-old woman with severe damage from normal-tension glaucoma, which then was thought to be a disease of the elderly and also thought to be rare, which we now realize was erroneous. The causes of normal-tension glaucoma were also poorly understood. It turned out on questioning that this particular patient had been performing yoga and standing on her head for 20 minutes a day for 20 years. We measured her IOP in this position and it rose from 15 mmHg in the sitting position to 60 mmHg. When measured lying flat, it was 30 mmHg. We measured everyone working in the department standing on their heads and the IOP roughly doubled in each of them. This was our first inkling that marked changes in IOP could result from changes in body position.
The background for this study came from the lack of knowledge of IOP rises during yoga inversions, other than the headstand position. We looked at four common inverted yoga positions in glaucoma patients and healthy patients who were all experienced in practicing yoga. The four positions tested were downward facing dog, plow, legs up the wall, and forward bend. Each position showed a direct increase in IOP immediately assuming the yoga position, however the IOP dropped once assuming the seated position after two minutes in the yoga position. The most significant increase in IOP was seen during the downward facing dog position. IOP of each study participant was taken seated (baseline), immediately assuming the yoga position, which was held for two minutes, again at the two minutes of the yoga position, immediately in the seated position following the yoga position, and again after 10 minutes in the seated position. Each position was tested once in this order of IOP measurements.
Medical Research: What should clinicians and patients take away from your report?
Response: Patients who practice yoga should be aware of these increases in IOP during inverted positions. Patients who suffer from glaucoma or have a family history of glaucoma may want to speak to their yoga instructors and modify inverted positions. Positions can be modified to not complete a full inversion with the use of chairs or blocks during practice.
Clinicians should also be aware of the increase in IOP during inverted yoga positions and share this information with their patients. This can be accomplished by clinicians asking their patients if they practice yoga. This will then allow for clinicians to be aware, the patients, and the patients also making their yoga instructors aware.
Medical Research: What recommendations do you have for future research as a result of this study?
Response: We do not know if the effects of the short-term rises in IOP in patients assuming these positions has clinical significance in patients with glaucoma or whether they can predispose to the development of glaucoma in patients without the disease. One might think that patients with severe glaucoma damage would have a greater chance of worsening their conditions over a long period of time, but that remains to be studied formally. On the results of this prospective study, a longitudinal study looking at the long term effects of yoga practice on IOP and the progression of glaucoma should be completed. The length of individual daily practice and positions can be assessed, as well as the comparison of the length of time being a yoga practitioner with the progression of their glaucomatous damage. This would allow for a more thorough understanding of the effects of yoga inversions on glaucoma progression.
Intraocular Pressure Rise in Subjects with and without Glaucoma during Four Common Yoga Positions
Jessica V. Jasien ,Jost B. Jonas,C. Gustavo de Moraes, Robert Ritch
Published: December 23, 2015
Robert Ritch, MD, FACS, & Jessica V. Jasien MEn (2016). Glaucoma Patients Might Want To Avoid Downward Dogs