Intraocular Pressure Rise in Subjects with and without Glaucoma during Four Common Yoga Positions

Abstract

Purpose: To measure changes in intraocular pressure (IOP) in association with yoga exercises with a head-down position.

Methods: The single Center, prospective, observational study included 10 subjects with primary open-angle glaucoma and 10 normal individuals, who performed the yoga exercises of Adho Mukha Svanasana, Uttanasana, Halasana and Viparita Karani for two minutes each. IOP was measured by pneumatonometry at baseline and during and after the exercises.

Results: All yoga poses were associated with a significant (P < 0.01) rise in IOP within one minute after assuming the yoga position. The highest IOP increase (P < 0.01) was measured in the Adho Mukha Svanasana position (IOP increase from 17 ± 3.2 mmHg to 28 ± 3.8 mmHg in glaucoma patients; from 17 ± 2.8 mmHg to 29 ± 3.9 mmHg in normal individuals), followed by the Uttanasana position (17 ± 3.9 mmHg to 27 ± 3.4 mmHg (glaucoma patients) and from 18 ± 2.5 mmHg to 26 ± 3.6 mmHg normal individuals)), the Halasana position (18 ± 2.8 mmHg to 24 ± 3.5 mmHg (glaucoma patients); 18 ± 2.7 mmHg to 22 ± 3.4 mmHg (normal individuals)), and finally the Viparita Kirani position (17 ± 4 mmHg to 21 ± 3.6 mmHg (glaucoma patients); 17 ± 2.8 to 21 ± 2.4 mmHg (normal individuals)). IOP dropped back to baseline values within two minutes after returning to a sitting position. Overall, IOP rise was not significantly different between glaucoma and normal subjects (P = 0.813), all though glaucoma eyes tended to have measurements 2 mm Hg higher on average.

Conclusions: Yoga exercises with head-down positions were associated with a rapid rise in IOP in glaucoma and healthy eyes. IOP returned to baseline values within 2 minutes. Future studies are warranted addressing whether yoga exercise associated IOP changes are associated with similar changes in cerebrospinal fluid pressure and whether they increase the risk of glaucoma progression.

Trial registration: ClinicalTrials.gov #NCT01915680.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1. CONSORT Flow Diagram.

Fig 2. Scheme Illustrating the Various Yoga Positions.

Fig 3. Histogram and test for homoscedasticity of the mixed effects linear model.

Fig 4. Least squares means and mean values of the covariates of the changes in IOP in the Adho Mukha Svanasana position over time.

The X axis represents each time point an IOP measurement was taken (0 = Baseline seated; 1 = Immediate position; 2 = 2 minutes position; 3 = Post position seated; and 4 = 10 minutes post position seated). The Y axis represents the IOP in mmHg after adjusting for the covariates. Subjects with glaucoma diagnosis are depicted ‘Glaucoma = 1’; controls are ‘Glaucoma = 0’.

Fig 5. Least squares means and mean values of the covariates of the changes in IOP in the Uttanasana position over time.

The X axis represents each time point an IOP measurement was taken (0 = Baseline seated; 1 = Immediate position; 2 = 2 minutes position; 3 = Post position seated; and 4 = 10 minutes post position seated). The Y axis represents the IOP in mmHg after adjusting for the covariates. Subjects with glaucoma diagnosis are depicted ‘Glaucoma = 1’; controls are ‘Glaucoma = 0’.

Fig 6. Least squares means and mean values of the covariates of the changes in IOP in the Halasana position over time.

The X axis represents each time point an IOP measurement was taken (0 = Baseline seated; 1 = Immediate position; 2 = 2 minutes position; 3 = Post position seated; and 4 = 10 minutes post position seated). The Y axis represents the IOP in mmHg after adjusting for the covariates. Subjects with glaucoma diagnosis are depicted ‘Glaucoma = 1’; controls are ‘Glaucoma = 0’.

Fig 7. Least squares means and mean values of the covariates of the changes in IOP in the Viparita Karani position over time.

The X axis represents each time point an IOP measurement was taken (0 = Baseline seated; 1 = Immediate position; 2 = 2 minutes position; 3 = Post position seated; and 4 = 10 minutes post position seated). The Y axis represents the IOP in mmHg after adjusting for the covariates. Subjects with glaucoma diagnosis are depicted ‘Glaucoma = 1’; controls are ‘Glaucoma = 0’.

Fig 8. Predictive Margins of Diagnostic Groups versus Time with 95% Confidence Intervals.

Fig 9. Predictive Margins of Yoga Pose versus Time with 95% Confidence Intervals.