Being in the field of Optometry, it is of great interest for me to read up on the impact of yoga on eye conditions, particularly glaucoma. There are many yoga asanas with high blood pressure being as one of the contraindications or a note to remember that people with hypertension should not hold certain poses for long. What about glaucoma?
What is glaucoma?
In general, glaucoma is an eye condition in which the normal fluid pressure inside the eyes slowly rises and damages the delicate nerve fibres of the optic nerve, leading to vision loss – or even blindness. These delicate nerve fibres are responsible for carrying visual signals from your eye to the brain. This damage is irreversible and can lead to blindness in advanced cases. In Singapore, Glaucoma accounts for 40% of blindness.
However, there are many types of glaucoma and the following are the more common tyoes:
1) Open-angle glaucoma: There are typically no early warning signs or symptoms.
2) Angle-closure glaucoma / Narrow-angle glaucoma:Caused by blocked drainage canals in the eye, resulting in a sudden rise in eye pressure. Symptoms to note may include:
- Hazy or blurred vision
- The appearance of rainbow-colored circles around bright lights
- Severe eye and head pain
- Nausea or vomiting (accompanying severe eye pain)
- Sudden sight loss
3) Low-tension or normal-pressure glaucoma: The optic nerve is damaged even though the pressure in the eye is not very high.
This doesn’t mean that people with glaucoma can’t do yoga, but a better understanding of how eye pressure is affected by headstand positions will allow people with glaucoma to avoid certain poses and adjust their routines for a safe and healthy experience.
Researches have reported that stress may play a significant part in the precipitation of acute closed-angle glaucoma because the eye pressure can be affected by the emotional state of a person. Stress reduction might prevent angle closure and reduce the eye pressure. Some suggested methods for stress reduction in yoga practice includes meditation, and relaxation exercises.
Some articles claimed that the asanas to be avoided include all inverted postures such as sirsasana (headstand), sarvangasana (rabbit pose), halasana (plough pose) and mastyasana (fish pose). Others that may increase the eye pressure are dhanuransana (bow pose), chakrasana (wheel pose), kapalabhati and vamana dhauti and hence, should be avoided.
Previous research that had tested only the headstand position, showed a significant two-fold rise in eye pressure. Another study had two groups of participants, one with no eye-related conditions and the other being people with glaucoma. They performed a series of inverted yoga positions, including downward facing dog, standing forward bend, plow, and legs up the wall. Eye pressure was captured in each group at various time points, including whilst seated, assuming the pose and at rest. Both normal and glaucoma participants showed a rise in eye pressure in all four yoga positions, with the greatest increase of pressure occurring during downward facing dog. While there was no significant difference between the two groups, more studies over longer durations of practicing the inverted positions is required.
In a class when head balance or inversions are being practised, some good alternatives for people with glaucoma are:
- Supta Virasana (Reclining Hero Pose)
- Supta Baddha Konasana (Reclining Bound Angle Pose)
- Supported Setu Bandhasana (Bridge Pose), with eyes fully covered and a low bridge
- Forward bends like Parsvottanasana (Intense Side Stretch Pose), Uttanasana (Standing Forward Bend) and Prasarita Padottanasana (Intense Spread Leg Stretch) can have the head elevated, with torso and head resting on a bench
In conclusion, teachers can caution people with glaucoma or at higher risk of having glaucoma to practice inversions with more awareness and care.
~ D.Tan (200hr YTT, Sep) ~