Glaucoma is a chronic optic neuropathy leading to permanent vision loss, a condition that primarily begins undetected, and intraocular pressure (IOP) is the only modifiable risk factor to halt its progression.
Can changing the lifestyle pattern and practicing yoga help patients who are prone to glaucoma or those already diagnosed and taking treatment is the question we need to understand and answer. I would like to congratulate the authors of the present review article “Effect of yoga on intraocular pressure in patients with glaucoma: A systematic review and meta-analysis”.
India is the land of yoga; though yoga belongs to the world, it has a home and originated in India about centuries ago. Yoga is the most popular form of exercise practiced globally, more so after the Covid 19 pandemic. Glaucoma management requires a holistic approach to prevent further loss of vision, especially among patients showing progression in spite of appropriate medication and surgical intervention. Studies have shown that yoga and meditation are helpful in glaucoma by reducing IOP through various mechanisms like decreasing serum cortisol, augmenting blood flow and brain oxygenation, lowering oxidative stress, increasing nitric oxide, and decreasing inflammation and thereby preventing glaucoma progression.
Glaucoma patients have also shown signs of increased depression and anxiety due to the stress of potentially losing sight and increased production of certain chemicals and hormones to help combat the stress. It has been found that mindful meditation helps glaucoma patients by improving brain oxygenation upgrading the quality of living and regressing further progression of the disease. Also, vascular factors play a vital role in glaucoma, and mindfulness-based stress reduction exercises modulate gene expression and also optic disc perfusion, which is documented by optical coherence tomography angiography (OCTA) in primary open angle glaucoma (POAG).
IOP is under the influence of the autonomic nervous system, which modifies the production or drainage of aqueous humor. Besides meditation, various breathing techniques of yoga have been shown to alter the brain hemisphere activity and also influence the autonomic nervous system. Multiple studies on pranayama that quantified IOP fluctuations during various breathing techniques concluded that right nostril breathing “Suryanadi pranayama,” left nostril breathing which is known as “Chandranadi pranayama,” and alternate nostril breathing “Anuloma villoma pranayama” are safe and do not increase IOP in normal subjects. Right nostril breathing increases sympathetic activity, and left nostril breathing brings the dominance of parasympathetic activity and have a beneficial effect on lowering IOP. Also, meditation, yoga, and Pranayama have been shown to have an effect on nitric oxide in the body, which has an IOP-lowering effect by increasing the outflow of aqueous at the trabecular meshwork.
Posture-related IOP fluctuations are directly related to the inclination of the body toward the completely inverted position. IOP begins to rise upon assuming a head down position can result in doubling of the IOP with the body vertical and remains elevated as this position is maintained. Four yogic postures demonstrated adversely affected blood flow toward the optic nerve and Adho Mukha Svanasana position, the Uttanasana position, the Halasana position, and Viparita Kirani position of yoga asana are associated with raised IOP so best to be avoided in glaucoma [Fig. 1].
Yoga can work like a double-edged sword besides few positions having detrimental effects on glaucoma; there are various beneficial effects of yogabased ocular exercises in glaucoma patients too. Tratak kriya involves accommodating and deaccommodating the eyes by ciliary muscle contraction and relaxation, which in turn modifies the outflow of the aqueous humor and reduces IOP to slow down the progression of glaucoma. Tratak requires continuous staring at a near small object like the flame of a candle placed a few feet away from the eyes or at distant objects like tree, sun, star, or moon for as long as possible or until the watering of the eyes starts. Tratak kriya is effective in reducing IOP as well as stress and improving the quality of life in glaucoma patients.
The main aim of glaucoma management is to improve the quality of life and prevent further progression of the disease. Allostatic load, which refers to the cumulative burden of chronic stress and life events, has important implications for glaucoma. Therefore, besides diagnosis and treatment, we should also make an effort to evaluate the allostatic load in glaucoma patients and suggest dietary as well as other lifestyle modifications to reduce it. This may prove to be a useful adjunct tool to improve the quality of life in glaucoma patients and might be helpful in the prevention of the onset of this disorder in highrisk individuals. Further studies are required to evaluate long-term effects of all these modalities of treatment and there is a need to study larger numbers of patients to standardize the treatment protocol to fight the irreversible blindness of glaucoma.
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