Effect of yoga-based interventions on intraocular pressure: A narrative review

Jayvindra Singh; VK Katiyar; Daya Shankar Singh; Niranjan Kala

doi:10.4103/jacs.jacs_29_22

REVIEW ARTICLE

Year : 2023 | Volume : 11 | Issue : 2 | Page : 85-90

Effect of yoga-based interventions on intraocular pressure: A narrative review

Jayvindra Singh, VK Katiyar, Daya Shankar Singh, Niranjan Kala
Department of Yoga, University of Patanjali, Patanjali Yogpeeth, Haridwar, Uttarakhand, India

Date of Submission	17-Oct-2022
Date of Acceptance	05-May-2023
Date of Web Publication	29-Aug-2023

Correspondence Address:
Mr. Jayvindra Singh
University of Patanjali, Patanjali Yogpeeth, Haridwar - 249 405, Uttarakhand
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jacs.jacs_29_22

Abstract

Chronic increase of intraocular pressure (IOP) is highly associated with the development of retinal ganglion cell death and exists as a primary risk factor for various eye disorders, including glaucoma, which is a leading cause of irreversible blindness. In recent years, an increased interest in using complementary and alternative therapies such as yoga has been seen for the treatment of glaucoma. This review is aimed at evaluating and understanding the studies on yoga-based exercises on IOP. Three databases, i.e. PubMed, Cochrane Library, and Google Scholar were searched, and 10 articles were included that met the criteria for inclusion. These studies involved different yoga-based practices such as trataka and eye movements, breathing exercises or pranayama, yoga postures, and meditation. The studies suggested that yoga practices were able to influence IOP levels in both healthy and clinical populations. Yoga postures were associated with an increase in IOP levels, whereas other yoga practices, i.e. eye exercises, pranayama, and meditation, reduced the IOP levels. Yoga-based eye exercises, such as palming, trataka, and eye movement and relaxation, appeared to have the most persistent effects. Yoga practices could decrease IOP levels; however, yoga postures should be contraindicated with patients with glaucoma and higher IOP levels.

Keywords: Glaucoma, intraocular pressure, meditation, yoga

How to cite this article:
Singh J, Katiyar V K, Singh DS, Kala N. Effect of yoga-based interventions on intraocular pressure: A narrative review. J Appl Conscious Stud 2023;11:85-90

How to cite this URL:
Singh J, Katiyar V K, Singh DS, Kala N. Effect of yoga-based interventions on intraocular pressure: A narrative review. J Appl Conscious Stud [serial online] 2023 [cited 2023 Dec 9];11:85-90. Available from: http://www.jacsonline.in/text.asp?2023/11/2/85/384450

Introduction

Intraocular pressure (IOP) serves as the fine-tuned balance between production and drainage of aqueous humor, the eye fluid. IOP is defined as the force exerted by the aqueous humor on the internal surface area of the anterior eye. Disruption in IOP accounts for the progression and development of various diseases such as glaucoma, uveitis, and retinal detachment (Machiele et al., 2022 and Moré et al., 2014). A sudden rise in IOP can cause mechanical stress and ischemic effects to the delicate structures of the eye, such as the retinal nerve fiber layer (Weinreb et al., 2014), whereas chronic increase of IOP is highly associated with the development of retinal ganglion cell death and exists as a primary risk factor for glaucoma which is a leading cause of irreversible blindness worldwide, with primary open-angle glaucoma (POAG) being most prevalent (Weinreb and Tee Khaw, 2004).

Globally, the prevalence of glaucoma is 3.54% for the population aged 40–80 years and is expected to increase from 76 to 111.8 million individuals between 2020 and 2040 (Tham et al., 2014). The first-line pharmacological treatment of glaucoma involves reducing the elevated IOP levels with drugs such as alpha-agonists, prostaglandins, and β-blockers, although the envisaged results of the current medical regimen are not satisfying and sufficient (Li et al., 2016; Lu et al., 2023; and Nocentini and Supuran, 2019). In recent years, an increased interest in using complementary and alternative therapies has been seen for the treatment of glaucoma (Rhee et al., 2001). Yoga is a physical, mental, and spiritual discipline that originated in ancient India. It primarily involves the practice of physical postures (asana), controlled breathing (pranayama), and meditation (dhyana). There are numerous health benefits associated with the practice of yoga, including stress reduction, disease prevention, and rehabilitation (Guddeti et al., 2019; Maddux et al., 2017). The practice of yoga has a long history and continues to be popular today due to its numerous documented health benefits. It is one of the most popular and widely used nonpharmacological interventions. The documented effects of yoga on stress reduction (Estevao, 2022), improvement of quality of life (Woodyard, 2011), and general well-being (Tulloch et al., 2018) make it a relatively safe and economical add on treatment for numerous conditions, including its potential effects on IOP. However, the evidence on the relationship between yoga and IOP is currently limited. Since lowering IOP is the primary goal of treatment in patients with pathologies such as glaucoma and ocular hypertension, review of the effects of yoga on IOP would provide a valuable resource for researchers and health-care practitioners. This review is aimed at evaluating and understanding the studies on yoga-based exercises on IOP in patients and healthy individuals and to provide a clearer understanding of the potential benefits and risks of incorporating yoga into a treatment or prevention plan for individuals with elevated IOP levels.

Methods

Search strategy

A systematic search was conducted across three databases (PubMed, Cochrane Library, and Google Scholar) from the inception to the present date (i.e. March 2022) using a set of keywords related to yoga and IOP and yoga and glaucoma. A total of 318 records were identified and were further screened. After reading titles and abstracts, 237 records were removed as they did not directly address the area of interest (did not involve yoga or IOP at all). An additional 71 records were excluded for reasons including duplication (39 articles), single-case studies (10 articles), review or descriptive articles (12 articles), reporting variables other than IOP (2 articles), and involving interventions other than yoga (8 articles). After filtering for these criteria, ten articles were selected for inclusion, and their full-text papers were obtained.

After getting the full papers of the selected studies, the details of their sample, study design, intervention given, assessments, findings, and adverse events were recorded.

Results

A total of 10 studies were selected, of which four involved yoga-based ocular exercises such as palming, relaxed eye movements, and trataka (a practice involving continuous gazing); three involved pranayama or yoga breathing exercises; two involved asana or yoga postures; and one involved a variation of meditation. These studies are discussed in detail below and are also presented in [Table 1].

Table 1: Details of the studies reviewed

Click here to view

Intraocular pressure and yoga-based ocular exercises

A randomized controlled trial examined the effects of yoga-based ocular exercises on IOP on 31 healthy undergraduate students of an optometry college assigned to a yoga group and a control group (Gupta and Aparna, 2019). The yoga-based ocular exercises were following in sequence: palming, blinking, sideways viewing, front and sideways viewing, diagonal viewing, rotational viewing, preliminary nose-tip gazing, near and distant viewing, concentrated gazing (trataka), and the acupressure point on the palm. This intervention was given 30 min/day for 5 days a week for up to 6 weeks under the guidance of a yoga instructor. The IOP levels were measured at baseline and after each week. While the baseline IOP levels were not significantly different between the two groups, at the end of 6 weeks, a significant reduction in IOP levels was noted for both eyes in the yoga group but not in the control group. Similar findings were reported by Dimitrova and Trenceva, 2017 in a nonrandomized comparative study. They divided 23 healthy adults into two groups, of which one performed yoga ocular exercises and the other as a control (Dimitrova and Trenceva, 2017). They measured IOP of the right eye only before and after the intervention. The ocular exercises were for 5 min and included palming or warming the eyes by rubbing the palms without putting pressure to the eyeballs, which was followed by slow movements of eyeballs in vertical, horizontal, and sideways directions. The results were a significant decrease in IOP levels in the exercise group and no significant changes in the control group. A recent study included 60 persons with type 2 diabetes mellitus who were examined for IOP changes following jyoti trataka, i.e. a form of continuous gazing (Ismail et al., 2021). The participants were randomized into two groups, a control group and a study group, in which jyoti trataka was given in a 55 min session daily for 1 month. The intervention included palming and eye movements followed by gazing at the flame of a candle placed at 4 feet distance at eye level. Among other changes, after 1 month, the IOP levels were significantly lower in the study group and were not changed in the control group. Another study examined the effects of ocular exercises on IOP and macular structure in 29 adults (Galina et al., 2020). The ocular exercises were similar to that in previous studies, including palming, eye rotation, and relaxation for 10 min. A significant reduction in IOP levels and an increase in the average retinal thickness of the macula were reported after eye exercises.

Intraocular pressure and pranayama

Alternate nostril yoga breathing is a form of yoga breathing technique or pranayama which, along with foot reflexology, was used in a study conducted on patients with ocular hypertension (Pandya et al., 2019). In this crossover study, 11 participants were included who performed either alternate nostril yoga breathing or foot reflexology for 5 min and which was alternated 2 weeks later. IOP was assessed before the task, after the task, and subsequently every 30 min for 2 h. Both alternate nostril breathing and foot reflexology resulted in a significant decrease in IOP levels for both eyes at all time points. A recent study was conducted on glaucomatous as well as healthy individuals to examine the effects of alternate nostril yoga breathing on IOP (Paidimarri et al., 2021). Forty-seven adults were included who were studied in three groups, a glaucoma group and a normal group that underwent the breathing exercise as well as a normal group that did not. In all groups, IOP was recorded at baseline, at 4 min after 10 cycles of alternate nostril yoga breathing and again after 10 min of rest. Analysis of variance showed no significant changes following breathing exercises in both healthy and glaucomatous persons implying no short-term immediate effects of alternate nostril yoga breathing on IOP. Longitudinal effects of pranayama were studied in another recent study which included 90 patients with POAG who were randomized into two groups, a pranayama group that practiced diaphragmatic breathing and alternate nostril breathing 30 min a day for 7 days per week for up to 6 months along with regular medication and a control group that was only on regular medication (Udenia et al., 2021). After the study period, the pranayama group showed reduced IOP levels compared to the control group, suggesting beneficial properties as a long-term adjuvant therapy.

Intraocular pressure and asana

Asana involves physical postures usually lasting for several seconds to minutes, depending on the experience of the practitioner, and is mostly included in a yoga practice session (Kala et al.,2021). Sirsasana or headstand pose was examined for its effects on IOP levels in a study involving 75 healthy individuals (Baskaran et al., 2006). IOP levels were recorded before, during, and after sirsasana posture in all individuals. The IOP levels rose significantly twice-fold during the posture compared to baseline in all age groups irrespective of the ocular biometry and ultrasound pachymetry. However, the elevated IOP levels returned to normal when the participants resumed sitting posture. Another study was on ten individuals with POAG and 10 normal healthy adults who practiced four common yoga postures, i.e. adhomukha svanasana, uttanasana, halasana, and viparita karani each for 2 min (Jasien et al., 2015). Their IOP levels increased significantly when they assumed the postures, which were not significantly different for glaucomatous and healthy eyes. Furthermore, the IOP levels fell to normal when the participants returned to normal sitting positions.

Intraocular pressure and meditation

A prospective study was conducted on 14 POAG and glaucoma suspect patients who were given the following interventions as daily life activities: “walking/cycling,” “resistance training,” “yoga/meditation,” and “emotional stress” (Gillmann et al., 2021). While the other three activities increased the IOP levels, meditation caused a decrease in the IOP levels; however, it was not significant.

Conclusion

Yoga practices were found to influence IOP levels in both healthy and clinical populations. Yoga postures were associated with an increase in IOP levels, whereas other yoga practices, i.e. eye exercises, pranayama, and meditation, reduced the IOP levels. Yoga-based eye exercises such as palming, trataka, and eye movement and relaxation reduced the IOP levels most persistently. These exercises cause the contraction and relaxation of ciliary muscles, which results in increased aqueous humor outflow, hence reduced IOP. Mental stress and anxiety are associated with increased cortisol levels, and since glaucoma patients are high steroid responders, the increased cortisol can lead to an increase in IOP (Marc and Stan, 2013). Yoga practices focus on increasing self-awareness, and especially Pranayama and meditation have been linked with reduced serum cortisol (Thirthalli et al., 2013) as well as reduced stress (Maheshkumar et al., 2022), anxiety (Cramer et al., 2018), and relaxed mental state (Deepeshwar et al., 2019). It is plausible that these stress-relieving properties of pranayama and meditation could aid in reduced IOP levels. Apart from these yoga practices, yoga postures or asanas showed an increase in IOP levels. These postures were head-down postures and showed a rapid increase in IOP immediately after assuming the postures. These inverted yoga poses might increase the pressure of episcleral veins and orbital veins into which aqueous humor is eventually drained, which has a direct relationship with IOP. It is notable that the rise in IOP during yoga postures is of concern for glaucoma patients as IOP remains the key risk factor in the development and progression of glaucomatous optic neuropathy; hence, inverted yoga postures should be avoided by these patients.

The present study reviewed studies on various yoga practices in patients and in healthy population for effects on IOP and concluded that most of the yoga practices other than inverted yoga postures could decrease IOP levels, therefore, has the potential to be an economic therapeutic aid to the system for patients with optic neuropathies such as glaucoma. These findings suggest that yoga may be a promising adjunctive therapy for the management of IOP and the prevention of conditions such as glaucoma. However, it is important to note that the evidence is still limited, and more research is needed to fully understand the mechanisms by which yoga may influence IOP and to determine the optimal yoga interventions for this purpose. Nonetheless, the potential benefits of yoga for reducing IOP suggest that it may be a valuable addition to traditional medical treatment approaches for individuals at risk of or with eye conditions related to elevated IOP levels.

However, future studies should aim to use larger sample sizes across communities and more rigorous study designs to provide more robust and reliable evidence on the relationship between yoga and IOP. Nonetheless, optimal care should be taken when using yoga practices as therapeutic means in patients with glaucoma and optical disorders. Furthermore, it is important to undergo proper clinical evaluation before starting a yoga therapy program for the management of diseases with elevated IOP levels.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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