Posted 10.23.2018 | by AMRA

Glaucoma is a leading cause of blindness that affects 65 million people worldwide. It is caused by increased fluid buildup inside of the eye (intraocular pressure) that results in progressive damage to the optic nerve. Psychological stress is known to increase several glaucoma risk factors (oxidative stress, inflammation, glutamate toxicity, and vascular dysregulation) while simultaneously reducing several protective factors (neurotrophins and glial activity). This finding has led some to wonder whether stress reduction interventions might benefit glaucoma patients.

Dada et al. [Journal of Glaucoma] conducted a randomized, controlled study to test if a mindfulness-based intervention (MBI) could reduce intraocular pressure and affect psychological stress-related biomarkers as well as alter gene expression in glaucoma patients.

The researchers randomly assigned 90 patients (average age = 57 years; 55% male) with moderate-to-severe glaucoma to either a MBI or a wait-list control group. MBI participants engaged in daily hour-long teacher-led group sessions for 21 consecutive days. The sessions included 15 minutes of slow-breathing exercises followed by 45 minutes of mindfulness meditation. Attrition rate was 18% in the MBI group and 7% in the wait-list control group.

Intraocular pressure was assessed pre- and post-intervention, as were biomarkers of psychological stress (cortisol and β-endorphins), inflammation (IL-6 and TNF-α), oxidative stress (the imbalance between free radicals and antioxidants as measured by ROS and TAC), and a protein that protects nerve cells (BDNF). Whole blood RNA was assessed for post-intervention differences in gene expression, and participants completed the World Health Organization Quality of Life Questionnaire.

MBI participants showed a significant 6 mmHg reduction in intraocular pressure, while controls only decreased by about 1 mmHg. Seventy-five percent of the participants who completed the MBI reduced their pressure by over 25%. In evaluating quality of life, MBI participants recorded significant improvements while controls recorded little to no improvement.

Biological markers for stress (cortisol, β-endorphins) showed significant improvement for MBI participants, but remained essential unchanged for controls. One measure of inflammation (TNF-α) significantly decreased for MBI participants and significantly increased for controls. For MBI participants, levels of BDNF significantly increased and oxidative stress measures (ROS and TAC) significantly improved, but similar changes were not observed for controls.

With regard to gene expression, 109 genes differentiated MBI participants from controls. These included genes implicated in nerve cell maturation, cell death and survival, inflammation, glutamate toxicity, and ocular hypertension.

There were significant intercorrelations between intraocular pressure, all of the biomarkers, differential gene expression, and quality of life. For example, lower intraocular pressure was positively associated with quality of life, BDNF, TAC, β-endorphins and a variety of genes, but negatively associated with cortisol, IL-6, ROS, and certain other genes.

The results show initial promise for the adjunctive use of mindfulness-based interventions in the treatment of glaucoma. Mitigating stress by means of a daily mindfulness practice appears to play a role in reducing biological markers that indicate progression of glaucoma.

The results are limited by the absence of long-term follow-up or an active control. As this is the first study of the use of a MBI as an adjunctive treatment for glaucoma, the results require replication before more definitive statements can be made.

Reference:

Dada, T., Mittal, D., Mohanty, K., Faiq, M. A., Bhat, M. A., Yadav, R. K., . . . Dada, R. (2018). Mindfulness meditation reduces intraocular pressure, lowers stress biomarkers and modulates gene expression in glaucoma: A randomized controlled trial. Journal of Glaucoma.

[Link to abstract]