Objective: The aim of this study was to synthesize the available evidence on the clinical efficacy of different relaxation exercises on intraocular pressure (IOP) reduction. Methods: A systemic search of PubMed, Embase, Cochrane CENTRAL, and Web of Science was undertaken from the earliest record to 10 April 2024. Peer-reviewed studies that reported on healthy individuals and glaucoma patients engaging in relaxation exercises for at least three weeks were included. The primary outcome was changes in IOP levels from baseline, before the commencement of relaxation exercises, to post-exercise. Our statistical analysis employed a random-effects model, with effect sizes reported using Hedges' g. Results: Twelve studies were included, totaling 764 eyes (mean participant age ranging from 21.07 to 69.50 years). Relaxation exercises significantly reduced IOP, with Hedges' g being -1.276 (95% CI: -1.674 to -0.879) and I2 = 84.4%. Separate subgroup analyses showed that breathing exercises (Hedges' g = -0.860, p < 0.0001), mindfulness-based stress reduction (MBSR) (Hedges' g = -1.79, p < 0.0001), and ocular exercises (Hedges' g = -0.974, p < 0.0001) were associated with reduced IOP levels. The reduction in IOP following the relaxation exercises was found to be associated with baseline IOP either greater than (Hedges' g = -1.473, p < 0.0001) or less than 21 mmHg (Hedges' g = -1.22, p < 0.0001). Furthermore, this effect persisted with follow-up durations of less than (Hedges' g = -1.161, p < 0.0001) and more than one month (Hedges' g = -1.324, p < 0.0001). Conclusions: The current meta-analysis indicates that relaxation exercises can significantly reduce IOP levels. Relaxation exercises are a potential class of novel treatments for glaucoma patients that deserve further evaluation.
Keywords: complementary therapy; glaucoma; mindfulness-based stress reduction; ocular hypertension; relaxation; yoga.