Reductions in intraocular pressure after acute aerobic exercise: a meta-analysis

Aerobic exercise is known to reduce elevated intraocular pressure (IOP), a primary risk factor for a disease of the eye known as primary open-angle glaucoma. Given the disparate nature of experimental protocols across the literature, an analysis of studies on the effect of acute aerobic exercise on IOP is necessary to verify the influence of participant characteristics, exercise intensity, and duration.

The electronic databases PubMed, Web of Science, and Embase were searched, producing 35 empirical studies for review. Ten studies producing 14 independent groups were chosen as per the criteria of the analysis.

Random effects model was used to produce subgroup analyses, and meta-regressions were used to verify the impact of group allocation, intensity, and duration on the interstudy variability of the effect size (ES). The outcome variable of postexercise change in IOP produced a significant effect of exercise, almost 2-fold greater for sedentary populations than for normally active populations (ES = -4.198; confidence interval, -5.151 to -3.245); ES = -2.340; confidence interval, -3.305 to 1.375, respectively). The significant effect of exercise on IOP is potentially mediated by group allocation. Intensity and duration do not contribute to the overall ES nor do they explain the difference between sedentary and normally active populations.

There is a robust effect of exercise on IOP for sedentary participants. However, the heterogeneity across study parameters, such as exercise protocol, IOP measurement, and participant selection, prohibited the inclusion of studies in this analysis that may have influenced the results. The current analysis makes clear the need for standardization of protocol across this field of research.