In the article, Effect of Aerobic Exercise at Different Intensities on Intraocular Pressure in Young Males published in the November 2022 issue of Journal of Glaucoma, the researchers find that intense exercise has an IOP-lowering effect for 30 minutes after the activity.
There were 20 men average age of about 21 in the study.
For the 3 following tests, each lasting 25 minutes, subjects exercised at intensities of 50%, 70%, and 85% of peak power, respectively, and measurements were taken every 5 minutes.
They also measured blood pressure, blood lactate levels, and how hard the subjects thought they were exercising.
A significant reduction in IOP was observed during high-intensity exercise (85%) in both eyes (P<0.05). IOP began to decline 5–10 minutes after the start of the high-intensity sessions and continued to fall until the final post-session time point. This trend was not observed for low and medium exercise intensities.
The actual mechanism for this is not clear. They did not find correlations between heart rate and blood pressure, and IOP. They posit that CO2 might have a role.
It would have been interesting to see how long the IOP lowering lasted. However, they only tested IOP until 30 minutes after exercise. It will be interesting when the relationship is found because the IOP-lowering was significant: 29%.
We all recommend exercise for our patients. I was taught that it increased blood flow to the ONH to fight glaucomatous cell death. It also helps the cardiovascular system overall, which probably supports the health of the ONH. It may be good to recommend periodic high-intensity exercise a few times per week. Given the generally older population of those with glaucoma, be sure to have them do it with the blessing of their PCP.