Abstract
Purpose: :
Elevated intraocular pressure (IOP) is one of many risk factors involved in the progression of Primary Open Angle Glaucoma (POAG) and clinically it remains the most easily controllable. However, POAG progresses asymptomatically over years and only 60 to 70% of patients comply with long term drug regimes. For over four decades researchers have examined the relationship between aerobic exercise and reduction of IOP. Exercise could be an important complementary chronic treatment; yet, for an exercise program to be considered a viable early intervention for those at risk it is important to identify the most effective combination of intensity and duration. To begin that investigation a meta-analysis was performed to compare the effect of these exercise parameters on IOP levels in a non-clinical population.
Methods: :
Searches were conducted via PubMed and Google scholar and 63 studies were obtained. Studies were excluded as per the requirements of the analysis or a lack of variance measures related to the mean change in IOP. The ten studies selected include sedentary or normally-active participants with normal baseline IOP (10 to 21 mmHg) who completed a single bout of mild (40% HR) to moderate (50 to 70% HR) aerobic exercise ranging from 2 to 60 minutes.
Results: :
There is a clear effect of exercise with a 1 to 5 mmHg reduction in IOP across conditions. Although we could not compute a global effect size because the 21 conditions did not each come from independent groups, we observe certain patterns in the results. First, the active and sedentary participants appear to benefit equally from exercise. Second, there is an almost twofold reduction in IOP from the mild to moderate intensity conditions. Finally, the duration of exercise does not appear to influence outcome for moderate intensity exercise while it does for the mild conditions.
Conclusions: :
The reduction in IOP as a result of exercise is within the range that is most useful to those at risk of POAG. Prescription of even a mild daily aerobic exercise regime could be an effective method to keep slightly elevated IOP levels within a normal range. The relationship between intensity and duration needs to be analyzed further in a longitudinal study that focuses on individuals at risk for POAG.
Keywords: intraocular pressure