Intraocular Pressure Fluctuation during Aerobic Exercise at Different Exercise Intensities

Few studies have examined the effects of different aerobic-exercise intensities on intraocular-pressure (TOP) changes. This may be important for eye diseases that are impacted by TOP or its fluctuation, including glaucoma, and diabetes that is complicated by diabetic retinopathy. We investigated the effects of low-, moderate-, and high-intensity exercise on TOP in healthy subjects. A submaximal cardiopulmonary exercise test was performed in 18 healthy male subjects, and the maximal oxygen uptake was calculated. The subjects then exercised for 20 min at 30%, 50%, and 70% .VO2 of maximal oxygen uptake, and their TOP was measured at rest and every 5 min during exercise. Oxygen uptake was monitored using an expiratory gas analyzer during exercise to maintain accurate exercise intensity and adjust exercise load. Oxygen uptake during exercise was significantly higher at all intensities from 5 to 20 min than at rest. TOP was significantly lower at 70% exercise intensity from 5 to 20 min than at rest. A negative correlation existed between TOP and .VO2. TOP remained unchanged during low- and moderate-intensity exercise but significantly declined during high-intensity exercise compared with that at rest. Although various factors, such as beta-blockers, are involved in TOP decline at rest, a different mechanism is involved in TOP decline during exercise.