Assessment of the effect of physical activity on intraocular pressure using a novel implanted telemetric pressure sensor.

Abstract

Due to technical limitations of commonly used tonometry devices, the effects of physical exercise on intraocular pressure (IOP) have never been studied during exercise. This study continuously monitored IOP variations in patients with glaucoma during physical exercise using an implanted IOP microsensor. In total, 10 participants (six male and four female) with open-angle glaucoma (age range: 67-79), previously implanted with an IOP sensor, were included. We monitored IOP telemetrically during a 10 min session on a bicycle ergometer with a stepwise power increase from 0 to 75 W, in 25 W increments, at 2 min intervals. We also recorded IOP during the 2 min resting period after the exercise compared with resting baseline before exercise. The average IOP increased from 15.4±1.3 mm Hg at rest to 18.0±1.3 mm Hg at 75 W and returned to 14.4±1.0 mm Hg during the resting period after exercise. During the resting period after the activity, average IOP reduced below baseline in 8 out of 10 patients (ΔIOP=-0.98±0.57 mm Hg, p=0.12). Both systolic blood pressure and heart rate were highly correlated with IOP during the exercise (R^²=0.997, p=0.002 and R^²=0.986, p=0.007, respectively). In our study, IOP, heart rate and blood pressure increased and decreased with physical intensity, suggesting these parameters are closely linked and potentially driven by a common mechanism during aerobic exercise. Further studies with larger patient groups are warranted to better understand the mechanisms involved.