A novel study published in the British Journal of Ophthalmology provides the first continuous telemetric measurements of intraocular pressure (IOP) in glaucoma patients during aerobic physical activity.
Using an implanted IOP microsensor, researchers demonstrated a dose-dependent rise in IOP with increased physical intensity and a subsequent drop in pressure postexercise.
Ten patients (6 male, 4 female) aged 67 to 79 years with open-angle glaucoma who previously had the eyemate-IO sensor implanted were recruited for this exploratory single-center clinical trial. They underwent a 10-minute ergometer cycling session with increasing power levels (0 to 75 W) in 25-W increments every 2 minutes. IOP was measured continuously via the sensor, while blood pressure (BP) and heart rate (HR) were monitored at each interval.
The eyemate-IO sensor, developed by Implandata Ophthalmic Products GmbH, allows real-time telemetric IOP measurements that are unaffected by corneal properties or patient movement, which are limitations of traditional tonometry.
Patients’ baseline IOP (0 W) was 15.4 ± 1.3 mm Hg. With exercise, peak IOP (75 W) was 18.0 ± 1.3 mm Hg. Eight out of 10 participants showed IOP levels below baseline (14.4 ± 1.0 mm Hg) during the postexercise rest period (mean ΔIOP = –0.98 ± 0.57 mm Hg; P=.12), though this difference was not statistically significant.
The researchers found that IOP was strongly correlated with systolic BP (R² = 0.997, P=.002) and heart rate (R² = 0.986, P=.007), but no significant correlation was found between IOP and diastolic BP (R² = 0.156, P=.6) These relationships were observed only during exercise. After exercise cessation, IOP dropped more rapidly than BP or HR, which suggested a transient systemic link rather than a causal dependence.
These findings suggest that IOP, systolic BP, and HR may be influenced by a common underlying factor—possibly sympathetic nervous system activation, the study authors explained. The increase in IOP during exertion may not necessarily be detrimental if it is offset by improved ocular perfusion pressure due to concurrent rises in BP. However, for glaucoma patients with impaired vascular autoregulation, such hemodynamic shifts could pose a risk to optic nerve health.
Postexercise IOP reductions were consistent with earlier studies that used traditional tonometry, though they lacked real-time resolution. The present study also highlighted the limitations of cornea-based sensors, which are more susceptible to biomechanical and external influences than intraocular sensors such as the eyemate-IO. Still, the intraocular sensors are only implanted in patients who undergo cataract surgery. Other limitations included the small study cohort and varied glaucoma stages, short exercise duration that may have missed complete IOP dynamics, and the lack of healthy controls.
The authors suggest that future studies should incorporate larger, more homogenous samples and longer observation periods to better understand the kinetics of IOP regulation during and after physical activity.
A full list of author disclosures is available in the published research.