A European study has recorded the first continuous telemetric measurements of intraocular pressure (IOP) during aerobic exercise in glaucoma patients. Researchers found that IOP rises with increased physical intensity and drops after exercise, suggesting a dose-dependent effect.
The study, conducted by researchers at the Otto-von-Guericke-University in Magdeburg, Germany, and the University Medical Center in Groningen, the Netherlands, was recently published in the British Journal of Ophthalmology.
Ten patients (6 male, 4 female) aged 67 to 79 years with open-angle glaucoma who previously had the eyemate-IO sensor (Implandata Ophthalmic Products) implanted during cataract surgery were recruited for this exploratory single-center clinical trial. Unlike traditional tonometry, the eyemate-IO sensor allows real-time telemetric IOP measurements that are unaffected by corneal properties or patient movement. The subjects 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.
Patients’ baseline IOP was 15.4±1.3 mmHg. With exercise, peak IOP (75 W) was 18.0±1.3 mmHg. Eight out of 10 participants showed IOP levels below baseline (14.4±1.0 mmHg) during the postexercise rest period (mean ΔIOP = –0.98±0.57 mmHg; 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.
Post-exercise 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. Other limitations reported by the authors 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. GP