Related Experiment Videos
Intraocular pressure, ocular pulse pressure, and body position
American Journal of Optometry and Physiological Optics
|January 1, 1985
Summary
Intraocular pressure (IOP) is higher when lying down compared to sitting. Clinicians should consider this positional change, as it may reveal elevated IOP in patients with borderline measurements, potentially aiding in diagnosing carotid artery stenosis.
Area of Science:
- Ophthalmology
- Biomedical Engineering
Background:
- Intraocular pressure (IOP) measurement is crucial for diagnosing and managing glaucoma.
- Positional changes can affect IOP readings, but this is not always considered in routine clinical practice.
Purpose of the Study:
- To compare intraocular pressure (IOP) measurements in sitting versus supine positions using the Digilab Pneuma-tonometer.
- To assess the utility of the Pneuma-tonometer for measuring ocular pulse pressure and its potential diagnostic value.
Main Methods:
- Intraocular pressures were measured in both sitting and supine positions using the Digilab Pneuma-tonometer.
- IOP measurements in the sitting position were also compared with those obtained using the Goldmann applanation tonometer.
- Ocular pulse pressure amplitude was measured using the continuous recording capability of the Pneuma-tonometer.
Main Results:
- Mean IOP was significantly higher in the supine position (17.03 mm Hg) compared to the sitting position (12.90 mm Hg).
- IOP measurements from the Pneuma-tonometer in the sitting position closely correlated with Goldmann applanation tonometer readings (13.42 mm Hg).
- The mean ocular pulse pressure amplitude was measured at 1.77 mm Hg.
Conclusions:
- Clinicians should be aware that IOP can be significantly elevated in the supine position, potentially unmasking glaucoma in patients with borderline sitting IOPs.
- The Pneuma-tonometer's ability to measure ocular pulse pressure may offer a novel approach for detecting carotid artery stenosis.