Related Experiment Video
Updated: Dec 29, 2025
09:03
Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye
Published on: June 20, 2015
10.3K
Acute effects of posture on intraocular pressure
Emily S Nelson1, Jerry G Myers1, Beth E Lewandowski1
1NASA Glenn Research Center, Cleveland, OH, United States of America.
Plos One
|February 7, 2020
Summary
Intraocular pressure (IOP) changes with body posture due to hydrostatic pressure. This study confirms hydrostatic pressure as the main driver of IOP shifts, with autoregulation playing a secondary role.
Area of Science:
- Ophthalmology
- Physiology
- Biomechanics
Background:
- Intraocular pressure (IOP) is influenced by body posture.
- Gravitational forces affect ocular physiology during postural changes.
- Understanding these effects is crucial for spaceflight and terrestrial activities.
Purpose of the Study:
- To analyze the relationship between intraocular pressure and postural changes.
- To determine the primary factors influencing posturally induced IOP variations.
- To provide insights for future research on ocular hemodynamics and aqueous humor dynamics.
Main Methods:
- Meta-analysis of 36 independent datasets from 30 articles.
- Inclusion of data from 821 subjects (≥1173 eyes).
- Analysis of IOP response across diverse initial and final postures.
Main Results:
- Intraocular pressure is accurately predicted by hydrostatic pressure at the eye level.
- The IOP response to posture is complex and nonlinear.
- Hydrostatic forcing, combined with autoregulation, explains posturally induced IOP changes.
Conclusions:
- Hydrostatic pressure is the dominant factor in postural IOP changes.
- Autoregulation contributes to IOP modulation based on hydrostatic effects.
- This comprehensive analysis aids future studies on ocular physiology and pressure regulation.
More Related Videos
08:55Translaminar Autonomous System Model for the Modulation of Intraocular and Intracranial Pressure in Human Donor Posterior Segments
Published on: April 24, 2020
3.4K
07:24Using Eye-tracking to Assess the Relative Importance of Visual and Vestibular Input to Subcortical Motion Processing in the Roll Plane
Published on: August 22, 2025
399
Related Concept Videos
01:27Open Angle Glaucoma: Treatment
900
In open-angle glaucoma, the iridocorneal angle remains open, but the trabecular meshwork becomes stiff, slowing down the outflow of aqueous humor. This causes a buildup of aqueous humor in the anterior chamber, leading to a sudden increase in intraocular pressure. The treatment for open-angle glaucoma focuses on reducing the elevated intraocular pressure by either decreasing the secretion of aqueous humor or increasing its outflow.
Drugs such as carbonic anhydrase inhibitors, α2- and...
Drugs such as carbonic anhydrase inhibitors, α2- and...
900
01:25Glaucoma: Overview
1.1K
Glaucoma is an eye condition characterized by increased intraocular pressure that damages the retina and optic nerve, leading to irreversible blindness if left untreated. The human eye has various components, including the cornea, iris, pupil, lens, and optic nerve. Aqueous humor is secreted by the epithelium of the ciliary body in the posterior chamber and flows through the trabecular meshwork and canal of Schlemm, maintaining normal intraocular pressure. The trabecular meshwork and the canal...
1.1K
01:28Angle Closure Glaucoma: Treatment
1.0K
Angle-closure glaucoma, or closed-angle glaucoma, is an eye condition where the iris bulges out and blocks the iridocorneal angle, resulting in a buildup of aqueous humor and increased intraocular pressure. Immediate medical attention is necessary due to the sudden onset of symptoms. The treatment for angle-closure glaucoma includes short-term and long-term approaches. Short-term treatment involves using eye drops like pilocarpine to lower intraocular pressure by increasing aqueous humor...
1.0K
01:17Accessory Structures of the Eye
3.2K
Optical perception, or vision, is an extraordinary sense dependent on converting light signals received via the ocular organs. These organs, known as eyes, are securely positioned within the bony cavities of the skull, called orbits. The orbits serve a dual purpose: a protective shield for the ocular globes and a stable attachment point for the soft ocular tissues. The eye's external protective mechanisms include the eyelids, which are edged with lashes that act as a barrier against foreign...
3.2K
01:20Muscles of the Eye
3.4K
The muscles of the eye are sophisticated structures that control eye movement and focus, allowing for the precise and rapid adjustments necessary for vision. The human eye is controlled by ten muscles — six extraocular muscles, three intraocular muscles, and one primary eyelid retractor muscle.
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and...
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and...
3.4K
01:30Alterations in Blood Pressure
1.8K
Alterations in blood pressure, such as hypertension (high blood pressure) and hypotension (low blood pressure), significantly affect human health. Understanding these conditions' classifications, causes, and symptoms is essential for effective management and treatment.
Hypertension (High blood pressure)
Hypertension occurs when blood pressure readings consistently exceed the normal range. It is diagnosed when systolic blood pressure (the top number, indicating pressure while the heart...
Hypertension (High blood pressure)
Hypertension occurs when blood pressure readings consistently exceed the normal range. It is diagnosed when systolic blood pressure (the top number, indicating pressure while the heart...
1.8K