Related Experiment Video
Updated: Jul 28, 2026
09:03
Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye
Published on: June 20, 2015
Pressure-induced syneretic response in rhesus monkey lenses
1Chemistry Department, Adelphi University, Garden City, New York 11530, USA.
Investigative Ophthalmology & Visual Science
|May 11, 1999
Summary
Decreasing hydrostatic pressure increases freezable water content in the lens, indicating a shift from bound to free water. This lens response, known as syneresis, may help prevent turbidity.
Area of Science:
- Ophthalmology
- Biophysics
- Cell Biology
Background:
- The lens maintains clarity through precise water content regulation.
- Understanding water dynamics is crucial for lens health and function.
Purpose of the Study:
- To determine how hydrostatic pressure affects the freezable and non-freezable water content within the ocular lens.
- To investigate the lens's response to varying external pressures.
Main Methods:
- Excised rhesus monkey lenses were exposed to different hydrostatic pressures (0.03, 1, and 2 atm).
- Differential scanning calorimetry (DSC) and thermogravimetric analysis were used to quantify water content.
- Lenses were analyzed for freezable and non-freezable water fractions under experimental pressures.
Main Results:
- Total lens water content remained stable across different applied pressures.
- Freezable water content significantly increased as applied pressure decreased in both nuclear and cortical sections.
- The ratio of freezable to non-freezable water decreased with increasing pressure.
Conclusions:
- The lens adjusts its osmotic pressure by altering water activity (converting free to bound water) in response to external hydrostatic pressure.
- Decreasing pressure induces syneresis, characterized by increased freezable water, which may prevent dilution-induced turbidity.
- This pressure-induced water regulation mechanism could be relevant to lens accommodation.
Related Concept Videos
01:27Open Angle Glaucoma: Treatment
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...
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...