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Updated: Jun 26, 2026
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Trabecular Meshwork Response to Pressure Elevation in the Living Human Eye
Published on: June 20, 2015
Segmental Outflow and Trabecular Meshwork Stiffness in an Ocular Hypertensive Mouse Model
Cydney A Wong1,2, A Thomas Read1, Guorong Li3
1Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States.
Investigative Ophthalmology & Visual Science
|June 25, 2026
Summary
Dexamethasone (DEX) elevates intraocular pressure (IOP) in mice by altering trabecular meshwork (TM) flow, not by changing TM stiffness. Subtle structural changes in low-flow regions may contribute to steroid-induced glaucoma.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Cell Biology
Background:
- Elevated intraocular pressure (IOP) is a primary risk factor for primary open-angle glaucoma (POAG).
- Trabecular meshwork (TM) outflow is segmental, with distinct high-flow (HF) and low-flow (LF) regions.
- Understanding how ocular hypertension affects these regions is crucial for glaucoma research.
Purpose of the Study:
- To investigate the impact of ocular hypertension on segmental outflow in a dexamethasone (DEX)-induced mouse model.
- To compare trabecular meshwork (TM) stiffness between HF and LF regions in response to DEX treatment.
- To characterize TM structural and mechanical changes in steroid-induced ocular hypertension.
Main Methods:
- DEX or vehicle nanoparticles were injected into C57BL/6J mice over 4 weeks, with weekly IOP measurements.
- In vivo perfusion with fluorescent nanospheres assessed segmental flow patterns (HF, intermediate-flow, LF regions).
- Atomic force microscopy measured TM stiffness; immunofluorescence analyzed fibronectin and alpha-smooth muscle actin levels.
Main Results:
- DEX treatment significantly increased IOP by 33.3% and altered tracer distribution.
- No significant differences in TM stiffness were found between DEX-treated and control mice, or between HF and LF regions.
- Increased fibronectin in LF regions of DEX-treated eyes suggested subtle TM structural changes not detected by AFM.
Conclusions:
- DEX alters segmental flow distribution, potentially impacting cell contractility rather than extracellular matrix stiffness, leading to IOP elevation in young mice.
- These findings enhance our understanding of segmental outflow dynamics and TM mechanics in steroid-induced glaucoma.
- The study highlights potential mechanisms of IOP elevation relevant to glaucoma pathogenesis.
