From the Research
The trabecular meshwork is composed of both cellular and extracellular components, including trabecular meshwork cells and a complex extracellular matrix, which work together to regulate aqueous humor outflow in the eye. The cellular components include trabecular meshwork cells, which are specialized endothelial-like cells that maintain the extracellular matrix and respond to pressure changes through mechanosensing 1. These cells possess contractile properties and can alter the resistance to aqueous outflow. Juxtacanalicular cells are another important cellular component, located in the region adjacent to Schlemm's canal, where they play a critical role in regulating outflow resistance.
The extracellular components include a complex matrix composed primarily of:
- Collagen (types I, III, IV, and VI)
- Elastin fibers that provide structural support and elasticity
- Glycosaminoglycans (particularly hyaluronic acid and chondroitin sulfate) that regulate fluid movement
- Fibronectin that facilitates cell adhesion
- Laminin that helps maintain tissue architecture This extracellular matrix undergoes constant remodeling by matrix metalloproteinases produced by trabecular meshwork cells 2.
The balance between cellular activity and extracellular matrix composition is crucial for maintaining proper intraocular pressure, with dysfunction in this system potentially leading to conditions like glaucoma 3. According to the most recent study 1, the interplay between cells and their extracellular matrix milieu is essential for regulating aqueous humor outflow resistance, and dysfunction in this system can lead to increased outflow resistance and elevated intraocular pressure.