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 mechanisms 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.
The extracellular components include a complex matrix composed primarily of collagen (types I, III, IV, and VI), elastin, fibronectin, laminin, glycosaminoglycans (particularly hyaluronic acid), and proteoglycans 2, 3. This extracellular matrix forms a filtration system with progressively finer meshwork from the anterior to posterior regions. The balance between production and degradation of these extracellular components is crucial for maintaining proper outflow facility. Matrix metalloproteinases (MMPs) produced by trabecular meshwork cells help regulate this balance by degrading extracellular matrix components.
Some key points to consider about the trabecular meshwork include:
- The trabecular meshwork is a complex, fenestrated, three-dimensional structure composed of trabecular meshwork cells interdigitated into a multilayered organization within the extracellular matrix 1
- The extracellular matrix of the trabecular meshwork is dynamic, undergoing constant turnover and remodeling 3
- Dysfunction in either the cellular or extracellular components can lead to increased resistance to aqueous outflow, potentially resulting in elevated intraocular pressure and glaucoma 4
- Recent advancements in three-dimensional cell culture and tissue engineering have shown promise in reducing reliance on animal experimentation in certain aspects of glaucoma research 4