From the Research
The normal structure of the trabecular meshwork is a complex, fenestrated, three-dimensional structure composed of trabecular meshwork cells interdigitated into a multilayered organization within the extracellular matrix. The trabecular meshwork is a specialized tissue located at the junction where the cornea meets the sclera (limbus) in the eye, forming a critical part of the conventional aqueous humor outflow pathway. It consists of a series of interconnected beams or trabeculae made of collagen and elastic fibers, covered by trabecular cells 1. These beams form a mesh-like structure with spaces between them that gradually decrease in size as they approach Schlemm's canal. The primary function of the trabecular meshwork is to regulate intraocular pressure by controlling the outflow of aqueous humor from the anterior chamber of the eye. As aqueous humor passes through the increasingly narrow spaces of the trabecular meshwork, it encounters resistance, which helps maintain proper eye pressure.
The trabecular cells actively participate in this regulation by phagocytosing debris that might obstruct the outflow pathway and by modifying the extracellular matrix to adjust outflow resistance 2. Additionally, these cells respond to pressure changes and can alter their shape and contractility to further regulate fluid flow. The extracellular matrix in the trabecular meshwork plays a crucial role in regulating aqueous humor outflow, with the juxtacanalicular region and the inner wall basement membrane of Schlemm's canal being key areas of resistance 2. Dysfunction of the trabecular meshwork, such as increased resistance to outflow, is the primary cause of elevated intraocular pressure in open-angle glaucoma, highlighting its importance in ocular health. Recent studies have also highlighted the importance of understanding the trabecular meshwork's structure and function in the development of glaucoma, with advancements in three-dimensional cell culture and tissue engineering showing promise in reducing reliance on animal experimentation in glaucoma research 3.
Key aspects of the trabecular meshwork's structure and function include:
- A complex, fenestrated, three-dimensional structure composed of trabecular meshwork cells and extracellular matrix
- Interconnected beams or trabeculae made of collagen and elastic fibers, covered by trabecular cells
- A mesh-like structure with spaces between the beams that gradually decrease in size as they approach Schlemm's canal
- Regulation of intraocular pressure by controlling the outflow of aqueous humor from the anterior chamber of the eye
- Active participation of trabecular cells in regulating outflow resistance through phagocytosis and modification of the extracellular matrix. The most recent and highest quality study on this topic is from 2023, which provides an overview of current glaucomatous trabecular meshwork models, highlighting the importance of understanding the trabecular meshwork's structure and function in the development of glaucoma 3.