From the Research
The trabecular meshwork is a complex, fenestrated, three-dimensional structure composed of trabecular meshwork cells interdigitated into a multilayered organization within the extracellular matrix, playing a crucial role in regulating aqueous humor outflow and intraocular pressure. The trabecular meshwork is located at the angle where the cornea meets the iris in the eye, forming a critical component of the conventional aqueous humor outflow pathway. It consists of three distinct regions: the uveal meshwork (innermost layer), corneoscleral meshwork (middle layer), and juxtacanalicular tissue (outermost layer) which directly connects to Schlemm's canal 1.
Histologically, the trabecular meshwork is composed of beams or trabeculae made of collagen and elastin cores covered by flat endothelial-like trabecular meshwork cells. These beams are arranged in sheets with intervening spaces that become progressively smaller from the anterior chamber toward Schlemm's canal, creating a filter-like structure. The trabecular meshwork cells are metabolically active, containing numerous organelles including mitochondria, endoplasmic reticulum, and Golgi apparatus. They produce extracellular matrix components and possess phagocytic capabilities to clear debris from the aqueous humor.
Some key points about the anatomy and histology of the trabecular meshwork include:
- The juxtacanalicular region contains abundant extracellular matrix with glycosaminoglycans and proteoglycans, creating the greatest resistance to aqueous outflow 2.
- The trabecular meshwork's structure allows it to regulate intraocular pressure by controlling the outflow of aqueous humor from the eye.
- Dysfunction of the trabecular meshwork is a major contributor to the pathogenesis of open-angle glaucoma, a leading cause of irreversible blindness worldwide 3.
- Recent studies have highlighted the importance of the extracellular matrix in the trabecular meshwork, with changes in the ECM leading to increased outflow resistance and elevated intraocular pressure 4.
Overall, the trabecular meshwork plays a critical role in maintaining the health of the eye, and its dysfunction can have significant consequences for vision. The most recent and highest quality study 3 emphasizes the importance of understanding the anatomy and histology of the trabecular meshwork in order to develop effective treatments for glaucoma.