Trabecular meshwork and Schlemm’s canal (TM and SC)

The trabecular meshwork (TM) and Schlemm’s canal (SC) form the primary conventional pathway for aqueous humor outflow in the anterior chamber angle of the eye, regulating intraocular pressure (IOP) by draining fluid produced by the ciliary body into the bloodstream via collector channels. The TM is a spongy, multi-layered tissue structure—uveal, corneoscleral, and juxtacanalicular (JCT)—composed of extracellular matrix (ECM) beams covered by trabecular cells that perform phagocytic clearance of debris and dynamic ECM remodeling in response to mechanical stretch or cytokines like TGF-β2. The JCT region, adjacent to SC's endothelial lining, generates most outflow resistance through its loose ECM and connections to SC cells, which feature giant vacuoles and pores for fluid transit. Dysfunction, such as ECM accumulation, cell loss, or reduced phagocytic activity, impairs drainage, elevates IOP, and drives open-angle glaucoma pathogenesis, leading to optic nerve damage and vision loss. Therapeutic strategies target this pathway via minimally invasive glaucoma surgery (MIGS), including TM stents, goniotomy, or laser trabeculoplasty to enhance outflow, though pharmacological agents primarily act upstream by reducing aqueous production rather than directly modulating TM/SC.

Other names

aqueous humor outflow pathwaysconventional outflow pathwayiridocorneal angle drainage structures