Trabecular meshwork (TM) cells are the primary cell type that occupy and form the proximal portion of the conventional outflow pathway, the primary egress route for aqueous humor from the eye.

The trabecular meshwork is the spongy tissue located near the cornea through which aqueous humor flows out of the eye. The trabecular meshwork lies in the drainage angle (see video above), and 80 – 90 percent of aqueous humor makes its way into circulation via the trabecular meshwork and its associated structures.

The canal of Schlemm, or the scleral venous sinus, is a circular canal found within the posterior part of the corneoscleral junction. The function of Schlemm’s canal is to collect the aqueous humor from the anterior chamber of the eyeball and deliver it to the veins of the eyeball.

In closed-angle glaucoma, both the uveoscleral drain and the trabecular meshwork become blocked. Typically, this is caused by a damaged iris (colored part of the eye) blocking the outlet. Blockage of either of these outlets leads to an increase in pressure inside your eye.

connective tissue
The structure is composed of connective tissue beams and sheets or lamellae covered by TM cells. Three consecutive regions define the filtering portion of the TM: uveal meshwork, corneoscleral meshwork and juxtacanalicular region (JCT) also often called the cribriform region.

Schlemm’s canal is a circular lymphatic-like vessel in the eye. It collects aqueous humor from the anterior chamber and delivers it into the episcleral blood vessels. Canaloplasty may be used to widen it.

Definitions of Schlemm’s canal. a circular canal in the eye that drains aqueous humor from the anterior chamber of the eye into the anterior ciliary veins. synonyms: canal of Schlemm, sinus venosus sclerae. type of: canal, channel, duct, epithelial duct.

Angle-closure glaucoma occurs when the iris is positioned against the trabecular meshwork, blocking the flow of aqueous out of the eye and raising the intraocular pressure. When this occurs acutely, the pressure can be very high. The patient has pain and often nausea and vomiting.

…into a circular channel, the canal of Schlemm, from which the aqueous humour flows (by way of vessels called aqueous veins) into blood vessels. Blockage of the aqueous humour flow causes increased pressure in the posterior chamber, and this pressure is transmitted by way of the vitreous to the optic…

The trabecular meshwork lies in the drainage angle, and 80 – 90 percent of aqueous humor makes its way into circulation via the trabecular meshwork and its associated structures. Ophthalmologists and scientists believe that one particular part of the trabecular meshwork is the site of greatest resistance to aqueous humor outflow.

Schlemm’s canal. The canal is essentially an endothelium-lined tube, resembling that of a lymphatic vessel. On the inside of the canal, nearest to the aqueous humor, it is covered by the trabecular meshwork; this region makes the greatest contribution to outflow resistance of the aqueous humor. Conventionally,…

An obstruction in aqueous humor outflow plays an important role in the pathophysiology of glaucoma. As glaucoma is one of the leading causes of blindness in the general population, the importance of the canal of Schlemm and aqueous humor drainage becomes obvious.

The aqueous humor from the anterior chamber of the eye pours through these free spaces and reaches the inner surface of the canal of Schlemm. It is important to note that there is no open communication between the canal of Schlemm and the trabecular meshwork.