**6. Collector channels**

The trabecular meshwork lies between Schwalbe´s line and the scleral spur, and it may be considered as two separate portions: (a) anterior part, which is composed of corneoscleral sheets and is not pigmented, meaning it is not visible gonioscopically; (b) posterior part, which is the primary site of aqueous outflow and is the pigmented trabecular meshwork composed of a syncytium of fibers. Gonioscopically, it has an irregular roughened pigmented surface. The amount and distribution of the pigment deposition varies considerably with age and race. At birth, it has no pigment, and develops color with age from light to dark brown, depending

The scleral spur is just posterior to the pigmented trabecular band, and it is the most anterior projection of the sclera internally. Gonioscopically, it is seen as a prominent white line between the ciliary body band and pigmented trabecular. It can be obscured by excessive pigment

The iris processes, thickenings of the posterior uveal meshwork, may be frequently seen crossing the scleral spur. They have the appearance of a variable number of fine and pigmented

The ciliary body band is the portion of ciliary body that is visible in the anterior chamber. The width of the band depends on the point of the iris insertion on the ciliary body. Gonioscopi‐ cally, it appears as a densely pigmented band, gray or dark-brown, posterior to the scleral spur

The corneoscleral meshwork is separated from the endothelium of Schlemm´s canal by a thin

The juxtacanalicular tissue is the outermost portion of the meshwork in contact with the inner wall of Schlemm`s canal. This tissue consists of a layer of connective tissue (types III, IV and V collagen, fibronectin) and ground substance (glycosaminoglycans and glycoproteins), and it is lined on either side by endothelium [31,32]. There is evidence that the juxtacanalicular tissue contains elastic fibers that provide support for Schlemm`s canal and that these fibers are

Schlemm`s canal is a 360-degree endothelial-lined channel that runs circumferentially around the globe. Generally, it has a single lumen, but occasionally it is like a plexus with multiple

The outer wall of Schlemm`s canal is a single layer of endothelium, without pores but with numerous large outlet channels and series of giant vacuoles, which form projections into the

lumen of Schlemm`s canal, possibly serving as a pathway for fluid moviment [33].

on the degree of pigment dispersion in the anterior chamber angle.

strands.

and anterior to the root of the iris.

10 Glaucoma - Basic and Clinical Aspects

**4. Juxtacanalicular tissue**

**5. Schlemm`s canal**

branches.

tissue, the juxtacanalicular tissue [29].

attached to the tendons of the ciliary muscle.

dispersion, and is not visible at variable degrees of narrow or occluded angles.

Schlemm`s canal drains into the episcleral and conjunctival veins by a complex system of vessels (collector channels or outflow channels). This system is composed of innumerous intrascleral aqueous vessels and aqueous veins of Ascher, which arise from the outer wall of Schlemm`s canal up to the episcleral and conjunctival veins. These collector vessels can run like a direct system, draining directly into the episcleral venous system or like an indirect system of more numerous, fine channels, forming an intrascleral plexus before draining into the episcleral venous system [34,35].
