Globe: Limbus

This higher magnification of the limbus shows the trabecular meshwork and the canal of Schlemm, also referred to as the scleral venous sinus.  These structures are responsible for draining aqueous humor from the anterior chamber.  Aqueous humor maintains intraocular pressure and provides nutrition for avascular ocular tissues.

This higher magnification of the limbus shows the trabecular meshwork and the canal of Schlemm, also referred to as the scleral venous sinus.  These structures are responsible for draining aqueous humor from the anterior chamber.  Aqueous humor maintains intraocular pressure and provides nutrition for avascular ocular tissues.

This higher magnification of the limbus shows the trabecular meshwork and the canal of Schlemm, also referred to as the scleral venous sinus.  These structures are responsible for draining aqueous humor from the anterior chamber.  Aqueous humor maintains intraocular pressure and provides nutrition for avascular ocular tissues.

The trabecular meshwork, located at the iridoscleral angle, consists of a network of connective tissue plates and cords lined by a specialized endothelium.  Aqueous humor in the anterior chamber percolates through the spaces to eventually reach the canal of Schlemm.

The canal of Schlemm is a ring-shaped vascular sinus that is located at the junction of the cornea and sclera. It is lined by endothelium and receives the aqueous humor from the trabecular meshwork. From the canal of Schlemm, fluid passes into veins of the sclera. This flow is facilitated by contraction of the ciliary muscle. Improper drainage of the aqueous humor results in increased intraocular pressure, a condition known as glaucoma, and can result in blindness.

Image taken of a slide from the University of Iowa collection.  Inset: Arizona Veterinary Diagnostic Laboratory.