Aqueous and Aqueous Outflow Tract

The anterior chamber has a volume of about 0.15-0.2 ml. Aqueous humor is produced at estimated 1.5 microliters/minute with a diurnal variation. The anterior chamber is bordered anteriorly by the corneal endothelium, posteriorly by the iris and lens (over the pupil) and peripherally by the trabecular meshwork, ciliary body face and scleral spur. The anterior chamber is shallower in women than men. It is shallower in hyperopes than others. The anterior chamber is shallower in older patients. The average depth is about 3.5 mm in males.

Gonioscopically one encounters all of the structures lining the lens and the classic landmarks moving anterior to posterior are: 1. Schwalbe's line (termination of Descemet's membrane); it appears as a white line in the gonioscopic view. See diagram 2. The trabecular meshwork, which is tan and characteristically trabeculated, extends to the iris. Underneath the trabecular meshwork one may see a white band which is the scleral spur. The trabecular meshwork empties into Schlemm's canal which is a venous channel in the internal scleral sulcus. The canal forms a ring 36 mm in circumference. Multiple collector vessels arise from the canal and join the intrascleral venous plexus and eventually drain into the aqueous veins.