Angle

• Schwalbe’s line
• Termination of DM and anterior border of trabecular meshwork
• Can be seen at corneal wedge
• Corresponds with the anatomical limbus
• Trabecular meshwork
• Non-pigmented portion (anterior)
• Pigmented portion (posterior): this part overlies Schlemm’s canal
• Corresponds with the corneoscleral limbus on the globe surface

• Scleral spur: appears as a white line anterior to the ciliary body.
• A fibrous protrusion of the sclera
• The longitudinal ciliary muscle (see below) inserts on the posterior scleral spur
• Ciliary body
• Visible as a concavity anterior to the iris root
• Comprises ciliary muscle and epithelium 
• Iris

Trabecular meshwork

• Uveal meshwork innermost: first layer for aqueous to cross
• Large intercellular spaces (70 microns)
• Low resistance to flow
• Corneoscleral meshwork middlemost
• Lamellar in structure
• Connective tissue covered by endothelium
• 35 microns (therefore medium resistance to flow)
• Cribiform (juxtacanalicular) meshwork outermost

• Loose extracellular matrix of collagen (type I mostly), elastic fibres and proteoglycans and trabecular cells within and lining passageways (these have phagocytic abilities to collect debris)

• Highest resistance to aqueous outflow (7 microns)

• Note: the TM comprises branching laminae with progressively decreasing pore size (hence resistance increases as you go deeper)

Schlemm’s canal

• Canal running in a continuous circle
• Lined by a single layer of non-fenestrated endothelium joined by tight junctions

• Aqueous drains from the TM to Schlemm’s canal via transcellular giant vacuoles (ie. they are not directly connected)

• Vacuoles are pressure-sensitive

• Drained by 25-30 collector channels that join the deep scleral plexus then the intrascleral plexus and 2-8 veins of Ascher

• Drain into intra/episcleral veins or directly into conjunctival veins
• Scleral spur sits posteriorly

• Described as the conventional outflow pathway: 70-90% of outflow