Which structure is the major drain for aqueous humor outflow?

Which structure is the major drain for aqueous humor outflow?

• A. Trabecular meshwork (conventional, major drain)
• B. Ciliary body epithelium
• C. Iris sphincter
• D. Lens capsule

Answer: (A)

The major drainage path for aqueous humor is the conventional outflow through the trabecular meshwork into Schlemm's canal. Aqueous humor is produced by the ciliary body, flows into the anterior chamber, and then largely exits the eye by passing through the trabecular meshwork, which provides the main resistance and forms the primary route into Schlemm's canal and the venous system. This route accounts for the majority of outflow under normal conditions, so it is the principal drainage pathway. The ciliary body epithelium makes the aqueous humor, not its drainage. The iris sphincter controls pupil size, not outflow drainage. The lens capsule has no role in directing aqueous humor away from the eye.

The major drainage path for aqueous humor is the conventional outflow through the trabecular meshwork into Schlemm's canal. Aqueous humor is produced by the ciliary body, flows into the anterior chamber, and then largely exits the eye by passing through the trabecular meshwork, which provides the main resistance and forms the primary route into Schlemm's canal and the venous system. This route accounts for the majority of outflow under normal conditions, so it is the principal drainage pathway.

The ciliary body epithelium makes the aqueous humor, not its drainage. The iris sphincter controls pupil size, not outflow drainage. The lens capsule has no role in directing aqueous humor away from the eye.