The trabecular meshwork is a connective tissue meshwork of the sclera located around the circumference of the iris root and has a slit opening into Schlemm's canal that drains aqueous humor to the venous vessels. Trabecular meshwork cells (TMCs) play an active role in the flow of aqueous humor and this pathway is dependent on intraocular pressure. Injury or death of these cells has therefore been associated with the pathogenesis of open-angle glaucoma. CMTs also express receptors for neurotransmitters and neuropeptides, and respond to very low concentrations of a variety of vasoactive peptides and growth factors, allowing these cells to regulate trabecular permeability at multiple levels. TMC cultures provide a valuable tool to study the functional control of the trabecular meshwork, supporting the development of more effective strategies to treat glaucoma.