What is the mechanism of prostaglandin analogs for glaucoma management?

• A. Increase trabecular outflow
• B. Decrease production
• C. Decrease outflow
• D. Increase uveoscleral outflow

Answer: (D)

Prostaglandin analogs lower intraocular pressure mainly by increasing the outflow of aqueous humor through the uveoscleral pathway. They act on the tissues around the ciliary muscle to remodel the extracellular matrix and increase the permeability of the uveoscleral route, allowing more fluid to exit the eye. This mechanism targets outflow rather than production, which is why these drugs are particularly effective and are often chosen as first-line therapy.

They do not primarily decrease aqueous production (that’s more the role of beta-blockers or carbonic anhydrase inhibitors) and they do not mainly increase trabecular outflow. The key effect is enhanced uveoscleral drainage, which leads to the reduction in IOP.