Which of the following best describes the mechanism of rho-kinase inhibitors in glaucoma management?

• A. Decreases outflow and increases EVP.
• B. Increases trabecular outflow, reduces aqueous humor production, and lowers EVP.
• C. Solely reduces aqueous humor production.
• D. Inhibits ciliary body cAMP.

Answer: (B)

Rho-kinase inhibitors lower intraocular pressure mainly by increasing trabecular outflow through the conventional drainage pathway. They do this by inhibiting rho-kinase, which relaxes the actin cytoskeleton in the trabecular meshwork and Schlemm’s canal, reducing resistance to outflow. In addition, they can modestly reduce aqueous humor production by relaxing the ciliary body and may lower episcleral venous pressure through vasodilation of ocular vessels. This combination—more outflow, plus some reduction in production and EVP—best matches what these drugs do in glaucoma management. The other options misstate the primary effect or omit the additional, albeit smaller, actions.