What is the primary therapeutic action of Timolol maleate in managing primary open-angle glaucoma?

Timolol maleate is a non-selective beta-adrenergic antagonist commonly used in the management of primary open-angle glaucoma. Its primary therapeutic action is the reduction of aqueous humor production within the eye. By inhibiting the beta-adrenergic receptors in the ciliary body, Timolol decreases the secretion of aqueous humor, thereby lowering intraocular pressure, which is crucial in preventing damage to the optic nerve associated with glaucoma.

The mechanism of action directly addresses the overproduction of aqueous humor, which is a key factor in the pathophysiology of glaucoma. By managing intraocular pressure effectively, Timolol helps in preserving the visual function and preventing progression of the disease.

The other potential therapeutic actions listed do not reflect the established mechanism of Timolol's effect in glaucoma treatment. The drug does not induce pupil dilation; rather, pupil size is typically unchanged or can even become smaller with other classes of glaucoma medications. Timolol does not enhance ciliary muscle contraction, which pertains more to medications like pilocarpine that increase aqueous humor outflow. Similarly, Timolol does not enhance corneal sensitivity; instead, beta-blockers can reduce sensitivity in certain contexts. Hence, decreasing aqueous humor production is clearly the primary and