Final answer:
The first-line therapy for open-angle glaucoma is prostaglandin analogs, which increase aqueous humor outflow. Alternative choices are beta-blockers and carbonic anhydrase inhibitors, which reduce aqueous production. Pilocarpine is another option that improves drainage by contracting the ciliary muscle.
Step-by-step explanation:
The first-line therapy for open-angle glaucoma when no contraindication exists is typically a class of drugs known as prostaglandin analogs. These medications work by increasing the outflow of aqueous humor from the eye, which helps to lower the intraocular pressure. Examples of prostaglandin analogs include latanoprost, bimatoprost, and travoprost. However, in the context of alternative first-line treatments, beta-blockers and carbonic anhydrase inhibitors can also be considered. Beta-blockers, such as timolol, decrease aqueous humor production, while carbonic anhydrase inhibitors, such as acetazolamide, decrease the formation of bicarbonate ions, leading to reduced fluid transport and aqueous humor formation.
Another important class of medications for treating open-angle glaucoma includes muscarinic agonists such as pilocarpine. Pilocarpine works by constricting the pupil and contracting the ciliary muscle, which helps to open the trabecular meshwork and enhance the drainage of aqueous humor, thus reducing intraocular pressure.