High intraocular pressure is a very important clinical sign of glaucoma, and the type of IOP-lowering eye drops used varies according to different types of glaucoma. For example, in closed-angle glaucoma, the following types of IOP-lowering drops can be used: First, pupil constrictor type, such as Mao Guo Yunxin eye drops, which can pull open the atrial angle and increase the outflow of atrial fluid. Second, β-adrenergic receptor blocker class, such as timolol and carteolol eye drops, can reduce the production of atrial aqueous. Third, carbonic anhydrase inhibitors, such as brinzolamide eye drops, can reduce atrial aqueous production. Fourth, β-adrenergic agonist class, such as brimonidine tartrate eye drops, can reduce atrial aqueous production and at the same time increase atrial aqueous flow from the uveoscleral pathway. Hypertonic dehydrating agents, such as 20% mannitol injection, are also applied, but the maintenance time is relatively short, with an action time of only about six hours. For open-angle glaucoma, eye drops of the beta-adrenergic receptor blocker class, carbonic anhydrase inhibitor class, alpha-adrenergic agonist class, and prostaglandin derivatives are generally used.