Peking Union Medical College Hospital ophthalmologist reply: Hello! The drugs like perilimine are carbonic anhydrase inhibitors, which mainly lower IOP by reducing the production of atrial aqueous class. Therefore, both open-angle glaucoma and closed-angle glaucoma are applicable. The description of these drugs emphasizes their primary use for open-angle glaucoma, because for closed-angle glaucoma, the primary treatment is still laser or surgery. Medications are generally only used as adjuvant or combination therapy for closed-angle glaucoma. I hope this answers your question.