There are many types of glaucoma, such as primary angle-closure glaucoma, open-angle glaucoma, and normal-tension glaucoma. Once glaucoma is definitively diagnosed, medication can be used first to control intraocular pressure. If medications cannot control the pressure, surgery may be considered. However, generally, if it is early stage, and there is no damage to vision or visual field, with not very high intraocular pressure, medication can be considered first. If the intraocular pressure remains very high, medication fails to stabilize it, and there is a decline in vision or damage to the visual field, then surgery is needed.