Trabeculectomy is currently the most classic anti-glaucoma procedure. This procedure is mainly used for the treatment of closed-angle glaucoma, or open-angle glaucoma that has failed with conservative treatment, and the cost of the procedure is about $2,000. The procedure involves making an artificial filter pillow at the corneoscleral rim, which can serve to control intraocular pressure. If the pressure inside the eye rises, some of the fluid can be released outward through this artificial channel, thus lowering the intraocular pressure, and the filter pillow is closed when the intraocular pressure is normal. This procedure is so effective that it remains, until now, one of the most effective procedures to prevent or control glaucoma. However, not all cases of glaucoma are suitable for this procedure, such as neovascular glaucoma or patients who have undergone multiple glaucoma surgeries, which are generally not recommended.