Trabeculectomy is a surgical procedure which removes part of the trabeculum in the eye in order to relieve pressure caused by glaucoma. This is one of the best ways to relieve the dangerously high pressure in an eye with glaucoma. Usually trabeculectomy is done, when medication treatment for glaucoma has failed to reduce the pressure in the eyes enough to prevent damage to a person's eyesight. It is the most common surgical, non-laser procedure performed for glaucoma when the IOP is no longer controlled by eye drops, pills or laser trabeculoplasties.

Trabeculectomy procedure involves removing a small piece of the eyeball, right at the place where the cornea connects to the sclera i.e. the white part, and creates a flap to allow fluid in order to escape the anterior chamber without deflating the eye. The eye pressure is now reduced because the fluid can now drain with relative ease through the new opening into a reservoir underneath the conjunctiva, which comprises the surface of the eye and the fluid is then absorbed by the body.

After trabeculectomy procedure, the eye is covered by an eye patch and is protected by a plastic shield overnight. However, the results of the trabeculectomy depend on various factors and can vary greatly but the most common problem after a trabeculectomy is scarring of the opening. As per the general rule, approximately 70% of operated eyes will have satisfactory eye pressure and no need for medication required one year after surgery and if the eye drops are added, over 90% of eyes will have a satisfactory lowering of eye pressure. It is the most frequently used surgery to treat glaucoma since it provides excellent results.