Trabeculectomy. Close-up of suturing the eye of a patient after a trabeculectomy, an operation to reduce pressure in the eye caused by glaucoma. The eye is held open by a metal retractor and a needle & forceps are seen stitching the thread. Glaucoma is caused by fluid build up in the eyeball. A trabeculectomy creates an alternative outlet for this fluid, thus reducing pressure. The mucous membrane covering the front of the eyeball (the conjunctiva) is opened and a half thickness of the white of the eye (the sclera) is cut and folded forward. A connection is made into the front chamber of the eye to act as a fluid outlet. The flap is sutured shut & conjunctiva replaced.