Trabeculectomy is a glaucoma surgery that creates an alternative drainage pathway for fluid in the eye, thereby lowering the eye pressure.
Surgery is done in an outpatient operating room with a local anesthetic injection. The conjunctiva, the mucous membrane overlying the white part of the eye, is incised and dissected off the eye. A small trapdoor flap is then created in the sclera, the thicker white part of the eye underlying the conjunctiva. Beneath this flap a tiny hole is created to allow fluid to flow out of the eye. The trapdoor flap is then gently stitched down so that the fluid coming out of the eye is controlled. The conjunctiva is subsequently stitched back in place in a watertight fashion so the fluid from the eye collects beneath it, forming a small elevation called a bleb.
After surgery, frequent eye drops are needed to promote controlled healing. Careful postoperative monitoring is needed to prevent infection, scarring, or leaking from the incision. Often, the stitches holding the trapdoor flap in place will be selectively cut using a laser to permit adequate fluid flow beneath the flap.