Glaucoma Surgery

Doctors often recommend laser surgery before incisional surgery, unless the eye pressure is very high or the optic nerve is badly damaged. During laser surgery, a focused beam of light is used to treat the eye’s trabecular meshwork (the eye’s drainage system). This helps increase the flow of fluid out of the eye.

In contrast, incisional surgery (also called filtering surgery) involves creating a drainage hole with the use of a small surgical tool. This new opening allows the intraocular fluid to bypass the clogged drainage canals and flow out of this new, artificial drainage canal.

When laser surgery does not successfully lower eye pressure, or the pressure begins to rise again, the doctor may recommend incisional surgery. Occasionally, glaucoma surgery may have to be repeated especially if excessive scarring cannot be prevented or after long periods of time.

Conventional surgeries for glaucoma include trabeculectomy or aqueous shunts (see below). While they can be more effective at lowering eye pressure and preventing progression of glaucoma, they also have more potential complications.

In this procedure, a tiny opening is made in the sclera (the white part of the eye) with a small surgical instrument. This new opening allows the intraocular fluid to bypass the clogged drainage canals and directly flow out of this new opening. Special medications (“antifibrotics”) may be used to prevent scarring and closure of the new opening. The opening is covered by conjunctiva creating a bleb on the sclera. This procedure requires stitches and the recovery period is usually a few weeks.

Trabeculectomy, still considered the gold standard in glaucoma surgery, involves creating a new pathway for the eye to drain fluid. First, an eye surgeon creates a flap in the sclera — the white part of the eye — underneath the upper eyelid to allow fluid to drain. This drainage area is bounded by the outermost covering of the eye (the conjunctiva). By carefully managing the healing process with frequent office visits over several weeks after surgery, surgeons may lower eye pressure to the desired level.

During aqueous shunt surgery, a tiny tube is implanted that drains fluid out of the eye. Like trabeculectomy, this conventional surgery also requires stitches and the recovery period is usually a few weeks.

Minimally Invasive Glaucoma Surgery (MIGS) procedures include microsurgical instruments and devices and smaller incisions that manipulate the eye tissues less and therefore reduce the risk of complications. The increased safety of these surgeries is traded for reduced effectiveness.