Overview of Trabeculectomy:
Trabeculectomy-sometimes referred to as filtration surgery-is the most commonly used glaucoma surgical procedure, usually performed when medical therapy does not succeed in controlling the intraocular pressure (IOP). It can be performed on patients with most types of glaucoma, but not all. For this procedure, you must have an intact, non-scarred conjunctiva, or a thin tissue that coats the surface of the eye wall. Trabeculectomy is also difficult to perform on eyes with any scarred tissue from previous surgeries. Trabeculectomy does not reverse any existing vision damage caused by glaucoma, but it can be very successful in preventing further vision loss.
How Trabeculectomy is Performed:
The main goal of trabeculectomy is to create a small hole by removing a piece of tissue in the drainage angle of the eye. The opening this creates is then covered with a flap of tissue from the sclera, or the “white part” of the eye, and the conjunctiva. This new opening allows clear fluid, or aqueous humor, to drain out of the eye, and thereby relieves the high IOP, the cause of nerve damage and vision loss. As fluid flows through the new drainage passage, it forms into a blister called a bleb, located where the sclera and iris meet, and which is then absorbed into the bloodstream.
What to Expect After Surgery:
Patients are not usually admitted to the hospital following the procedure, but are generally expected to have a checkup the next day with their eye specialist. Antibiotics will be applied to the eye or injected under the conjunctiva. The eyelid will be taped shut, and a hard eye shield will be placed over the eye to facilitate healing and protection. Patients will be instructed to avoid activity that may strain the eye following surgery, including bending, and lifting.
The recovery period for trabeculectomy is generally between six to eight weeks. The postoperative follow-up is especially important with this procedure, as the effectiveness depends greatly on the ability of the conjunctiva to heal. Mild discomfort following surgery is common, but severe pain may be a sign of complications. If you experience such pain, contact our practice immediately.
Risks and Side Effects:
As with all surgeries, some side effect may occur. Likewise, it is important to understand the risks of trabeculectomy, and to determine your suitability for the procedure. Drs. Alvi or Quraishi can help you decide when trabeculectomy is right for you.
A main risk of trabeculectomy is postoperative scarring of the new opening. Scarring in this area prevents fluid drainage, and interferes with the functioning of the bleb. Other possible side effects include bleeding in the eye, infection in the eye, and extremely low eye pressure causing blurred vision.
Trabeculectomy has about a 65-70% success rate in reducing visual field loss and lowering eye pressure, with an additional 20% success rate at achieving the goal IOP when combined with postoperative anti-glaucoma medications. Trabeculectomy is considered successful if it controls the IOP for a period of 7 to 8 years. If the first procedure fails, an additional trabeculectomy (or two) can be performed. Subsequent surgeries however, have a higher chance of failure than the original trabeculectomy.