Glaucoma - Surgery

Highlights	Risk Factors	Lifestyle Changes
Introduction	Diagnosis	Resources
Causes	Treatment	References
Symptoms	Medications
Outlook	Surgery

Surgery

If medications do not control eye pressure or if they create intolerable side effects, surgery may be necessary in a small percentage of people with chronic glaucoma. It may be particularly beneficial for patients with pseudoexfoliation glaucoma.

The standard procedures are usually one of the following:

Filtration surgery (trabeculectomy). This procedure opens the full thickness of the drainage area.
Laser trabeculoplasty. This procedure partially opens the drainage area. It does not reduce pressure to the extent of trabeculectomy but it has fewer adverse effects.

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African Americans may respond better to initial laser surgery than to conventional trabeculectomy while the opposite may be true in Caucasians. Some experts now recommend that, in most circumstances, African Americans should start with laser surgery and Caucasians who have no serious medical problems should have trabeculectomy first.

In addition, a number of experimental and less invasive procedures are under development.

Filtration Surgery (Trabeculectomy)

The Procedure. Filtration surgery has been used for more than 100 years with only minor modifications. It employs conventional surgical techniques known as full-thickness filtering surgery or guarded filtering surgery (trabeculectomy).

The surgeon creates a sclerostomy, a passage in the sclera (the white part of the eye) for draining excess eye fluid.
A flap is created that allows fluid to escape but which does not deflate the eyeball.
The surgeon may also remove a tiny piece of the iris (called an iridectomy) so that fluid can flow backward into the eye.
A small bubble called a bleb nearly always forms over the opening, which is a sign that fluid is draining out. Although surgeons aim for a thick bleb, which poses less risk than a thin one for later leakage, paradoxically the ideal operation would have no bleb at all.

The procedure has a high success rate. About 50% of patients no longer need medication after surgery. Thirty-five to 40% of those that still need medication have better control of their glaucoma. A new instrument called a trabectome has allowed for a less invasive type of trabulectomy surgery The trabectome procedure appears to be a safe and simple way to lower eye pressure. It can be performed before a traditional trabulectomy, if needed. . Results from a small study, presented at the 2005 meeting of the American Academy of Ophthalmology, showed that the new approach successfully reduced eye pressure in 90% of patients with open-angle glaucoma.