GATT Procedure

Gonioscopy-Assisted Transluminal Trabeculotomy

The GATT procedure was developed at the Glaucoma Associates of Texas in Dallas, TX. Since its inception, the doctors at Glaucoma Associates have performed thousands of this surgery successfully, more than all surgeons combined world-wide. The doctors have spoken extensively about GATT, nationally and internationally, and other doctors from around the world have come to Dallas, TX to observe and learn how to perform GATT by the doctors at Glaucoma Associates of Texas. 

What is GATT?

GATT (Gonioscopy-Assisted Transluminal Trabeculotomy) is a minimally invasive surgical treatment for the management of open angle glaucomas and is a modification of a glaucoma surgery (trabeculotomy) that has been around for over 50 years.  Trabeculotomy has a proven history of being safe and effective for the treatment of open angle glaucoma.  
How is GATT performed?

The GATT procedure is performed via micro-incisions in the cornea. An incision about 1.0 mm in size is made in the periphery of your cornea through which the surgery is completed. After entering the eye, the surgical procedure involves cutting through the trabecular meshwork, cannulating Schlemm’s canal 360°, and unroofing Schlemm’s canal.

One major advantage of this procedure is that it is able to access the entire natural drainage system and open in 360°, rather than targeting only a small portion of the drainage system. It is believed that opening the whole drainage system gives the best chance of the procedure working and adequate lowering the intraocular pressure.

 A second advantage of this procedure is that it does not involve opening up the conjunctival tissues to access Schlemm’s canal. Therefore, if further surgery is needed, there is less scar tissue and subsequent surgeries have a significantly higher rate of success. 

Who is a good candidate for GATT?

GATT is indicated for the surgical treatment of open angle glaucomas in both adults and children. However, in contrast to other “angle surgeries”, some forms of closed-angle glaucoma may also benefit.
How does it work?

GATT reduces IOP by restoring the trabeculo-canalicular outflow pathway. It increases the flow of aqueous humor from the anterior chamber, directly into and around Schlemm’s canal, and out through the collector channels. This procedure does not create a ‘bleb’ on the surface of the eye as fluid is routed through normal physiological pathways.

For more details, please read the GATT article in Ophthalmology times.

What is involved with the GATT procedure?

When you and your doctor make a decision to proceed with GATT, you will meet with our preoperative scheduling nurse who will give you detailed instructions on how to prepare yourself for your upcoming surgery and what is involved in getting to the operative room for the procedure. See Preoperative instructions for more information.

This is an outpatient procedure performed in an ambulatory surgery center. The surgery itself takes less than one hour in most cases. The surgery is usually done under local anesthesia with intravenous sedation. Sometimes, this surgery is combined with other surgeries, often with cataract surgery.

After surgery, the eye generally is covered by an eye patch and protected by a plastic shield overnight. On the morning following the surgery, it is removed and the eye is examined by your ophthalmologist. Eye drops are then prescribed to prevent infection, and reduce inflammation. For more details, please see postoperative instructions.

For several weeks following the surgery, your ophthalmologist will observe your eye closely and examine you frequently. It may take up to 12 weeks after your surgery for the healing to be complete. During this time it is not unusual for your intraocular pressure, as well as vision to fluctuate. You will be ready to change your glasses prescription at around 6-8 weeks after surgery.

Please contact the Glaucoma Associates of Texas if you have questions about this treatment for glaucoma.