Gonioscopy Assisted Transluminal Trabeculotomy (GATT)

When eye drops or laser are unable to adequately lower eye pressure, Gonioscopy Assisted Transluminal Trabeculotomy (GATT) can be considered. GATT may allow for eye pressure control with or without the use of glaucoma medications. For patients who qualify for the procedure, GATT provides an alternative to bleb-forming glaucoma surgeries (trabeculectomy, Xen) or tube shunts.

How does GATT work?

GATT cuts the first layer of the natural drain system (trabecular meshwork). This allows the fluid to leave the eye more easily, and lowers the eye pressure.

What are the steps of surgery?

The surgery is performed in the operating room under anesthesia. The eye is cleaned and numbing medication is applied. An instrument then opens the eyelids. Tiny incisions are made in the front of the eye, and a special lens is placed on the eye to visualize the eye’s natural drain. A small opening is made in the drain, through which a catheter (a wire the size of a strand of hair) is inserted. The catheter has a light at one end, allowing the surgeon to track its position. Once the catheter has reached the right position, the catheter is pulled and the drain is opened. The fluid can then leave the eye. The GATT procedure takes about 45 minutes, but will take longer if performed along with cataract surgery.

What will I feel during the surgery?

You may see bright lights during the surgery, but should not feel any pain. You will be discharged with a clear plastic shield with or without a patch over the operated eye. An adult will need to drive you home since you received sedating medications.

What happens to the eye after surgery?

Fluid leaves the eye through the large channel that is created in the eye’s natural drain. This lowers the eye pressure, and in some patients one or more glaucoma medications may be stopped after surgery.

How often will I be seen after surgery?

You will see your doctor the first day after surgery, about a week later, and a few weeks after that. Depending on how your eye heals, additional or fewer visits may be needed.

What eye drops will I use after surgery?

Most patients will be asked to use a steroid and antibiotic eye drops. The frequency of the taking the steroid eye drops depend on the amount of the eye inflammation.

Can I stop my glaucoma drops after surgery?

Your doctor will tell you which drops to continue using and how often at each visit depending on how your eye is doing. Sometimes patients are able to reduce the number of eye drops they are taking. Even if you are taking the same glaucoma medications after the procedure, the surgery is a success if your pressure is lower. The need for eye drops long-term after this treatment varies greatly and depends on your type of glaucoma and the rate at which it is progressing.

Will my vision improve right after surgery?

The first few days after surgery, vision may be blurry and even worse than it was before surgery. This will improve over 1-2 weeks, although it can sometimes take longer. The eye that was not operated on will not be affected, and may be depended on for vision during the recovery period (if it has vision).

What is the recovery time and what should I expect?

Depending on your job and your other eye, you should be able to return to work within a few days to a few weeks. Limitations in physical activities at work may be needed. After surgery, your eye may be sore, and it may feel like there is something in it, like an eyelash. The drops may burn when you put them in, and your eye may water or tear a lot. These symptoms are common but usually are mild, and improve for most people after 1-2 days. Tylenol (acetaminophen) is a good option unless you are unable to take this medication. If your eye has severe pain or sudden worsening pain or vision after surgery, please call our office or on call physician immediately.

Will I have any restrictions after surgery?

You will be given detailed instructions after your surgery that are specific to your eye’s needs. In general, the following guidelines apply:

The plastic shield should be worn while sleeping for 1 or more weeks after surgery to protect the eye.
While outside during the day, sunglasses should be worn to protect the eye from the sun and wind.
For the first few weeks, avoid strenuous activities (running, lifting more than 10 pounds), bending, rubbing the eye, wearing eye makeup, and swimming.
There are no restrictions in reading, watching TV, using your phone, tablet device, computer, etc but you may tire more easily during these activities.

What are the possible side effects of GATT surgery?

GATT is considered a relatively low risk surgery. Studies have shown that about 30% of patients have a small amount of blood in the front of the eye after GATT surgery. This usually resolves within 2 or 3 weeks and temporarily causes the vision to be blurry. A small percent of people experience an increase in eye pressure due to the blood. This is also temporary, and can be treated with glaucoma drops or may need another procedure. Other problems might be: infection, bleeding in the back part of the eye, need for additional surgery, and other eye surgery complications.

Will GATT cure my glaucoma?

The simple answer is no. Glaucoma is a chronic disease that requires constant monitoring and treatment. The GATT procedure will help to lower your eye pressure. However, it will not reverse any loss of vision that has already occurred.

What happens if GATT does not work?

Whether or not medications or an additional procedure will be needed after GATT depends on what is considered a “safe” pressure for your eye, how much your eye scars, the type of glaucoma you have, and more. After surgery, we will continue to monitor you closely so we can adjust therapy if needed.

For more information, please see:

American Academy of Ophthalmology Patient Information Website:

https://www.aao.org/eye-health/diseases/what-is-glaucoma

American Glaucoma Society Patient Information Website:

https://www.americanglaucomasociety.net/patients/patient-education