If medicated eyedrops are no longer sufficient to treat your glaucoma, your doctor may encourage you to consider glaucoma filtration surgery. Traditional glaucoma filtration surgery is called trabulectomy, which has been performed over the past thirty years. Trabulectomy involves making a small hole in the sclera to create a new opening for fluid to exit the eye.
A newer glaucoma treatment is called the Ex-PRESS mini glaucoma shunt (excessive pressure regulating shunt system). The Ex-PRESS is a simple method of filtration for open-angle glaucoma and can be implanted following cataract surgery. The Ex-PRESS device is made of stainless steel, is MRI compatible and has a spur-like extension on one end and an external disc at the other. More than 12,000 implantations have been performed worldwide, and Ex-PRESS provides effective long-term control of intraocular pressure (IOP). About the size of a grain of rice (3 mm), the shunt diverts a controlled amount of fluids through a small tube to the outside of the eye to maintain the correct intraocular pressure (IOP). The area of drainage is covered by the eyelid and is not visible.
Before the Surgery
No special preparation is needed before the surgery, but you may be asked to stop taking certain medications such as blood thinners (Coumadin, Plavix, Asprin, etc.).
During the Surgery
Ex-PRESS surgery can be done under local or general anesthesia. After anesthesia is administered, your surgeon will use an injection system to implant the shunt. A metal rod is fitted into the lumen of the shunt and is attached to the end of an injector. Your doctor will make a small flap in your sclera, (similar to the flap for a trabulectomy) and angle the shunt into the opening. The injector is depressed and the metal rod is placed into the eye. Your surgeon will then suture the opening.
The entire procedure takes about 40 minutes, and you can return to work anywhere from two to seven days after the procedure.
Most patients do not experience any pain after the surgery except for possibly a bit of discomfort from the dissolvable sutures. You will typically be seen by your doctor the day after, a week after and a month after your procedure. After that, quarterly appointments are recommended.
You will be given antibiotics, anti-inflammatory medications and sometimes laxatives to take after the surgery. It is important that you do not have any constipation or straining because this will increase eye pressure. You may even want to wear an eye shield at night. During the recovery period, you should avoid strenuous activities and sports as well as lifting, bending and straining. Most patients can return to work within about a week.
The Ex-PRESS shunt takes effect immediately, and eye pressure should stabilize within the first four weeks. The Ex-PRESS mini glaucoma shunt has a success of 90 percent and is effective, safe and often eliminates the need for glaucoma eye drops. Studies have found significantly lower IOP rates and fewer post-op complications in Ex-PRESS shunts compared to trabulectomy. Patients also experience a faster recovery of visual acuity.