When medicated eye drops and laser surgery do not remedy intraocular pressure (IOP), your doctor may recommend conventional glaucoma surgery. The most common surgical option is trabeculectomy, also called filtration surgery. During the procedure, your surgeon will create a tiny opening in the sclera (the white part of the eye) covered by a thin trapdoor. The excess aqueous humor (the clear fluid between your eye’s lens and cornea) drains through the trapdoor to a small reservoir just under the eye surface, hidden by the eyelid. This will lower intraocular pressure and slow the effects of glaucoma.
About half of all trabeculectomy patients do not require glaucoma medication for a considerable amount of time after surgery. While effective at reducing IOP, this procedure is not considered a cure, and people can still experience vision loss even after surgery. Vision loss usually happens if the procedure fails which happens when your body heals too aggressively and closes the hole that the surgeon created. It’s important to work with your doctor to create a treatment plan and follow up schedule that is right for you.
What to Expect
Most trabeculectomy procedures are done at outpatient surgery centers with minimal prep. Some discomfort is normal after surgery, and temporary side effects like blurry vision and sensitivity to light are common. Your doctor will prescribe antibiotics and corticosteroids (anti-inflammatory eye drops) that you will use for a significant length of time after the procedure.
Ex-PRESS Glaucoma Shunt
If medicated drops are insufficient at lowering your intraocular pressure (IOP), your doctor may suggest glaucoma filtration surgery. The Ex-PRESS glaucoma shunt is a newer procedure, and an alternative to a larger silicone tube shunt or a trabeculectomy. About the size of a grain of rice, the shunt is a simple method of filtration for open-angle glaucoma and lowers IOP by routing aqueous humor from the anterior chamber of the eye. The area of drainage is covered by the eyelid and is not visible. The Ex-PRESS shunt procedure is a variation of a trabeculectomy procedure in which the shunt device creates an opening that your body has more difficulty scarring. This leads to a lower failure rate.
The Ex-PRESS shunt takes effect immediately, and eye pressure should stabilize within the first four weeks. Studies have found fewer post-op complications with Ex-PRESS shunts compared to trabeculectomy, and patients experience a faster recovery of visual acuity.
What to Expect
Your surgeon will go over your medications and may advise you to stop taking certain prescriptions before the procedure. Ex-PRESS shunt surgery can be done under local or general anesthesia. After anesthesia is administered, your surgeon will use an injection system to implant the shunt. The entire procedure takes about 45 minutes, and you can generally return to work anywhere from 1-2 weeks after the procedure. You will be given antibiotics and anti-inflammatory medications to take for several weeks after the procedure. During the recovery period, you should avoid strenuous activities and sports as well as lifting, bending and straining.
Glaucoma Drainage Devices
If trabeculectomy is not effective or your eyes have extensive scarring from previous surgeries, your doctor may recommend a tube shunt procedure called a glaucoma drainage device (GDD). These devices are designed to route excess fluid from the anterior chamber of the eye to an exterior reservoir using a silicone tube. The GDD is a plate that is hidden under the upper eyelid and is attached to the anterior chamber of the eye using a small silicone tube that penetrates into the eye through a very small hole in the sclera. Although glaucoma drainage devices are extremely effective at controlling internal ocular pressure and have a low risk of surgical failure, many patients still use some drops to help control the pressure.
What to Expect
Glaucoma drainage device surgery is typically done using light sedation in addition to medicine that anesthetizes the entire eye, with the entire procedure taking less than an hour. You will experience some redness and swelling after surgery, and your eyelid may droop a bit. This will go away after a few weeks. Most patients take a week or two off work to heal, and during the recovery period you should avoid straining and significant physical activity.