In some patients with glaucoma, surgery is recommended. Glaucoma surgery improves the flow of fluid out of the eye, resulting in lower eye pressure.
A surgery called laser trabeculoplasty is often used to treat open-angle glaucoma. There are two types of trabeculoplasty surgery: argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT).
During ALT surgery, a laser makes tiny, evenly spaced burns in the trabecular meshwork. The laser does not create new drainage holes, but rather stimulates the drain to function more efficiently.
With SLT, a low level energy laser targets specific cells in the mesh-like drainage channels using very short applications of light. The treatment has been shown to lower eye pressure at rates comparable to ALT.
Even if laser trabeculoplasty is successful, most patients continue taking glaucoma medications after surgery. For many, this surgery is not a permanent solution. Nearly half who receive this surgery develop increased eye pressure again within five years. Many people who have had a successful laser trabeculoplasty have a repeat treatment.
Laser trabeculoplasty can also be used as a first line of treatment for patients who are unwilling or unable to use glaucoma eyedrops.
Laser iridotomy is recommended for treating people with closed-angle glaucoma and those with very narrow drainage angles. A laser creates a small hole about the size of a pinhead through the top part of the iris to improve the flow of aqueous fluid to the drainage angle.
When laser iridotomy is unable to stop an acute closed-angle glaucoma attack, or is not possible for other reasons, a peripheral iridectomy may be performed. Performed in an operating room, a small piece of the iris is removed, giving the aqueous fluid access to the drainage angle again. Because most cases of closed-angle glaucoma can be treated with glaucoma medications and laser iridotomy, peripheral iridectomy is rarely necessary.
In trabeculectomy, a small flap is made in the sclera (the outer white coating of your eye). A filtration bleb, or reservoir, is created under the conjunctiva — the thin, filmy membrane that covers the white part of your eye. Once created, the bleb looks like a bump or blister on the white part of the eye above the iris, but the upper eyelid usually covers it. The aqueous humor can now drain through the flap made in the sclera and collect in the bleb, where the fluid will be absorbed into blood vessels around the eye.
Eye pressure is effectively controlled in three out of four people who have trabeculectomy. Although regular follow-up visits with your doctor are still necessary, many patients no longer need to use eyedrops. If the new drainage channel closes or too much fluid begins to drain from the eye, additional surgery may be needed.
Aqueous shunt surgery
If trabeculectomy cannot be performed, aqueous shunt surgery is usually successful in lowering eye pressure.
An aqueous shunt is a small plastic tube or valve connected on one end to a reservoir (a roundish or oval plate). The shunt is an artificial drainage device and is implanted in the eye through a tiny incision. The shunt redirects aqueous humor to an area beneath the conjunctiva (the thin membrane that covers the inside of your eyelids and the white part of your eye). The fluid is then absorbed into the blood vessels. When healed, the reservoir is not easily seen unless you look downward and lift your eyelid.
Important things to remember about glaucoma:
There are a number of ways to treat glaucoma. While some people may experience side effects from glaucoma medications or glaucoma surgery, the risks of side effects should always be balanced with the greater risk of leaving glaucoma untreated and losing vision.
If you have glaucoma, preserving your vision requires strong teamwork between you and your doctor. Your doctor can prescribe treatment, but it’s important to do your part by following your treatment plan closely. Be sure to take your medications as prescribed and see your ophthalmologist regularly.