Laser Surgeries Can Help Treat Glaucoma
When ophthalmologists diagnose glaucoma early, they can offer a wider range of treatment options to control the disease and slow its progress. However, in advanced stages of glaucoma, fewer treatments options are available and patients may need to undergo surgery. Some surgical options for the treatment of glaucoma include the placement of a shunt or implant to allow fluid to drain from the eye, and the creation of an artificial drainage hole through a procedure called a trabeculectomy.
Before ophthalmologists recommend more invasive surgeries, they typically try laser treatments, since these procedures can be done on an outpatient basis and allow people to return to their daily activities almost immediately.
Primary Types of Laser Surgery
The laser surgery options for treating glaucoma largely depend on the type of glaucoma the patient has. One form of the disease is angle-closure glaucoma, which occurs when the angle between the eye’s iris and cornea becomes blocked, preventing fluid from draining out of the eye. The closed angle causes intraocular pressure to build quickly. Patients with angle-closure glaucoma and people with a narrow angle who haven’t yet developed the disease can opt for laser peripheral iridotomy. In this procedure, the ophthalmologist creates a small hole in the iris, which makes it possible for fluid to drain and provides immediate pressure relief.
For patients with primary open-angle glaucoma, the most common form of the disease, laser peripheral iridotomy is not appropriate. In primary open-angle glaucoma, the angle between the iris and cornea remains open, yet the eye’s trabecular meshwork — its fluid drainage system — fails to function properly. Patients with primary open-angle glaucoma may undergo argon laser trabeculoplasty, which uses a laser beam to unclog the trabecular meshwork so it drains fluid effectively. Often, the ophthalmologist performs the procedure over the course of two sessions, in order to prevent over-correction, which can reduce intraocular pressure too much. Argon laser trabeculoplasty helps approximately 75 percent of patients who undergo it, according to the Glaucoma Research Foundation.
When this option fails, patients may be a candidate for selective laser trabeculoplasty, which identifies specific cells for treatment in the eye’s trabecular meshwork. In this technique, an ophthalmologist uses a laser with minimal heat absorption, sometimes called a cold laser, to minimize inflammation and scarring of surrounding tissue. The treatment can be repeated without increased risk. Selective laser trabeculoplasty is similar to micropulse laser trabeculoplasty, which uses small pulses to minimize the amount of energy delivered to tissues. Another alternative is cyclophotocoagulation, which involves the use of lasers to reduce the ciliary body’s ability to produce fluid. If the ciliary body produces less fluid, intraocular pressure does not build as quickly.
Risks and Benefits of Using Laser Surgery
Before agreeing to any surgical procedure, patients should have a clear idea of the potential risks and benefits. In the case of using laser surgery to treat glaucoma, the immediate risks are low. Most patients only experience a very low amount of pain or discomfort during these surgeries, especially because a local anesthetic can be used to numb the eye before the procedure begins. This anesthetic should relieve any immediate pain. After surgery, patients may experience some irritation and their vision can become temporarily blurred. However, patients generally are able to resume their normal activities the next day.
Laser surgery may need to be repeated to sufficiently reduce the patient’s intraocular pressure. The success of the procedure depends on the patient’s age, the type of glaucoma and several other factors. Therefore, patients should have a thorough conversation with their ophthalmologist to understand the potential outcome. Usually, patients continue to take medications to control intraocular pressure after laser surgery, although the dose may be reduced. Some patients may experience a short-term increase in intraocular pressure. In rare instances, the increase in intraocular pressure does not subside and patients require traditional surgery. In addition, cyclophotocoagulation carries the risk of reducing intraocular pressure too much to support normal eye shape.
The other risk patients should understand is the small chance of developing cataracts following some types of laser surgery. Usually, the potential benefits of the procedure outweigh this risk, but it should be discussed. Cataracts result from abnormal protein structures in the eye’s lens and can be cured surgically.
When Laser Surgeries Do Not Work
Sometimes, laser surgery does not significantly reduce intraocular pressure. Other times, the benefits are only temporary. When this happens, patients may need more invasive procedures, such as a trabeculectomy, which is the removal of the trabecular meshwork, or the implantation of a shunt or other drainage device. The risks associated with these procedures are higher than with laser surgery, which is why laser surgery is usually tried first. In addition, non-surgical, minimally invasive treatment options may be possible. However, these techniques usually do not reduce pressure enough to make them the best option for patients who have already undergone laser surgery.
