Selective Laser Trabeculoplasty (SLT)

Selective Laser Trabeculoplasty

What is glaucoma?

Glaucoma is a degenerative disease that if left untreated can cause permanet damage to the optic nerve resulting in gradual vision loss and eventual blindness. Damage to the optic nerve, due to glaucoma, is usually caused by elevated intraocular pressure (I.O.P). Clear fluid, called aqueous humor circulates through the eye providing nourishment to the tissues pressure to help maintain the shape of the eye.

Open Angle Glaucoma (O.A.G.), occurs when there is an increase in fluid production or a decrease in fluid drainage, Over time, as the optic nerve fibers are destroyed, peripherial (side) vision is lost.

Selective laser trabeculoplasty(SLT)(1) uses a neodymium: YAG laser to focus light energy on the internal drainage channel of the eye. SLT tagets the pigmented (melanin-containing) cells in the trabecular meshwork using a very short application of light. Because SLT uses a low amount of energy, the surrounding tissue is not damaged. The treatment allows the drain to work more efficiently, successfully lowering eye pressure more than 80 percent of the time.

After SLT, your eye pressure may increase over time. By five years, up to half of the people treated with SLT experience a rise in eye pressure. Your doctor will need to continue to monitor your eye pressure and can repeat the SLT treatment if needed.

Who is a candidate for SLT?

Laser surgery can reduce the amount of medication you may need and is often recommended when you have trouble inserting eyedrops or are not using eyedrops on a regular basis. SLT can also be used in addition to taking medicines or as a first line of treatment.

How is SLT done?

The procedure is done at Dr. Piemontesi's office and usually takes less than 10 minutes. First, anesthetic drugs are used to numb the eye. Additional drops are given to control eye pressure. While you are seated at the examining microscope, the laser energy is then focused through a lens to treat the drainage channel. You will experience a flash of light with each laser application. There is rarely discomfort with this treatment

After treatment your eye pressure will be monitored. Dr. Piemontesi may want to monitor your eye pressure for one to two hours after the procedure. Very rarely, eye pressure can rise, requiring additional treatment. Anti-inflammatory medications are often prescribed for several days after the procedure.

The SLT laser beam stimulates the trabecular meshwork to exert a biological response which initiates the activation of cells that help open the drain over a period of months. This enhances the flow of aqueous fluid through the drainage angle lowering the eye pressure.

Your vision will be blurry immediately after the treatment but should clear within hours. Most people can return to their normal activities the day after laser surgery.

It will take several weeks for the laser treatment to take full effect. Your doctor will want to check your eye pressure one to two months after the procedure. If you eye pressure is not lower at the first visit, some additional effect can be gained up to three months after treatment, If lower eye pressure is needed, your eye M.D. will help you decide whether additional laser treatment, medication or surgery is required.

What are the risks of SLT?

As with any procedure, there are some risks of complications with SLT. Possible complications include:

  • failure to adequately lower the eye pressure
  • increased pressure in the eye, possibly requiring medications or surgery to lower it;
  • inflammation in the eye causing pain, redness, or blurred vision;

There are always risks associated with a procedure and medications. However, the risks should be balanced against the greater risk of leaving glaucoma untreated and losing your vision.

If you have any questions about SLT for open angle glaucoma, your should discuss them with your eye M.D.

Sources: American Academy of Ophthalmology - Patient Education