LASER TREATMENT

Selective Laser Trabeculoplasty (SLT)

Selective Laser Trabeculoplasty (SLT) reduces eye pressure in people with Open-Angle Glaucoma. In certain cases, SLT can reduce eye pressure enough such that further eye drops are not needed. In other cases, SLT is used in conjunction with eye drops.

A lens is placed over the eye to direct the light to the trabecular mesh work.

How it Works

SLT uses an advanced laser system to target only specific cells of the eye-those containing melanin, a natural pigment. This allows for only these cells to be affected, leaving surrounding tissue intact. SLT improves the flow of fluid in the eye, which in turn lowers your SLT eye pressure.

SLT replaces an older procedure known as Argon Laser Trabeculoplasty (ALT). The main advantages of SLT over ALT include:
- A significant reduction in the formation of scar tissue in the drainage passage.
- The ability to repeat the laser for longer-lasting results.

SLT is for those patients:

• who have been diagnosed with glaucoma, glaucoma suspect, and/or ocular hypertension.
• whose doctor has determined that SLT is appropriate for controlling their intra-ocular pressure.
• who have advanced optic nerve damage and/or significant peripheral vision loss.
• who can no longer tolerate their medications due to side effects.
• who will not or cannot be absolutely faithful in taking their medications, whether due to medication costs, forgetfulness, physical disabilities, or mental disabilities.
• whose pressures are not controlled at or below target on maximal tolerated medication.
• whose pressures remain uncontrolled after ALT.

SLT - How Well It Works

SLT lowers the pressure in the eye about 85% of the time. However, many people will continue to need medication after laser treatment to keep the eye pressure low enough to prevent further damage to the optic nerve. The results of the SLT tend to decrease over time, but this procedure can be repeated, often with excellent results. In certain people with advanced glaucoma for whom SLT does not sufficiently reduce eye pressure, glaucoma surgery may be necessary.

SLT - What To Expect During and After Surgery

SLT is usually done as an outpatient procedure under topical anesthesia. Eye drops are put in the person's eye before the procedure to prevent a transient rise in eye pressure. Some people feel a sensation of heat in the eye during the SLT. However, there is usually no pain. The entire procedure usually takes place in less than 10 minutes. Typical follow-up with the doctor occurs approximately 2 weeks after the procedure.

SLT - Risks

Complications of SLT are rare. The most common complication of SLT is a transient increase in the eye pressure of the treated eye. An eye pressure test may be performed within the hour after the procedure in order to monitor for this.

Other complications of laser treatment may include, but are not limited to, a brief period of inflammation of the iris, the colored part of the eye, pain (rare) and transient blurred vision (rare).

While SLT laser treatment is used for patients with Open-Angle Glaucoma, laser iridotomy treatment is used for patients with Closed-Angle Glaucoma.

Laser Iridotomy

Closed-Angle Glaucoma is much less common than Open-Angle Glaucoma. In this condition the drainage passage of the eye becomes blocked resulting in an accumulation of fluid (aqueous humor) inside the eye. The pressure can rise suddenly causing damage to the optic nerve and peripheral vision. The purpose of an iridotomy is to preserve vision, not to improve it.

Laser Iridotomy is used to:

• Treat sudden closed-angle glaucoma;
• Treat the unaffected eye in people who have had an attack of sudden closed-angle glaucoma in one eye; and
• Prevent closed-angle glaucoma in people who have narrow drainage angles.

How Laser Iridotomy Works

Laser iridotomy uses a very focused beam of light to create a tiny drainage hole in the iris, the colored part of the eye (see image below). This opening allows aqueous humor, the fluid inside the eye, to flow between the anterior chamber, the front part of the eye, and the area behind the iris, the posterior chamber. This opening may decrease pressure in the eye and helps to prevent sudden closed-angle glaucoma.

Laser Iridotomy - How Well It Works

In people with an attack of sudden closed-angle glaucoma, laser iridotomy is usually successful but if scar tissue has developed in the drainage angle, high eye pressure may persist. In this situation, additional treatment, such as eye drops or surgery may be necessary to lower the pressure.

In people who have had an attack of sudden closed-angle glaucoma in one eye, laser iridotomy in the other eye will prevent a similar attack in that eye. Without treatment, there is a 50% chance that sudden closed-angle glaucoma will also develop in the unaffected eye.

Laser iridotomy is extremely successful in preventing sudden closed angle glaucoma in people who are at risk as a result of narrow drainage angles. Over time, the new drainage hole can become blocked. If this occurs, a repeat iridotomy is needed and is usually successful.

Laser Iridotomy - What to Expect During and After Procedure

Laser iridotomy is usually done as an outpatient procedure under topical anesthesia. Some people feel a sensation of heat in the eye during the procedure. The entire procedure usually takes place in less than 10 minutes. Depending on the patient's eye color, two different types of lasers may be needed to perform the procedure. There is usually no pain after laser iridotomy. Typical follow-up with the doctor occurs approximately 1 week after the procedure.

Laser Iridotomy - Risks

Complications of laser iridotomy may include, but are not limited to, brief blurred vision (common), transient increased in eye pressure and bleeding (rare). In a small percentage of patients the new drainage hole may close but can easily be reopened.