Selective Laser Trabeculoplasty (SLT)

Glaucoma is a common eye condition that can lead to vision loss if not properly managed. One of the treatments available is Selective Laser Trabeculoplasty (SLT), a laser procedure designed to lower eye pressure. Here, Dr. Rehman Siddiqui will answer frequently asked questions about SLT to help you understand how it works and its benefits over traditional treatments like eye drops.

What is Selective Laser Trabeculoplasty (SLT)?

Selective Laser Trabeculoplasty, or SLT, is a laser treatment used to reduce intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. By targeting specific cells in the eye’s drainage system, SLT helps improve fluid outflow, which lowers eye pressure and prevents damage to the optic nerve.

How does SLT work?

SLT uses short pulses of low-energy laser light to target the pigmented (melanin-containing) cells in the trabecular meshwork—the eye’s natural drainage system. The laser stimulates these cells without causing damage, prompting a biological response that enhances fluid drainage. This process reduces intraocular pressure, helping to control glaucoma progression.

How is SLT different from traditional glaucoma treatments like eye drops?

While eye drops are a common first-line treatment for glaucoma, they require daily use and strict adherence to be effective. SLT offers an alternative by providing a one-time (or occasionally repeated) procedure that doesn’t rely on patient compliance. Unlike eye drops, SLT doesn’t involve medication side effects or the inconvenience of daily application.

What are the advantages of SLT over eye drops?

1. Convenience: SLT eliminates the need for daily medication, making it easier for patients who struggle with eye drop routines.
2. Reduced Side Effects: Eye drops can cause local irritation or systemic side effects. SLT minimizes these risks.
3. Cost-Effective: Over time, SLT can be more economical by reducing or eliminating the need for expensive medications.
4. Improved Compliance: With SLT, there’s no worry about forgetting doses or incorrect application.
5. Non-Invasive and Safe: SLT is a gentle procedure that doesn’t involve cuts or incisions.

Does SLT cause any tissue damage to the eye?

No, SLT is designed to avoid tissue damage. The “selective” aspect means the laser specifically targets pigmented cells without affecting surrounding tissues. The energy used is low enough to stimulate healing without causing scarring or structural changes to the eye’s drainage system.

Can SLT be repeated over time if necessary?

Yes, SLT can be safely repeated. Since it doesn’t cause damage or scarring, the procedure can be performed multiple times if intraocular pressure rises again in the future. This makes SLT a flexible long-term treatment option for managing glaucoma.

What does the long-term LIGHT trial data say about SLT?

The LIGHT (Laser in Glaucoma and Ocular Hypertension) trial was a significant study that compared SLT to traditional eye drops over a period of three years. The findings revealed that:

1. Effectiveness: SLT was as effective as eye drops in lowering intraocular pressure.
2. Safety: Patients treated with SLT experienced fewer side effects.
3. Quality of Life: SLT patients reported a higher quality of life due to reduced medication burden.
4. Cost Savings: SLT proved to be more cost-effective in the long term.

These results support SLT as a first-line treatment for glaucoma, offering patients an effective and convenient alternative to eye drops.

Is SLT safe?

Yes, SLT is considered a safe procedure. It’s non-invasive and has a low risk of complications. Any side effects are typically mild and temporary, such as slight redness or discomfort that usually resolves within a day or two.

What can I expect during the SLT procedure?

• Preparation: You’ll receive numbing eye drops to ensure comfort.
• Procedure: A special contact lens is placed on your eye to help focus the laser. You’ll be asked to sit at a slit-lamp microscope (similar to a regular eye exam). The doctor will deliver laser pulses to the trabecular meshwork.
• Duration: The procedure typically takes about 5-8 minutes per eye.
• Comfort: You may see flashes of light, but most patients report minimal discomfort.

What happens after the SLT procedure?

• Immediate Aftercare: You might experience mild blurriness or redness, which usually subsides quickly.
• Medication: You may be prescribed  anti-inflammatory eye drops for a few days. It is important to continue with the anti-glaucoma medications, until you are advised to reduce or stop them.
• Follow-Up: Regular check-ups will monitor your eye pressure and assess the effectiveness of the treatment.
• Activity: You can typically resume normal activities immediately.

Who is a good candidate for SLT?

SLT is suitable for:

• Patients with Open-Angle Glaucoma or Ocular Hypertension: It’s effective in lowering eye pressure in these conditions.
• Those Struggling with Eye Drops: If you find it challenging to apply eye drops consistently or experience side effects.
• Patients Seeking a Medication-Free Option: SLT offers an alternative to daily medications.

Are there any risks or side effects associated with SLT?

While SLT is generally safe, some potential side effects include:

• Temporary Eye Redness or Irritation: Usually resolves within a few days.
• Inflammation: Mild inflammation that can be treated with eye drops.
• Transient Eye Pressure Increase: Rarely, eye pressure may spike temporarily after the procedure.

Serious complications are rare, and your doctor will monitor you to address any issues promptly.

How effective is SLT at lowering eye pressure?

SLT can reduce intraocular pressure by about 20-30%. The exact amount varies among individuals, but many patients achieve significant pressure reduction. The effectiveness can be comparable to that of eye drops, as supported by the LIGHT trial and other studies.

How long does the effect of SLT last?

The pressure-lowering effects of SLT can last from one to five years. Over time, the effect may diminish, but because SLT can be repeated safely, it remains a viable long-term treatment option.

How many times can SLT be repeated?

There’s no strict limit to how many times SLT can be repeated. Since it doesn’t cause scarring or damage, additional treatments can be performed if intraocular pressure rises again. Your doctor will decide the appropriate timing for repeat procedures based on your eye’s response.

Will I still need to use eye drops after SLT?

Some patients may still need eye drops after SLT, but many can reduce or eliminate their use. The goal is to manage your eye pressure effectively, whether through SLT alone or in combination with medications. Your doctor will tailor a treatment plan to your needs.

How does SLT avoid causing tissue damage?

SLT’s laser targets only the pigmented cells in the trabecular meshwork, leaving surrounding tissues unaffected. The laser energy is low and delivered in short pulses, which stimulates a healing response without causing burns or scars. This selective approach ensures the drainage system’s structure remains intact.

What did the LIGHT trial reveal about the long-term benefits of SLT?

The LIGHT trial demonstrated several long-term benefits of SLT:

• Sustained Eye Pressure Reduction: SLT maintained effective pressure control over three years.
• Reduced Need for Medications: Many patients required fewer or no eye drops after SLT.
• Improved Quality of Life: Patients reported higher satisfaction due to less dependence on medications.
• Economic Advantages: Overall treatment costs were lower for SLT patients compared to those on eye drops.

These findings highlight SLT’s effectiveness and practicality as a long-term glaucoma treatment.

Conclusion

Selective Laser Trabeculoplasty (SLT) is a safe, effective, and convenient option for managing glaucoma. It offers several advantages over traditional eye drops, including reduced side effects, improved compliance, and the ability to be repeated without causing tissue damage. The long-term LIGHT trial data supports SLT as a first-line treatment, demonstrating its effectiveness and benefits over time.

If you’re considering SLT or want to explore your glaucoma treatment options, talk to your eye doctor. They can provide personalized advice and help you make an informed decision about your eye health.

Additional Resources:

•Glaucoma Research Foundation: www.glaucoma.org

•American Academy of Ophthalmology: www.aao.org

Disclaimer: This post is for informational purposes only and should not replace professional medical advice. Always consult with a qualified healthcare provider regarding any medical condition or treatment.