the eye institute of west florida

Selective Laser Trabeculoplasty (SLT)

Selective Laser Trabeculoplasty (SLT)

Selective Laser Trabeculoplasty, or SLT, is a form of laser surgery that is used to lower intraocular pressure in glaucoma.

Who is a candidate for SLT?

Patients who have open-angle glaucoma (the drainage system in the front part of the eye is open) and need to lower their intraocular pressure (IOP) are eligible for the procedure. Your eye doctor will determine if you are a candidate.

How does it work?

Laser energy is applied to the drainage tissue in the eye. This starts a chemical and biological change in the tissue, resulting in better drainage of fluid through the drain and out of the eye. This eventually results in lowering of IOP. It may take 1-3 months for the results to appear.

Why is it called Selective?

The type of laser used has minimal heat energy absorption because it is only taken up by selective pigmented tissue in the eye. Sometimes it is referred to as a “cold laser.” Because of this, the procedure produces less scar tissue and has minimal pain.

What are the risks?

One key aspect of SLT is a favorable side effect profile, even when compared with glaucoma medications. Post-operative inflammation is common but generally mild, and treated with observation, eye drops or an oral non-steroidal anti-inflammatory drug. There is approximately a 5% incidence of IOP elevation after laser, which can be managed by glaucoma medications and usually goes away after 24 hours.

How effective is it?

SLT lowers the IOP by about 30% when used as initial therapy. This is comparable to the IOP lowering of the most powerful and commonly used class of glaucoma medication (prostaglandin analogs). This effect may be reduced if the patient is already on glaucoma medications.

How long does the effect last?

The effect will generally last between 1-5 years, and in rare cases, longer than that. If it does not last at least 6-12 months, it is usually not considered successful.

What happens if it wears off?

If SLT is effective at lowering IOP, once it wears off over several years, the procedure can be repeated. The second treatment may not be as effective as the first and may not last as long. If SLT is not initially successful, repeat treatment is not likely to be effective. Alternatively, glaucoma medication can be used if the effects wears off over time. 8. What happens if it doesn’t work? If SLT fails to lower the IOP, then the glaucoma is treated by other means such as medications or conventional surgery. The laser does not affect the success of these other types of treatment.

Will I still need to use glaucoma medications?

Some patients can be controlled with just laser treatment. Others require additional IOP lowering and may therefore need to use glaucoma medication as well. Think of the SLT as equivalent to one glaucoma medication. Just as some patients will require more than one glaucoma medication to control their IOP, some may also require laser plus one or more glaucoma medications. It is important to remember that SLT is not a cure for glaucoma, just as medication and surgery are not. Whatever method is used to treat glaucoma, appropriate follow up and testing with your eye care professional is critical.

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Meet Your Glaucoma Care Specialists

Jeffrey S. Schwartz, MDJeffrey S. Schwartz, MD is the first full-time board-certified, fellowship-trained glaucoma specialist in Pinellas County. He has been with The Eye Institute since 1988. His practice is limited to diagnosis, treatment, laser therapy and surgery of patients with glaucoma and other related diseases. Dr. Schwartz completed his residency at The University of South Florida and his glaucoma fellowship at the prestigious Jules Stein Eye Institute at UCLA. He is active in medical research and has made major contributions to the treatment and management of glaucoma. Dr. Schwartz is certified by the American Board of Ophthalmology, He serves as the medical consultant to pharmaceutical companies in the search for more effective glaucoma medications. Dr. Schwartz is on the Board of Directors and is the Medical Consultant for the Lighthouse of Pinellas and has served as the Medical Director for a number of health care plans.


Sandra M. Johnson, MDSandra M Johnson, MD is a fellowship-trained specialist who has been on the faculty of several of the most renowned educational institutions in the United States; Dartmouth, University of North Carolina, and the University of Virginia. She joined The Eye Institute of West Florida after 20 years of experience in all aspects of glaucoma. She follows patients as their primary glaucoma caregiver as well as seeing patients as a consultant to other eye care professionals. She is skilled in the medical, laser and surgical management of the disease. While working as a clinician-educator, she wrote scientific papers and chapters and contributed to many eye meetings. Since 2006, she has cultivated an interest in international ophthalmology and served ORBIS, as a volunteer eye faculty in many foreign countries.


Siddarth Rathi, MDSiddarth Rathi, MD, MBA,is a nationally recognized glaucoma specialist and physician innovator. He is the former Director of Teleophthalmology and Assistant Professor of Ophthalmology at NYU Langone School of Medicine. Dr. Rathi completed his graduate medical studies at Boston University and M.B.A. at Harvard Business School. His residency was completed at the NYU Medical Center and Glaucoma Fellowship at the Bascom Palmer Eye Institute – a world-renowned Institution. While attending school, Dr. Rathi received various awards to his acclaim. He was awarded the American Glaucoma Society Mentoring for the Advancement of Physician-Scientists Grant Award. Over the course of his career, Dr. Rathi has published articles in peer-reviewed journals, secured grant funding, and presented at national and international conferences. Dr. Rathi’s interests include artificial intelligence in medicine, telemedicine, and big data analytics. He spends his free time with his family and enjoys traveling.

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