Trabeculoplastia láser selectiva: 10 preguntas frecuentes

La trabeculoplastia láser selectiva, o SLT (Selective Laser Trabeculoplasty), es una forma de cirugía con láser que se utiliza para disminuir la presión intraocular en el glaucoma.

Selective laser trabeculoplasty, or  SLT  , is a form of laser surgery used to lower intraocular pressure in glaucoma. It is used when eye drops do not lower eye pressure enough or cause significant side effects. It can also be used as an initial treatment in glaucoma. SLT  has been used for more than 25 years in  the United States and around the world.

  1. Who are candidates for the  SLT ?   Patients who have primary or secondary open-angle glaucoma (the drainage system in the front of the eye is open) and need to lower their intraocular pressure (IOP) are eligible for the procedure. Your ophthalmologist will make the final decision if you are a candidate.
  2. How does it work?  Laser energy is applied to the drainage tissue in the eye. This initiates a chemical and biological change in the tissue that results in better drainage of fluid through the drain and out of the eye. This ultimately causes a decrease in  IOP.  It may take 1 to 3 months for results to appear.
  3. Why is it called selective?   The type of laser used has minimal thermal energy absorption as it is only absorbed by the selected pigmented tissue in the eye. It is sometimes known as a “cold laser.” Because of this, the procedure produces less scar tissue and has minimal pain.
  4. What are the risks?  A key aspect of  SLT  is a favorable side effect profile, even when compared to glaucoma medications. Postoperative inflammation is common, but usually mild, and is treated with observation or eye drops or an oral nonsteroidal anti-inflammatory drug. There is approximately a 5% incidence of  IOP  elevation after laser, which can be controlled with glaucoma medications and usually disappears after 24 hours.
  5. How effective is it and how long does it last?   SLT lowers  IOP  by approximately 30% when used as initial therapy This is comparable to IOP  lowering  with the most potent and commonly used class of glaucoma medications (prostaglandin analogues). This effect may be reduced if the patient is already taking glaucoma medications. The effect will generally last between 1 and 5 years and in some cases longer than that. If it doesn’t last at least 6 to 12 months, it is generally not considered successful.
  6. What happens if it disappears?  If  SLT  is effective in lowering  IOP,  but this effect disappears over several years, the procedure can be repeated. Repeat treatments may or may not lower  IOP  as much as the first, and continued repetition of laser treatment will ultimately not be effective. Some doctors may choose to treat half of the tissue in the first treatment, then treat the second half at a later date (this is not considered repeat treatment, but is the completion of the treatment). If  SLT  is not initially successful, repeat treatment is unlikely to be effective. Alternatively, glaucoma medications can be used if the effect wears off over time.
  7. What happens if it doesn’t work? 
 If  SLT  does not lower  IOP,  then glaucoma is treated by other means, such as medications or surgery. The laser does not affect the success of these other types of treatment.
  8. What is the cost?   Since the procedure is an accepted treatment for glaucoma, and approved by the FDA,  it is covered by Medicare and health insurance. The cost for a person without insurance or with an insurance copay will vary.
  9. Will I still need to use glaucoma medications?  Some patients can be controlled with laser treatment alone. Others require additional lowering of  IOP  and therefore may also need glaucoma medications. Think of  SLT  as equivalent to a glaucoma medication. Just as some patients will require more than one glaucoma medication to control their  IOP,  some may also require laser and one or more glaucoma medications. It is important to remember that  SLT  is not a cure for glaucoma, nor are medications and surgery. Whatever method is used to treat glaucoma, proper follow-up and examinations with your eye care professional are essential.
  10. What are alternative laser treatments?  Other similar procedures include argon laser trabeculoplasty (  ALT ) and micropulse laser trabeculoplasty (  MLT ). ALT  was the  first laser trabeculoplasty procedure. It uses a thermal laser (heat) and may cause more scarring in the drainage angle than  SLT,  which may also limit its ability to be repeated. MLT  was designed to reduce the amount of energy delivered to the ocular tissues by pulsing the energy in small increments Therefore, it has similar potential benefits to  SLT  in terms of reduced inflammation, tissue healing, and ability to recur. The IOP  lowering results  of  SLT,  ALT  and  MLT  are similar.


In short,  SLT  is a laser treatment for open-angle glaucoma that lowers eye pressure. It can be used as an initial treatment, instead of eye drops, or as an additional treatment when medications do not lower eye pressure enough. It is usually effective, but the effect may wear off after a period of time. It can be repeated, but the effect may be reduced with repeated treatment. SLT  is not cure for glaucoma, but one of many tools to keep it under control.

Brian A. Francis, MD, MS

Brian A. Francis, MD, MS

Brian A. Francis, MD, MS is the Steiger Endowed Professor of Ophthalmology at the Doheny and Stein Eye Institutes, David Geffen School of Medicine, University of California, Los Angeles.