Glaucoma is a group of eye diseases that affect the optic nerve at the back of the eye. Without treatment, it can cause vision loss and blindness. Laser surgery can help to treat certain types of glaucoma.

This article provides an overview of the different types of laser eye surgery used to treat the different types of glaucoma.

We also discuss the success rate of laser surgery for glaucoma, and outline some of the risks and potential side effects. Plus, we answer some frequently asked questions about laser surgery for glaucoma.

The type of laser treatment your doctor or ophthalmologist recommends will depend on the type and severity of glaucoma you have.

The most common laser surgery treatments for glaucoma are selective laser trabeculoplasty (SLT), and laser peripheral iridotomy (LPI).

Selective laser trabeculoplasty (SLT)

Laser trabeculoplasty is so-called because it involves applying a laser beam to the trabecular meshwork of the eye. This is the spongy tissue between the iris and cornea that filters and drains the aqueous humor.

Selective laser trabeculoplasty (SLT) uses low energy laser pulses to treat specific cells inside the trabecular meshwork while leaving the functional parts intact. This results in minimal pain and scarring and means that you can safely undergo multiple SLT procedures, if necessary.

Doctors use SLT to treat open-angle glaucoma (OAC).

Laser peripheral iridotomy (LPI)

Laser peripheral iridotomy (LPI) is a treatment option for angle-closure glaucoma (ACG).

It involves using a higher energy laser to make a tiny hole in the edge of the iris. This hole exposes the trabecular meshwork, allowing fluid to drain from the eye.

The success rate of laser surgery for glaucoma depends on the type of laser surgery.

SLT success rate

A 2021 review and meta-analysis notes that SLT is successful in about 80% of cases, and can lower the interocular pressure (IOP) by as much as 20% to 30% after one or two procedures.

The same meta-analysis found that a repeat SLT procedure could effectively reduce IOP for up to 24 months. However, it was not able to verify the effectiveness of third, fourth, and fifth follow-up SLT procedures.

LPI success rate

Around 25% of LPI procedures do not effectively open the drainage angle. In such cases, individuals may require follow-up treatment, such as additional laser procedures or surgery.

A 2018 meta-analysis of 36 studies investigated the effectiveness of LPI among individuals with primary angle closure (PAC), which is a condition that can lead to glaucoma. PAC that develops into glaucoma is called PAC glaucoma (PACG).

Following LPI, the percentage of people requiring follow-up treatment was as follows:

  • 0% to 8% of eyes with suspected PAC needed follow-up
  • 42% to 67% of eyes with confirmed PAC needed follow-up
  • 21% to 47% of eyes with acute PAC (APAC) needed follow-up
  • 83% to 100% of eyes with PACG needed follow-up

Below are some of the risks and potential side effects of the two main types of laser surgery for glaucoma.

LPI risks and side effects

A 2018 meta-analysis noted the following complications among participants who had received LPI to help treat glaucoma and its symptoms.

  • IOP spikes: A temporary increase in IOP, occurring in 6% to 10% of cases.
  • Dysphotopsia: Unwanted visual phenomena like light bursts, streaks, or halos, occurred in 2% to 11% of cases.
  • Anterior chamber bleeding: Bleeding into the anterior chamber, which is the space between the iris and cornea, occurred in 30% to 41% of cases.
  • Cataract progression: The development of clouded areas on the lens of the eye (cataracts) occurred in 23% to 39% of cases.

SLT risks and side effects

According to a 2022 review, SLT is generally a safe procedure, with the main adverse effects being IOP spikes and mild inflammation. Medications can help to reduce the risk of both.

Make sure to follow your optometrist’s recommendations for recovery

The best way to avoid side effects and recover from laser surgery quickly is to follow the recovery directions that your surgical team will give you. This may include avoiding touching your eyes, bright lights, and operating heavy machinery like driving for several days.

You can learn more about laser eye surgery in this article.

Below are some answers to frequently asked questions about laser surgery for glaucoma.

Can laser surgery prevent glaucoma?

The results of a 2019 study suggest that LPI may help to prevent an attack of acute angle closure glaucoma which can rapidly lead to blindness.

How long does laser treatment last for glaucoma

The effects of SLT typically last between 1 to 5 years. Doctors may recommend repeating the procedure once the effects have worn off.

The long-term outcomes of LPI may differ on a case-by-case basis.

In a 2018 study, a large number of participants who received LPI for PAC required follow-up eye surgery within 3 years. Factors that increase the likelihood of additional treatment following LPI include:

  • older age
  • increased IOP prior to LPI treatment
  • cataract formation following LPI treatment

How many times can you have laser surgery for glaucoma?

It’s possible to receive multiple SLT treatments for glaucoma. However, scientists have yet to determine the effectiveness of more than two SLT treatments.

It’s also possible to receive more than one LPI treatment if the first one has closed.

The exact number of treatments your doctor recommends may differ depending on your individual needs. However, this laser treatment may cause more scarring compared to SLT, limiting the number of repeat LPI treatments you can safely receive.

What is the recovery like for laser surgery for glaucoma?

If you have SLT, your eye should recover quickly. In most cases, you should be able to return to your normal activities the following day.

Following LPI, you may experience some eye redness and discomfort accompanied by increased light sensitivity and blurred vision. These symptoms may last several days, during which time your doctor may prescribe medications to help manage the symptoms.

Because your eyes will still be adjusting and you may not be seeing as well as you normally would, it’s usually recommended to avoid driving for a few days after laser eye surgery.

The type of laser surgery your doctor recommends will depend on the type of glaucoma you have and its severity. There are two main types of laser eye surgery used to treat different types of glaucoma:

  • selective laser trabeculoplasty (SLT)
  • laser peripheral iridotomy (LPI)

Both SLT and LPI can be effective treatments for glaucoma, and both involve minimal downtime. However, both treatments can cause complications, such as spikes in eye pressure, and anterior chamber bleeding, although these are usually temporary and controllable with medication.

You can talk with your doctor or ophthalmologist about the potential benefits and risks of laser eye surgery for your type of glaucoma.