What Is Laser Trabeculoplasty for Glaucoma?

If drops alone aren't keeping your eye pressure where your doctor wants it, laser trabeculoplasty is one of the next options they may raise. There's no incision and no scalpel involved. Instead, a focused laser is aimed at the eye's own drainage tissue to help fluid leave the eye more easily — and the whole treatment is done while you sit at a machine that looks much like the one used for a routine eye examination.

The video at the top of this page shows the view from inside the front of the eye during a YAG laser trabeculoplasty, in just under four minutes of footage. Its description is specific about what you're seeing: a LASAG YAG laser in thermal mode treating the trabecular meshwork — the drainage tissue that sits between the cornea and the iris.

Step one: understand the drain being treated

Inside your eye, a clear fluid called aqueous humour is constantly being made and constantly draining away. It leaves through a spongy ring of tissue at the front of the eye, the trabecular meshwork. When that drain works well, pressure inside the eye stays balanced. When it becomes sluggish — as happens in the common open-angle form of glaucoma — pressure can build, and over time that raised pressure can damage the optic nerve at the back of the eye.

That's the background explained in our overview of glaucoma and how it is treated. Trabeculoplasty doesn't create a new drain, and it doesn't remove anything. It treats the existing meshwork, using laser energy to encourage fluid to pass through it more freely so pressure can fall.

Step two: settling in at the laser

You sit at a slit-lamp laser unit, chin on the rest and forehead against the bar — the same posture as an eye examination, which is exactly what the featured setting looks like in practice. Numbing drops are placed on the eye, and a special contact lens is set gently on its surface. That lens does two jobs: it holds the eye steady and it carries mirrors that let the doctor see the drainage angle clearly, the narrow space where the meshwork sits.

You stay awake for this. There's no general anaesthetic and no operating theatre in the usual sense — it's a clinic-room laser treatment.

Step three: the laser pulses themselves

Once the angle is in view, the doctor directs brief laser pulses onto the meshwork, working around its circumference a section at a time. In the anchor video you see this from the inside: the view is of the front chamber of the eye itself as the treatment is applied to the tissue between cornea and iris.

There are two names you may hear for this family of treatment. The anchor video uses a YAG laser in thermal mode. A related approach, selective laser trabeculoplasty (SLT), is the subject of a second recording on this site, "Laser Surgery for Glaucoma", whose description calls SLT a virtually painless, minimally invasive procedure. Your specialist will explain which approach, if any, fits your eye — the choice depends on your type of glaucoma and what treatment you've already had.

You may see flashes of light as the pulses are delivered, and most people describe pressure or awareness of the lens rather than sharp pain, helped by the numbing drops.

Step four: straight after, and the weeks that follow

When the lens comes off, that's usually the treatment finished. Eye pressure is typically checked again after a short wait, because pressure can occasionally rise briefly straight after laser treatment, and your team will want to see it settled before you leave. Drops may be given for a short period afterwards, and you'll be told whether to keep using your existing glaucoma drops — don't stop them on your own unless your doctor says so.

Here's the part that catches people out: the effect isn't instant. Pressure lowering, when it happens, tends to develop gradually over the following weeks, which is why a follow-up pressure check is part of the plan rather than an afterthought. Laser trabeculoplasty also doesn't restore vision that glaucoma has already taken, and it doesn't cure glaucoma — it's one way of lowering pressure to help protect the vision you still have. If laser treatment isn't enough on its own, other options remain, including the filtration operation described in our guide to trabeculectomy. And because cataract and glaucoma often travel together in the same eye, our cataract guide is useful background if both are being discussed for you.

References & further reading

• MedlinePlus — Glaucoma: https://medlineplus.gov/glaucoma.html
• National Eye Institute — Glaucoma: https://nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/glaucoma
• American Academy of Ophthalmology — What Is Glaucoma?: https://www.aao.org/eye-health/diseases/what-is-glaucoma

Frequently Asked Questions

Does laser trabeculoplasty involve any cutting?

No. No incision is made. A special lens sits on the surface of the numbed eye and brief laser pulses are directed through it onto the trabecular meshwork, the eye's drainage tissue, while you sit at a slit-lamp unit.

Will I feel the laser?

Numbing drops are used and most people describe seeing flashes of light and feeling the lens on the eye rather than sharp pain. A related form of the treatment, selective laser trabeculoplasty, is described on this site as virtually painless. Tell the team treating you if you're uncomfortable — they can pause.

How soon will my eye pressure come down?

Not immediately, in most cases. Any lowering tends to develop gradually over the weeks after treatment, and pressure is checked again on the day and at follow-up so your team can judge the effect. Keep using any prescribed drops unless your doctor tells you to change them.

Can laser trabeculoplasty cure glaucoma or bring back lost vision?

No. It aims to lower eye pressure by helping fluid drain through the eye's own meshwork. Lowering pressure helps protect remaining vision, but it cannot restore sight already lost to glaucoma and it is not a cure — ongoing monitoring is still needed.

MedicalVideos.com has published trusted medical videos since 2007. The site was founded by Dr. Mohamed Ibrahim, MD, PhD — physician-scientist.

Educational only — this article is general information about laser trabeculoplasty, not medical advice and not a diagnosis. Whether laser treatment is suitable for your glaucoma, and which type, belongs to your own eye specialist after a full examination of your eyes.