Should I Have Laser Treatment for My Glaucoma?
Quick Answer
You may need glaucoma laser if your drainage angle is narrow or drops alone fail to control your pressure.
LPI treats narrow angles, and SLT treats open angles, so your drainage angle decides which one you need.
Dr Shibal Bhartiya is a fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator with over 25 years of experience. Her approach focuses on identifying risk before damage is irreversible, simplifying treatment decisions, and protecting vision long-term. Emphasis on early detection, risk assessment, and continuity of care.
Does Laser Mean My Glaucoma Is Getting Worse?
Hearing the word “laser” can feel like a step up from drops. It is not. For the right eye, laser is often the gentlest option you have.
Glaucoma laser takes place in the clinic. You sit at the same machine used for your eye exam. There are no cuts and no stitches, and you go home the same day.
Why Do Doctors Use Laser for Glaucoma?
Glaucoma damages the optic nerve. Lowering the pressure inside the eye slows that damage.
Laser lowers pressure in one of two ways. It opens a blocked pathway, or it helps the eye’s own drain work better. Which way is right depends on the type of glaucoma you have.
What Is Laser Peripheral Iridotomy (LPI)?
What does LPI do?
Laser peripheral iridotomy makes a tiny hole in the edge of the iris. Fluid then flows through the hole instead of pushing against a narrow angle.
This stops the sudden pressure spikes of an angle-closure attack.
Who needs LPI?
Your doctor may advise LPI for:
- Angle-closure glaucoma
- Primary angle closure, where the angle touches the iris but the nerve is still healthy
- A very narrow angle with warning signs of an attack
- A fellow eye after an acute attack in the other eye
Not every narrow angle needs a laser. Many never close. Read whether you really need laser iridotomy.
What happens during LPI?
The visit takes about 5 to 10 minutes per eye.
- You receive numbing drops.
- Your doctor places a small lens on the eye.
- The laser makes the opening.
Most people feel a brief pinch or pressure. Many have a pressure-lowering drop afterwards.
What are the risks of LPI?
Most people have no lasting problems. Some notice glare, a faint arc of light or ghost images near the edge of vision. Bleeding at the opening and a short rise in pressure can also happen.
The opening rarely closes over. That is one reason you still need regular angle checks after LPI.
What Is Selective Laser Trabeculoplasty (SLT)?
What does SLT do?
SLT uses a low-energy laser on the eye’s drainage filter, called the trabecular meshwork. The laser does not burn or remove tissue. It prompts the eye to clear the filter and drain fluid better.
Who is SLT for?
SLT treats open-angle glaucoma and ocular hypertension. Your doctor may suggest it:
- As your first treatment
- When drops do not control your pressure
- When drops cause side effects
- When daily drops are hard to use
SLT is not the right laser for a closed or very narrow angle. Your doctor must check the angle first.
What does the evidence say about SLT?
The LiGHT trial compared SLT first with drops first in newly diagnosed open-angle glaucoma. After three years, about three in four eyes in the laser group needed no drops. Laser first also kept pressure well controlled.
What happens during SLT?
The visit takes 10 to 15 minutes per eye.
- You receive numbing drops.
- Your doctor places a lens that focuses the laser on the drain.
- The laser delivers a series of gentle pulses.
You may see flashes and hear soft clicks. Your vision may stay blurred for a few hours. Your doctor checks your pressure the same day.
How long does SLT take to work, and how long does it last?
The full effect takes four to six weeks. Keep using your drops until your doctor says to stop.
In some eyes the effect fades over several years. Doctors can often repeat SLT.
How Do LPI and SLT Compare?
| Feature | LPI | SLT |
|---|---|---|
| Treats | Narrow or closed angles | Open angles |
| Target | Iris | Drainage filter |
| How it works | Makes a small opening | Helps the filter drain better |
| Time per eye | 5 to 10 minutes | 10 to 15 minutes |
| Time to work | Immediate flow change | Four to six weeks |
| Lasting effect | Usually permanent | May fade over years |
| Can it be repeated? | Rarely needed | Often yes |
| Common aftereffect | Glare or ghost images | Mild blur, brief pressure rise |
What Do Doctors Often Miss About Glaucoma Laser?
The angle decides the laser. Your doctor needs a direct look at your drainage angle, called gonioscopy, before choosing. The wrong laser for the wrong angle wastes time.
Laser lowers pressure. It does not cure glaucoma. You still need a target pressure and regular checks. OCT scans and visual field tests tell you whether the nerve is stable.
A good pressure reading on day one is not the end. Pressure moves through the day and across the years. A laser that worked well can wear off quietly.
LPI does not always fix the whole problem. Some eyes with narrow angles still need drops, further laser or cataract surgery after LPI.
When Should I See a Doctor After Glaucoma Laser?
See a Doctor Urgently
Seek same-day care if you have:
- Severe eye pain
- Sudden drop in vision
- Severe headache with nausea or vomiting
- Halos around lights with a red, hard-feeling eye
See a Doctor
Book a visit if you notice:
- Blur that lasts longer than a day
- Redness or light sensitivity that does not settle in a few days
- Glare that bothers you in daily life
- You have missed your follow-up appointment
What Does This Mean for You?
Laser is a treatment option, not a sign of failure. It works best when your doctor matches the laser to your drainage angle.
Ask which type of glaucoma you have, what your target pressure is, and what happens if the laser does not work. A clear answer to all three is a good sign.
Frequently Asked Questions
Is glaucoma laser treatment painful?
Most people feel little or no pain. Numbing drops are used first. You may feel a brief pinch or pressure, and sometimes a dull ache afterwards.
Can SLT replace my glaucoma eye drops?
In some people with open-angle glaucoma, yes. SLT can reduce the number of drops or delay the need for them. Others still need drops after the laser, so keep using them until your doctor advises otherwise.
Is LPI a permanent treatment?
The opening it makes usually lasts. You still need regular checks of your angle, pressure and optic nerve. LPI prevents angle closure, but it does not treat other causes of high pressure.
How well does SLT work?
Most eyes respond. In the LiGHT trial, about three in four eyes treated with laser first needed no drops at three years. Response varies from person to person.
Do I need laser if my drops are working?
Not always. Many people do well on drops with regular monitoring. Laser makes sense when your pressure stays high, when drops cause problems, or when your angle is at risk of closing.
Has someone advised laser for your glaucoma?
Upload your reports for a structured second opinion with Dr Bhartiya before you decide.
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This page is a part of the Glaucoma Hub. you may want to read about Glaucoma Progression, , and Risk Stratification in Glaucoma. Other articles of interest could be Advanced Glaucoma Care in Gurgaon, What Good Glaucoma Care Actually Optimises For, What Happens If Glaucoma Is Left Untreated?, More Glaucoma Eye Drops is Not Better Glaucoma Care, 5 Mistakes Patients Make in Glaucoma Care, Glaucoma Tests Explained, and Do You Really Need Treatment for Glaucoma?
Here’s another heartening patient story: a patient who avoided eye drops with laser.
About the Author
This article was written by Dr Shibal Bhartiya, fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator, Clinical Director at Marengo Asia Hospitals, Gurugram, known for ethical, patient-centred glaucoma care and independent glaucoma second opinions. She is also the Program Director for Community Outreach & Wellness; and for the Marengo Asia International Institute of Neuro and Spine.
Dr Bhartiya has published peer-reviewed research on glaucoma management, examining how treatment decisions should balance medical evidence, patient preferences, and long-term vision outcomes. She is also a committed patient advocate and mainstream medical columnist, translating complex ophthalmic evidence into actionable public health insights across leading national platforms including NDTV and OnlyMyHealth
As Editor-in-Chief of Clinical and Experimental Vision and Eye Research and Executive Editor of the Journal of Current Glaucoma Practice (Pubmed Indexed, official journal of the International Society of Glaucoma Surgery). Her 200+ publications, including 90+ PubMed-indexed publications and 28 edited textbooks span glaucoma biology, surgical outcomes, health equity, and emerging diagnostics.
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Last Reviewed: October 2026