Laser Glaucoma Procedures

Introduction

If you have been diagnosed with glaucoma, or your ophthalmologist has raised the possibility of laser treatment, you are likely trying to understand what these procedures actually involve. Glaucoma is a group of eye conditions in which the optic nerve — the nerve that carries visual information from the eye to the brain — becomes progressively damaged, usually because of raised pressure inside the eye. Lowering that pressure is the single most important step in protecting the vision you still have.

Laser glaucoma procedures are a family of treatments that use focused light energy to lower eye pressure. They can be used early in the disease, when eye drops alone are not enough, when drops cause side effects, or to reduce the risk of a sudden, severe pressure rise. In some forms of glaucoma, laser is now offered as the first treatment rather than after drops.

This guide explains what laser glaucoma procedures are, the different types and when each is used, how to prepare, what happens during and after the procedure, what realistic outcomes look like, and how long-term care continues afterwards. Glaucoma is a lifelong condition, so laser treatment is one part of a longer plan to protect your sight.

What Are Laser Glaucoma Procedures?

The eye constantly produces a clear fluid called aqueous humour, which fills the front of the eye and then drains out through a fine mesh-like tissue called the trabecular meshwork, located in the drainage angle between the iris (the coloured part) and the cornea (the clear front surface). When this drainage is blocked, narrowed, or simply less efficient than the eye needs, fluid builds up. The result is raised intraocular pressure (IOP), which over time damages the optic nerve.

Laser glaucoma procedures use a precisely targeted beam of light to make small, controlled changes inside the eye that:

• Improve the way fluid drains out of the eye
• Open a blocked or narrow drainage angle
• Reduce how much fluid the eye produces

Lower fluid pressure means less mechanical stress on the optic nerve, which slows or prevents further vision loss.

Unlike traditional glaucoma surgery, laser procedures usually involve no incisions, no stitches, and no overnight hospital stay. Most are performed at a slit lamp (the microscope your ophthalmologist uses for eye examinations) in an outpatient clinic and take only a few minutes. You stay awake. The eye is numbed with drops.

Laser treatment is not a cure for glaucoma. Glaucoma damage is permanent, and the goal of any treatment — drops, laser, or surgery — is to preserve the vision you have today, not to restore vision already lost.

Types of Laser Glaucoma Procedures

There are several different laser procedures, each designed for a different type of glaucoma or stage of disease. The choice depends on whether your drainage angle is open or narrow, how high your pressure is, how advanced your nerve damage is, and how you have responded to other treatments.

Selective Laser Trabeculoplasty (SLT)

SLT is used for open-angle glaucoma, the most common form. In this type, the drainage angle is anatomically open but not draining fluid efficiently. SLT uses short, low-energy pulses of laser light directed at the trabecular meshwork. The energy stimulates the meshwork cells without causing thermal damage to surrounding tissue, improving fluid outflow over the following weeks.

SLT can be used as a first-line treatment instead of eye drops, as an add-on when drops are not lowering pressure enough, or when drop side effects or daily use are difficult to manage. Large clinical trials in recent years have supported SLT as a reasonable first treatment in many people with open-angle glaucoma or ocular hypertension (raised pressure without nerve damage yet). The American Academy of Ophthalmology and the European Glaucoma Society both describe SLT as a well-established option at multiple points in the treatment pathway.

A typical SLT session takes about 10 to 15 minutes per eye. The effect builds over four to six weeks. SLT can be repeated if its effect wears off after a few years, which is one of its advantages.

Argon Laser Trabeculoplasty (ALT)

ALT is the older laser treatment for the trabecular meshwork. It uses a continuous-wave argon laser that produces more heat and some scarring of the meshwork. ALT also lowers pressure in open-angle glaucoma but is repeated less easily than SLT because the meshwork tissue can only tolerate a limited number of treatments. In most centres today, SLT has largely replaced ALT, though ALT is still used in some settings.

Laser Peripheral Iridotomy (LPI)

LPI is used when the drainage angle is narrow or closed — either because of an acute angle-closure attack, chronic angle-closure glaucoma, or a narrow-angle anatomy that puts the eye at risk of future closure. In these eyes, the iris is too close to the cornea and blocks fluid from reaching the trabecular meshwork.

LPI is often a preventive procedure performed before an acute attack happens, particularly when imaging or examination shows the angle is at risk. In an acute angle-closure attack — with severe pain, redness, blurred vision, headache and nausea — LPI is part of urgent treatment after the pressure is first brought down with medications.

An LPI takes about 5 to 10 minutes per eye.

Laser Iridoplasty (Argon Laser Peripheral Iridoplasty)

Iridoplasty uses laser energy applied to the peripheral iris to shrink and pull it away from the drainage angle in eyes where the angle remains narrow despite an LPI, or where the iris configuration is unusual (such as plateau iris). It is used less commonly than LPI but has a defined role in selected angle-closure situations.

Cyclophotocoagulation

There are two main forms:

• Transscleral cyclophotocoagulation (TSCPC), in which the laser is applied through the white of the eye from outside. Traditional continuous-wave TSCPC was historically reserved for advanced or refractory glaucoma, often in eyes with limited vision potential, because of a higher risk of inflammation.
• MicroPulse transscleral laser therapy, a newer variant that delivers the laser in short bursts with rest periods, reducing heat damage to surrounding tissue. It is being used in a wider range of glaucoma stages, although long-term comparative data are still developing.
• Endoscopic cyclophotocoagulation (ECP), performed inside the eye through a small incision, usually at the time of cataract surgery.

Cyclophotocoagulation is often considered when drops, trabeculoplasty, and incisional surgery have not adequately controlled pressure, or when conventional surgery is not suitable.

Why Is Laser Treatment Performed?

Laser glaucoma procedures may be considered in several situations. Your ophthalmologist will weigh the type and stage of your glaucoma, your eye pressure trend, the appearance of your optic nerve, your visual field test results, and your overall health.

Common reasons laser is recommended include:

• Open-angle glaucoma or ocular hypertension, as an initial treatment or alongside or instead of eye drops
• Difficulty using eye drops — for example because of side effects, allergy, dexterity problems, or the burden of multiple daily drops
• Inadequate pressure control on medications
• Narrow or closed drainage angles, where LPI is used to reduce the risk of an acute angle-closure attack
• Acute angle-closure glaucoma, as part of urgent management once initial pressure-lowering medications take effect
• Advanced or treatment-resistant glaucoma, where cyclophotocoagulation may be used to reduce fluid production

Whether laser is appropriate, and which type, is a clinical decision your ophthalmologist makes after a detailed examination.

Who Is a Candidate?

Candidacy depends on the type of glaucoma and the anatomy of the eye. In general, you may be considered for laser treatment if:

• You have a confirmed diagnosis of glaucoma or ocular hypertension
• Your drainage angle anatomy is suitable for the specific laser planned
• Your cornea is clear enough to allow the laser to reach its target
• You are able to sit still at a slit lamp for several minutes

Laser may be less suitable, or require modification, when:

• The cornea is cloudy, scarred, or severely swollen, blocking the laser’s view
• The eye has very advanced damage and very high pressure, where incisional surgery is more likely to achieve the necessary pressure drop
• Certain types of secondary glaucoma respond poorly to specific laser treatments

Your ophthalmologist will explain the realistic chance that laser will reach your target pressure and what the next step would be if it does not.

Alternatives to Laser Treatment

Laser is one of several ways to lower eye pressure. Other options include:

Eye Drops

Pressure-lowering eye drops remain a mainstay of glaucoma treatment. Common classes include prostaglandin analogues (often used once daily), beta-blockers, alpha agonists, carbonic anhydrase inhibitors, and rho kinase inhibitors. Drops can be very effective but require daily use, sometimes more than once, and may cause local side effects such as redness, irritation, lash changes, or changes in iris pigmentation, as well as occasional systemic effects.

Oral Medications

Oral carbonic anhydrase inhibitors can lower pressure but are usually reserved for short-term use because of systemic side effects.

Incisional Glaucoma Surgery

When laser and drops do not control pressure adequately, surgical options include:

• Trabeculectomy, which creates a new drainage channel from inside the eye to a small pocket under the conjunctiva (the thin membrane covering the white of the eye)
• Glaucoma drainage devices (tube shunts), small implants that redirect fluid to a reservoir at the back of the eye
• Minimally invasive glaucoma surgery (MIGS), a growing group of procedures that use tiny stents or microsurgical techniques to improve drainage, often performed alongside cataract surgery

Observation

For very mild ocular hypertension with no nerve damage, careful monitoring without immediate treatment is sometimes appropriate. This is a clinical decision based on risk factors and the rate of any change.

Which path is right for any individual is a decision made with the ophthalmologist, based on disease stage, anatomy, life circumstances, and treatment history.

Preparing for Laser Treatment

Preparation is generally simple. Your ophthalmologist will tell you what to do before your appointment. Common steps include:

• Continuing your usual eye drops unless told otherwise
• Listing all medications you take, including blood thinners, although these usually do not need to be stopped for laser procedures
• Arranging transport home, because your vision will be temporarily blurred and you should not drive immediately afterwards
• Eating normally before the procedure — no fasting is required for routine laser
• Bringing sunglasses, as your eyes may be sensitive to light afterwards

You may receive a pressure-lowering drop, such as apraclonidine or brimonidine, shortly before the laser. This reduces the risk of a temporary pressure spike. For LPI and trabeculoplasty, a pupil-constricting drop (pilocarpine) may also be used to make the iris easier to treat.

What Happens During Laser Treatment

The exact steps vary by procedure, but the general experience is similar.

During the laser application, you may see flashes of bright light and hear soft clicking sounds. Most people feel little or nothing — sometimes a brief pinprick sensation or mild pressure. You will be asked to keep your eye still and look in a particular direction; the ophthalmologist will guide you.

Total time at the laser is usually 5 to 15 minutes per eye, depending on the procedure. The contact lens is then removed and your eye is rinsed.

For an SLT, the laser is applied to the trabecular meshwork around part or all of the drainage angle. For an LPI, a small opening is created in the upper peripheral iris, usually hidden under the upper eyelid. For cyclophotocoagulation, the probe is applied to the white of the eye rather than through a contact lens, and a stronger anaesthetic (such as an injection around the eye) may be used.

After the laser, your eye pressure is usually checked again before you leave, because some procedures can cause a temporary rise in pressure.

Recovery and Healing

Recovery from laser glaucoma procedures is usually straightforward, and most people return to normal activities the same day or the next day.

The First Few Hours

In the hours after the laser you may experience:

• Blurred vision, often improving over a few hours
• Light sensitivity
• Mild redness
• A scratchy or gritty feeling
• A mild headache or brow ache, particularly after LPI

Sunglasses can help with light sensitivity. Resting your eye for the rest of the day is sensible.

The First Week

You will usually be prescribed anti-inflammatory eye drops for several days to a week to reduce inflammation inside the eye. It is important to use them as directed. Avoid rubbing the eye. Most everyday activities — reading, screen use, gentle walking, returning to work — are fine within a day or two unless your ophthalmologist advises otherwise.

Pressure Response

The pressure-lowering effect of trabeculoplasty (SLT or ALT) develops gradually over four to six weeks. LPI, in contrast, often produces an immediate change because it physically opens the drainage angle. Cyclophotocoagulation may produce pressure changes over days to weeks as inflammation settles and fluid production stabilises.

A follow-up visit is usually scheduled within one to two weeks, and then again at four to six weeks to assess the pressure response. Your ophthalmologist will tell you whether to continue, reduce, or change your glaucoma drops based on these results.

Risks and Complications

Laser glaucoma procedures are considered low-risk, but they are not risk-free. Possible side effects and complications include:

• Temporary pressure spike in the hours after the laser, especially after trabeculoplasty. This is usually managed with medication.
• Inflammation inside the eye (iritis or uveitis), generally mild and treated with anti-inflammatory drops.
• Eye discomfort, ache, or headache, usually short-lived.
• Blurred vision for a few hours to a few days.
• Bleeding in the front of the eye, more common with LPI; this typically resolves on its own.
• Glare, halos, or a line in vision after LPI, related to the small opening in the iris. This is usually mild and tolerable.
• Inadequate pressure lowering, requiring continued drops, repeat laser, or surgery.
• Loss of effect over time, particularly with trabeculoplasty, where the effect commonly lasts one to several years.
• Inflammation, pain, or vision loss after cyclophotocoagulation, which carries a higher risk profile than trabeculoplasty or LPI and is generally reserved for more advanced disease.

Serious complications such as significant or permanent vision loss are uncommon with the more frequently performed laser procedures. Your ophthalmologist will explain the specific risks of the procedure planned for you.

Expected Outcomes

The realistic goals of laser glaucoma treatment are to lower eye pressure, reduce or simplify the use of pressure-lowering drops, and slow the progression of optic nerve damage. Laser does not restore vision that has already been lost to glaucoma.

What outcomes typically look like:

• SLT generally produces a meaningful drop in eye pressure in most people, comparable in size to the effect of a single prostaglandin eye drop. The effect tends to wear off over several years and SLT can usually be repeated.
• LPI reliably opens narrow or closed drainage angles in most eyes treated, reducing the risk of acute angle closure. It does not always remove the need for ongoing pressure-lowering treatment.
• Cyclophotocoagulation can lower pressure substantially in eyes with limited other options, but the response is more variable and the procedure may need to be repeated.

Even after a successful laser, most people with glaucoma continue some form of monitoring and many continue at least one pressure-lowering drop. Glaucoma is a chronic condition, and treatment is judged by long-term protection of the optic nerve rather than by any single pressure reading.

Life After Laser Treatment

Glaucoma care is lifelong, and laser is one chapter in that care. After your procedure, ongoing follow-up usually includes:

• Regular eye pressure measurements, often every three to six months once pressure is stable
• Visual field testing, typically once or twice a year, to detect any progression of nerve damage
• Optical coherence tomography (OCT) of the optic nerve and retinal nerve fibre layer, used to track structural changes over time
• Gonioscopy or anterior segment imaging to recheck the drainage angle, particularly after LPI or iridoplasty
• Review of medications, with adjustments based on how well pressure is controlled

If pressure rises again, your ophthalmologist may consider repeat laser, additional drops, or incisional surgery depending on the situation. Some people end up with laser as their main long-term treatment; others use it as a bridge to or alongside other therapies.

Day-to-day, there are no major restrictions after recovery. You can drive, exercise, swim, and travel as normal. Wearing sunglasses in bright light, avoiding eye rubbing, and using your prescribed drops consistently remain sensible habits.

Laser Treatment for Glaucoma in Children

Glaucoma in children is less common than in adults and is often a different disease. It can be present at birth (congenital glaucoma), develop in early childhood, or appear in adolescence (juvenile glaucoma). It can also occur secondary to other eye conditions or after eye surgery.

In children, the mainstay of treatment for congenital and many forms of childhood glaucoma is surgery on the drainage angle — procedures such as goniotomy or trabeculotomy — rather than laser. These angle surgeries are typically performed under general anaesthesia.

Laser procedures do have a role in selected paediatric situations, including:

• Laser peripheral iridotomy, in older children and adolescents with narrow or closed angles, particularly with certain inherited conditions
• Cyclophotocoagulation, in advanced or refractory childhood glaucoma when angle surgery, drops, and drainage implants have not controlled pressure

Children with glaucoma are usually managed by paediatric ophthalmologists or glaucoma specialists with paediatric experience, because the disease behaves differently from adult glaucoma and the eye is still growing. If a child has been diagnosed with glaucoma, the treatment plan, including any role for laser, will be tailored very specifically to that child by their specialist team.

Frequently Asked Questions

Will the laser hurt?

Most laser glaucoma procedures cause little or no pain. Numbing drops are used, and you may feel a brief pinprick sensation or mild pressure during the laser. Some people get a mild headache or brow ache afterwards, particularly after LPI, which usually settles quickly.

Cyclophotocoagulation, particularly traditional transscleral treatment, can be more uncomfortable, and a stronger anaesthetic is often used.

Will I still need to use eye drops after laser?

Sometimes yes, sometimes no. In some people, particularly those treated early with SLT, laser may control pressure well enough that drops can be reduced or stopped. In others, drops continue alongside the laser’s effect. Whether drops can be stopped is decided based on your pressure readings, your optic nerve, and your visual field over time.

How long does the effect last?

This depends on the procedure. The effect of SLT often lasts one to several years; in some people it lasts longer, and in others it wears off sooner. LPI usually produces a lasting opening in the iris, although ongoing pressure-lowering treatment may still be needed. Cyclophotocoagulation effects vary widely and the procedure may be repeated.

Can the laser be repeated?

SLT can often be repeated, which is one of its practical advantages. ALT has a more limited number of repeats because of the scarring it leaves. LPI is generally not repeated in the same spot, although a second opening can be made elsewhere if needed. Cyclophotocoagulation can be repeated if pressure rises again.

Will laser improve my vision?

No. Laser treatment is aimed at lowering eye pressure and protecting the optic nerve from further damage. It cannot restore vision that has already been lost to glaucoma. This is why early treatment and consistent follow-up matter so much.

Can I drive home after the procedure?

It is generally advised not to drive immediately after laser treatment because of blurred vision, light sensitivity, and the effects of the drops used. Arrange for someone to take you home.

How soon can I go back to work and normal activities?

Most people return to office work, screen use, and light activity within a day. Heavier exertion and swimming are usually fine within a few days, although your ophthalmologist will give specific guidance for your situation, especially after cyclophotocoagulation.

Does laser replace the need for surgery?

For some people with mild to moderate glaucoma, laser combined with drops controls pressure well and surgery is avoided or delayed. In more advanced disease, or when target pressure is very low, incisional surgery may still be needed. Laser and surgery are not mutually exclusive — many people have both at different points in their care.

What if my pressure does not come down after laser?

Not every eye responds to every laser procedure. If pressure does not fall enough, your ophthalmologist may add or change drops, consider a different laser procedure, or discuss incisional or minimally invasive glaucoma surgery. A non-responding laser is not a failure of treatment — it is information that helps choose the next step.

Conclusion

Glaucoma is a lifelong condition, and the goal of every treatment, including laser, is to protect the vision you have. Laser glaucoma procedures offer a quick, generally well-tolerated way to lower eye pressure without incisions or stitches, with different lasers designed for different forms of the disease — trabeculoplasty for open-angle glaucoma, iridotomy and iridoplasty for narrow or closed angles, and cyclophotocoagulation for advanced or treatment-resistant cases.

For some people, laser is the first treatment they receive. For others, it is added when drops are not enough, or used to delay or avoid surgery. In every case, it works best alongside consistent monitoring — pressure checks, visual fields, and imaging of the optic nerve — so that any change is caught early and the treatment plan can be adjusted.

The decisions about whether, when, and which laser is appropriate are made together with your ophthalmologist, based on the type and stage of your glaucoma, the anatomy of your eye, and how you have responded to other treatments so far.