YAG Laser peripheral iridotomy is widely used to treat angle-closure glaucoma. It is a safe and effective procedure that creates a hole in the iris, lowering intraocular pressure.

So, if you are considering laser treatment for glaucoma, you may be wondering how it works, how the procedure is, as well as the aftercare and risks involved.


We cannot talk about iridotomy without discussing angle-closure glaucoma. The angle is the space between the clear, outermost layer of the eye (cornea) and the colored part (iris), close where they meet near the edge of the iris. It contains the trabecular meshwork or drainage channels that direct fluid eye (aqueous humor) out of the eye.

Your eye doctor examines the angle with a test called gonioscopy. Closed-angle glaucoma is an eye disease that occurs when fluid flow between the iris and lens is obstructed. The fluid is trapped behind the pupil because of a pupillary block, the most common mechanism of angle closure.

As the pressure rises, the iris is pushed forward. So, the iris ends up covering the trabecular meshwork like a rubber stopper in a drain. With the eye’s drainage channels secondarily obstructed, the aqueous humor cannot leave your eye, so your eye pressure increases.

Increased eye pressure can lead to permanent optic nerve damage and permanent vision loss. The rise in eye pressure may occur suddenly (an acute attack of angle-closure) or gradually.

Risk factors for angle-closure include being female, Asian, have eyes shorter than average, family history, and farsightedness. The sooner the blockage of fluid flow between the iris and lens is treated, the less damage is produced.

What is Glaucoma

How Does Laser Iridotomy Works?

laser iridotomy uses a laser beam to create a microscopic hole in the outer edge of your iris. Argon laser was widely used by 1980. Since then, the neodymium: YAG laser iridotomy has proven to be safe and more effective, with fewer complications.

Whichever type of laser is used, this procedure creates a permanent passage for the aqueous humor to flow through from the posterior to the anterior chamber. Indeed, the hole helps the aqueous fluid flow from one side of the iris to the other.

The procedure also pushes the iris tissue backward, opening the angle in the majority of cases. It effectively exposes the trabecular meshwork (or internal drainage system of the eye) so that fluid outflow is enhanced.

But remember that the main purpose of this procedure is to preserve your vision, not to improve it.

Also, although the angle effectively widens after the laser treatment, expected age-related changes can alter the angle afterward. Indeed, cataract formation could close the angle again, and cataract removal may be required.

Who Is Eligible for Iridotomy?

Laser iridotomy is recommended in eyes that have angle-closure glaucoma and high eye pressure.

In eyes with closed-angle glaucoma but normal eye pressure and no optic nerve damage, it is considered a preventive treatment.

Narrow angles are the previous stage to angle-closure glaucoma, which can have a sudden, painful onset or a slow chronic course. So, it is best to prevent the damage that angle-closure glaucoma can cause by treating it with a laser iridotomy before the actual disease sets in.

This procedure treats narrow angles, chronic angle-closure glaucoma, and acute angle-closure glaucoma. However, it is not a substitute for glaucoma eye drops in most cases if you are already on medication before the procedure.

Also, you could still get chronic glaucoma despite laser procedure.


You will spend nearly 1-2 hours in our outpatient clinic. The eye is usually pretreated half an hour before the procedure with miotic drops (pilocarpine) that make the pupil small.

This medication stretches and thins your iris, much as stretching out the top surface of a drum. This makes the laser procedure easier to do safely. Also, you will receive eye drops to lower the intraocular pressure (the pressure inside your eye due to aqueous humor).

Just before the procedure, anesthetic drops/gel are placed to numb the eye’s surface so you don’t feel any pain. You may only feel slight discomfort when the laser is applied.

Then, you will then sit at a machine similar to the one used to examine your eyes. You will put your chin on a rest and wait for the doctor’s instructions. A special contact lens is then placed on the eye to perform the laser surgery. The use of the special lens keeps the eyelids open and minimizes eye movement.

Also, it allows the eye doctor to view your iris clearly so he can concentrate the laser energy and make the hole in your iris safely. Don’t worry because a gel is placed on its surface to protect the eye from being scratched or damaged by the contact lens.

The hole is created in the iris periphery, aiming at the superior quadrants between 11 and 1 o’clock. This allows the lesion to be covered by the upper eyelid.

The procedure usually takes 5-10 minutes. The YAG laser iridotomy usually makes a clicking or popping noise. You may also see bright lights and colors, like a photographer’s flash. You may experience slight discomfort, but it is mild and lasts almost no time.


The eye pressure is assessed within 45 minutes to 2 hours after the laser before discharge. Also, your doctor will verify that the hole made in the iris is large enough.

The eye may be a little red, sored, and light-sensitive for the first 24-72 hours. If you have discomfort at home, you can take OTC pain killers. There will be temporary blurriness of vision (especially at night). This is partly due to the miotic eye drops. Also, you may have a mild brow ache and headaches.

Vision is also affected by the pigment (melanin) release or inflammatory response when the hole is created. For that reason, it is probably wise to have someone drive you home after the procedure and take it easy the rest of the day. But apart from that, there are no restrictions in normal activities following the laser treatment.

You will be given steroids drops (anti-inflammatory) to be used for one to two weeks. Also, we will arrange for a follow-up appointment a few weeks later to make sure the treatment was successful.

What are the Possible Complications After an Iridotomy?

Complications after laser treatment for glaucoma are uncommon. Possible risks include increased eye pressure, bleeding at the laser site, and inflammation; these are usually temporary.

If the eye pressure rises, you will need eye drops or tablets to lower it down. This side effect occurs because immediately after iridotomy, iris pigment is released when the hole is created with the laser. It is usually transient, occurring most frequently in the first 4 hours after treatment.

The pigment can temporarily clog the drainage system. For this reason, you will be asked to wait 30-60 minutes after the procedure so that your eye pressure can be rechecked.

Closure of the iridotomy may occur, requiring further retreatment. But most laser iridotomies may remain patent years after the procedure. In up to 25% of cases, the angle may not open.

African or Asian descent usually have a thicker iris, so they could require more laser energy, medical treatment, or several touch-up sessions to create a hole of the right size.

Annoying visual symptoms, including bright lights or flashes (ghost images), or double vision in the treated eye, may rarely occur. This is caused by light passing through the hole that the laser has created.

If these vision problems occur, the brain usually will learn to adapt or ignore them over time.

Most glaucoma patients do well after laser procedure and do not experience long-term side effects. However, it is always helpful to talk with your ophthalmologist to fully understand the procedure and the expected outcome.

How Much Does Laser Iridotomy Cost?

If you want to receive a quote for laser iridotomy, please, fill in the contact form. You can send us your recent medical reports, so we can offer you the solution that best suits your needs.

You can be sure that this information will always be treated with maximum confidentiality.


Doctor Marta Mármol Díaz

Doctor Marta Mármol Díaz

Bachelor of Medicine and Surgery (Universidad Autónoma de Barcelona, 2009). Master in Pathology, Cornea and Ocular Surface (2010-2011), Master’s Degree in Retinovascular Pathology, Inflammation and Intraocular Tumours (2010-2011) from the Institut Universitari Barraquer. Specialist in Ophthalmology (2014). Training as a Fellow in the subspecialty of Orbit and Oculoplasty and actively participates in the Emergency Department of Ophthalmology of the Barraquer Ophthalmology Centre.
Languages: Catalan, Spanish, English
Association number: 45.312

Doctor Andrés Picó García

Doctor Andrés Picó García

Bachelor in Medicine and Surgery (University of Barcelona, 1984). Training in ophthalmology at the Barraquer University Institute. Internal Medical Resident (MIR) at the Barraquer Ophthalmology Centre. Grade in Optometry (Polytechnic University of Catalonia, 1997). Master in pathology and eye surgery (Universidad Autónoma de Barcelona, 1998). Doctor of Medicine and Surgery (Universidad Autónoma de Barcelona, 2007) with the qualification of Excellent “Cum Laude”.
Languages: Spanish, Catalan, English
Association number: 25.503

Doctor Francisco Ruiz Tolosa

Doctor Francisco Ruiz Tolosa

Bachelor of Medicine and Surgery (University of Barcelona, 1998). Specialist in Ophthalmology (2003). Graduated in Optometry (Universidad Autónoma de Barcelona, 1999) and specialized in anterior segment surgery and glaucoma. Coordinator of glaucoma sessions taught at the Barraquer Ophthalmology Center. He has participated in numerous studies of glaucoma medications, evaluating its effectiveness and safety, as well as different surgical techniques for the treatment of glaucoma.
Languages: Spanish, Catalan.
Association number: 34.151

External links – Bibliography

All About Glaucoma Surgery: Trabeculectomy, Sclerectomy & Ahmed Valve

Peripheral iridotomy for pigmentary glaucoma. Michelessi M, Lindsley K.Cochrane Database Syst Rev. 2016

Laser peripheral iridotomy for the prevention of angle closure: a single-centre, randomised controlled trial. He M, Jiang Y, Huang S, Chang DS, Munoz B, Aung T, Foster PJ, Friedman DS.Lancet. 2019

Role of lens extraction and laser peripheral iridotomy in treatment of glaucoma. Pose-Bazarra S, Azuara-Blanco A.Curr Opin Ophthalmol. 2018


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