YAG laser iridotomy is a specialized ophthalmic procedure used primarily to treat or prevent a specific type of glaucoma known as angle-closure glaucoma (also called closed-angle or narrow-angle glaucoma). This laser treatment involves creating a tiny hole in the iris, the colored part of the eye, using a YAG (yttrium-aluminum-garnet) laser. The purpose of this small opening is to improve fluid drainage within the eye and thereby reduce intraocular pressure (IOP), helping to preserve vision and prevent optic nerve damage.

This procedure is often quick, minimally invasive, and effective in treating patients who are at risk of sudden and severe increases in eye pressure. Understanding YAG laser iridotomy requires some background on how the eye works and how angle-closure glaucoma develops.

Anatomy of the Eye and Aqueous Humor Flow

The eye is a fluid-filled organ. One important fluid inside the eye is the aqueous humor, which nourishes the eye and maintains pressure. It is produced by the ciliary body behind the iris and flows through the pupil into the anterior chamber, the front part of the eye between the cornea and the iris. From there, it drains through the trabecular meshwork, located at the angle where the iris meets the cornea.

In a healthy eye, this drainage system maintains a balanced pressure. If the fluid cannot drain properly, pressure inside the eye builds up—this is what happens in glaucoma.

What is Angle-Closure Glaucoma?

Angle-closure glaucoma occurs when the drainage angle in the eye becomes blocked or too narrow, restricting the outflow of aqueous humor. This can lead to a sudden and dangerous spike in intraocular pressure, damaging the optic nerve and potentially causing permanent vision loss if not treated promptly.

There are two main types:

Acute angle-closure glaucoma: A medical emergency with sudden onset of symptoms like severe eye pain, headache, nausea, blurred vision, and halos around lights.
Chronic angle-closure glaucoma: Develops more slowly and can cause gradual vision loss without obvious symptoms.

In many cases, patients may not show symptoms until significant damage has occurred. This is why YAG laser iridotomy is often performed as a preventive measure in people identified as having anatomically narrow angles during routine eye exams.

How YAG Laser Iridotomy Works

The goal of YAG laser iridotomy is to create an alternative pathway for aqueous humor to flow from the posterior to the anterior chamber. The laser makes a small hole in the peripheral iris, bypassing the natural pupil opening.

This tiny hole serves as a “pressure release valve,” allowing the fluid to move more freely and equalize pressure between the back and front of the eye. As a result, it helps to open the drainage angle and reduce the risk of angle-closure glaucoma.

Indications for YAG Laser Iridotomy

YAG laser iridotomy is typically recommended in the following cases:

Primary angle-closure suspect (PACS): The angle appears narrow on examination but no damage or pressure increase has occurred yet.
Primary angle-closure (PAC): The angle is closed, and there is an increase in intraocular pressure, but no optic nerve damage.
Primary angle-closure glaucoma (PACG): The angle is closed with optic nerve damage and visual field loss.
Acute angle-closure attack: As an emergency treatment after initial pressure-lowering medications.
Secondary angle-closure: Caused by other eye conditions or medications that result in angle narrowing or closure.

The Procedure: What to Expect

YAG laser iridotomy is usually performed in an outpatient setting and takes only a few minutes per eye. Here’s what typically happens:

Pre-procedure preparation:

The eye is numbed with anesthetic drops.
A medication (such as pilocarpine) is given to constrict the pupil and stretch the iris, making the procedure easier.

Laser procedure:

The patient sits at a laser machine, similar to a slit-lamp.
A special contact lens may be placed on the eye to focus the laser and prevent blinking.
The doctor uses the YAG laser to make a small hole near the top of the iris (usually under the upper eyelid to minimize glare).

Post-procedure care:

Eye pressure is checked about an hour afterward.
Anti-inflammatory eye drops may be prescribed for a few days.
Follow-up visits are necessary to monitor pressure and healing.

The entire process is generally painless, though some patients report a brief sharp sensation or discomfort during the laser pulses.

Benefits of YAG Laser Iridotomy

Prevents acute angle-closure attacks, which can lead to rapid vision loss.
Improves fluid drainage, reducing intraocular pressure.
Minimally invasive with no incisions.
Performed quickly and typically on an outpatient basis.
Little to no recovery time, with most patients resuming normal activities the same day.

Risks and Side Effects

Though considered safe, YAG laser iridotomy does carry some risks and side effects:

Mild eye discomfort or redness shortly after the procedure.
Transient rise in intraocular pressure, typically monitored post-treatment.
Blurred vision or seeing spots/floaters temporarily.
Inflammation, usually controlled with eye drops.
Failure to lower pressure or open the angle, in which case additional treatments may be required.
Dysphotopsia (seeing a line or glare from the iridotomy hole), though rare.

Complications are infrequent, and the benefits in high-risk patients usually outweigh the risks.

Success Rate and Follow-Up

YAG laser iridotomy is successful in preventing angle-closure attacks in the majority of cases. However, it may not completely cure glaucoma or eliminate the need for ongoing treatment. Some patients still require eye drops or additional surgeries to maintain pressure control.

Regular follow-up visits with an ophthalmologist are crucial to monitor intraocular pressure, ensure the iridotomy remains open, and check for signs of glaucoma progression.

Conclusion

YAG laser iridotomy is a crucial procedure in the management and prevention of angle-closure glaucoma. By creating a tiny drainage hole in the iris, it helps equalize pressure in the eye and improves fluid outflow, significantly reducing the risk of acute attacks and vision loss.

This simple, outpatient procedure is a powerful tool in the early intervention of a potentially blinding disease. For individuals at risk or diagnosed with narrow angles, YAG laser iridotomy offers a safe, effective solution to preserve vision and maintain long-term ocular health.