Treatment

Laser Peripheral Iridotomy

Also known as LPI, Laser Iridotomy, YAG Iridotomy, Narrow Angle Laser, Angle-Closure Laser

Updated May 16, 2026For educational purposes only. Not a substitute for medical advice. See our terms.

Bottom Line

Laser peripheral iridotomy is an office laser that makes a tiny opening in the iris. It helps prevent or treat angle-closure attacks in eyes with narrow drainage anatomy.

Laser peripheral iridotomy treats eyes where the iris can block fluid flow. The laser makes a tiny opening near the edge of the iris so fluid can move more freely 1.

It is most often used for narrow angles, primary angle closure, or after an acute angle-closure attack. A large randomized trial found a modest preventive benefit in angle-closure suspects, because many untreated eyes never progressed 2.

The procedure is quick and done at a slit lamp. Some people notice glare or a line of light afterward, and the risk depends partly on where the opening is placed 3.

How It Works

In some eyes, the iris sits close to the eye's drain, where fluid leaves the front of the eye. If fluid cannot pass easily from behind the iris to the front, the iris can bow forward and close the drain.

Laser peripheral iridotomy makes a tiny bypass opening in the iris. This can flatten the iris and lower the chance of a sudden angle-closure attack 1.

The opening is usually hidden under the upper eyelid. It does not improve glasses vision, and it does not remove cataracts.

Who It Helps

Laser peripheral iridotomy may be offered for:

  • Primary angle-closure suspect. The angle is narrow but pressure and nerve are still normal.
  • Primary angle closure. The angle is narrow with pressure rise or scarring.
  • Angle-closure glaucoma. The optic nerve has glaucoma damage.
  • After an acute attack. The laser helps prevent another attack once the eye is stable.

It may not solve narrow angles caused by a large cataract, plateau iris, scarring, or other eye disease. Those eyes may need other treatment.

Risks and Side Effects

Most side effects are mild, but risks include:

  • Temporary pressure rise. This is why pressure may be checked after the laser.
  • Redness or aching. This usually improves with drops.
  • Bleeding from the iris. A small spot of bleeding usually stops quickly.
  • Glare or line of light. Some patients notice a new light streak 3.
  • Opening closes. Rarely, the opening needs another laser.
  • Angle stays narrow. Some eyes still need cataract surgery, drops, or another laser.
Get emergency care for severe eye pain, halos with nausea, sudden vision loss, or vomiting after the procedure.

Cost and Insurance

In the United States, laser peripheral iridotomy often costs about $500-$2,000 per eye before insurance. The final bill depends on the office, facility fees, and follow-up checks.

Medical insurance usually covers the laser when an eye doctor documents narrow angles, angle closure, or an acute attack risk. You may still owe a copay, deductible, or coinsurance.

Ask the office for the procedure code, whether both eyes are planned, and whether a pressure check is billed separately.

Common Questions About Laser Peripheral Iridotomy

Most people feel pressure, a pinch, or brief snaps of light. Numbing drops are used first.

Next Steps

  1. 1Ask your doctor whether your angle narrowing is from iris blockage, cataract, or another cause.
  2. 2Confirm whether one eye or both eyes need treatment.
  3. 3Arrange a ride if your doctor uses drops that blur vision.
  4. 4Use anti-inflammatory or pressure drops exactly as directed.
  5. 5Seek emergency care for severe pain, halos with nausea, or sudden vision loss.

Find specialists for Laser Peripheral Iridotomy

Board-certified ophthalmologists who treat Laser Peripheral Iridotomy.

Browse Glaucoma specialists

Also relevant

Comprehensive