PI Laser (Peripheral Iridotomy)

A Tiny Opening That Prevents a Dangerous Rise in Eye Pressure

In some eyes, the natural drainage angle between the iris and the cornea is very narrow or at risk of closing completely. When this happens, the pressure inside the eye can rise suddenly and dramatically — a condition called acute angle-closure glaucoma, which is a genuine medical emergency. Peripheral Iridotomy uses a precise laser to create a tiny opening in the iris, allowing fluid to flow freely and preventing this dangerous pressure spike from ever occurring.

What Is Peripheral Iridotomy?

Peripheral Iridotomy — or PI — is a laser procedure that creates a very small hole near the outer edge of the iris, the coloured part of the eye. This opening creates an alternative route for the aqueous fluid inside the eye to flow between the chambers of the eye, bypassing the narrow drainage angle. By equalising the pressure on both sides of the iris, the procedure prevents the iris from being pushed forward and blocking the drainage angle entirely — which is what causes acute angle-closure glaucoma.

Who Needs This Procedure?

• Patients with a narrow anterior chamber angle identified during routine examination
• Those diagnosed with narrow-angle or angle-closure glaucoma
• Patients who have had an acute angle-closure attack in one eye
• Those about to undergo certain procedures that could trigger angle closure
• Patients with a family history of angle-closure glaucoma and narrow angles

What Happens During the Procedure?

Step 1 — Eye Drops

Drops are applied to constrict the pupil and make the iris easier to treat, along with a pressure-lowering drop to reduce the risk of a post-laser pressure spike.

Step 2 — Anaesthetic Drops

Numbing drops are applied so the contact lens used during the procedure is comfortable and the laser application is painless.

Step 3 — The Laser

A special contact lens is placed on your eye and the laser is directed at the peripheral iris. A very small opening is created with a few precise laser pulses. You may see a brief bright flash and feel a very mild stinging sensation, but the procedure is very well-tolerated.

Step 4 — Done

The whole procedure takes only five to ten minutes. You remain in the clinic for a short observation period afterward to confirm your eye pressure has not risen significantly, then you can go home.

After the Procedure

Some blurring and mild light sensitivity are normal for a few hours. You will be prescribed anti-inflammatory eye drops for a few days. A follow-up appointment is arranged to check the iridotomy is patent — meaning the opening is clear and functioning — and that your drainage angle is adequately widened.

Why Patients Trust RGC Eye Hospital

• Experienced glaucoma specialists skilled in laser iridotomy techniques
• Modern YAG laser systems for precise, safe, and effective treatment
• Careful post-procedure monitoring to confirm the procedure has achieved the desired result
• Clear advice on what to expect and when to seek help if needed