Laser iridectomy

A clear fluid constantly forms inside the eye, nourishing the tissues and draining through the drainage area between the iris and cornea. If this angle becomes too narrow, pressure can increase suddenly or gradually. Laser iridectomy creates an additional pathway for the fluid through a small opening in the peripheral part of the iris.

The laser procedure is more accurately termed "peripheral iridotomy": the laser creates an opening without removing tissue. This method helps eliminate pupillary block, but it does not cure all forms of glaucoma or restore vision already lost due to optic nerve damage.

We'll explore who is suitable for the procedure, how the doctor evaluates the anterior chamber angle, and what happens during the session. We'll also discuss pressure control, possible visual effects, and cases where a single laser hole isn't enough.

How does angle closure occur?

Aqueous humor (intraocular fluid) forms behind the iris, passes through the pupil, and drains through the drainage network in the angle of the anterior chamber. In pupillary block, the fluid has difficulty flowing forward, putting pressure on the iris from behind and displacing it toward the drainage area.

If the angle closes suddenly, pressure rapidly increases. Severe eye and head pain, redness, blurred vision, rainbow-colored halos around light, nausea, and vomiting occur. If these symptoms occur, seek immediate ophthalmological care rather than waiting for a scheduled laser appointment.

The closure can develop gradually, without a significant attack. Prolonged contact between the iris and the drainage network can cause adhesions and damage to the optic nerve. Iridotomy eliminates the pupillary block component, but does not resolve the adhesions that have already formed.

Who might need the procedure?

Iridotomy is performed for angle-closure glaucoma and narrow-angle glaucoma with a high risk of closure. After an attack in one eye, the procedure is often considered for the other eye. The doctor determines the timing after assessing the acute condition.

Indications:

• confirmed pupillary block at angle closure;

• suffered an acute attack after a drop in pressure;

• high risk of attack in the second eye;

• individual secondary forms of angle closure with pupillary block;

• the need for pupil dilation or other procedure when the angle is dangerously narrow.

Iridotomy is usually ineffective in open-angle glaucoma. It may be insufficient in cases of iris plateau, large lens, or cicatricial angle closure.

How is the eye examined?

Before treatment, pressure is measured and the anterior segment of the eye and optic nerve are examined. Gonioscopy (examination of the drainage angle through a special lens) reveals its width and the presence of adhesions. Sometimes the visual field is examined.

In an acute attack, pressure is first reduced with medication, as the swollen cornea interferes with beam guidance. Once vision improves, an iridotomy is performed.

An examination of the optic nerve and visual field reveals whether glaucoma has developed. Even after the angle has opened, some patients require drops to control their pressure.

Before the procedure, please inform your doctor about any medications, allergies, and previous surgeries. Continue using the drops as prescribed. Vision may become blurred after the laser, so it's best to arrange your transportation home.

How is laser iridotomy performed?

Drops are instilled into the eye to constrict the pupil and provide local anesthesia. A contact lens is placed on the surface, focusing the beam and holding the eyelids in place. The doctor selects a peripheral area of ​​the iris, usually covered by the upper eyelid, and creates an opening with a series of pulses.

The patient sees flashes and may feel a tingling sensation. Sometimes, slight bleeding from the iris occurs. After the session, the opening is checked and the pressure is measured at an agreed-upon interval.

Important! The terms "laser iridectomy" and "laser iridotomy" are often used interchangeably, but the latter is technically more accurate. Iridectomy refers to the removal of a portion of the iris and is typically referred to as a surgical procedure, while a laser creates an opening without removing tissue.

What is monitored after the procedure?

After the laser procedure, blurred vision, photophobia, and moderate pain are possible. Blood pressure sometimes increases temporarily, so it is re-measured. The ophthalmologist determines the appropriate eye drop regimen.

Possible complications include:

• short-term increase in intraocular pressure;

• inflammation of the anterior segment of the eye;

• slight bleeding from the iris;

• glare, streaking, or double vision;

• damage to the cornea or lens;

• narrowing or closing of the hole with the need for repeat laser treatment.

Even with an open aperture, the angle may remain narrow, and glaucoma may progress. Therefore, the angle, pressure, optic nerve, and visual field are monitored. Do not stop using the drops on your own.

During a follow-up examination, the hole is checked to ensure it remains open, and the position of the iris is assessed using gonioscopy. A visible hole does not necessarily indicate normal fluid drainage.

Mild sensitivity to light usually gradually diminishes. Severe or increasing pain, sudden deterioration of vision, nausea, severe redness, and recurring rainbow-colored halos require urgent blood pressure measurement and examination.

If the hole has closed, the laser can be repeated. If the closure persists, iridoplasty, lens removal, medication, or surgery are considered. The choice depends on the anatomy of the eye.

Preventative treatment reduces the risk but does not provide complete protection against glaucoma. Monitoring can detect increases in pressure before vision deteriorates.

Сonclusion

Laser peripheral iridotomy creates an additional pathway for aqueous humor and reduces pupillary block. It is used when the angle is closed or there is a significant risk of this condition, as confirmed by examination.

The procedure does not restore damaged optic nerve fibers and does not replace treatment for other glaucoma mechanisms. Outcomes are assessed based on iris position, angle width, and pressure control. Immediate visual clarity is not a criterion for success.

After laser treatment, monitoring continues: the opening may narrow, and the angle may remain closed. Knowing the symptoms helps promptly seek additional treatment.