Argon laser trabeculoplasty is a surgical technique that uses a laser to reduce intraocular pressure (IOP), the pressure in the eye. It’s employed in treating some types of glaucoma, an eye disease that damages the optic nerve which transmits visual messages to the brain. The disease develops due to a prolonged high IOP and causes permanent vision loss. Early diagnosis and treatment can prevent blindness.

High IOP occurs when the aqueous humor, the inner eye fluid, fails to flow out properly due to an anomaly in the eye’s drainage system. In the ALT procedure, the eye surgeon applies a laser beam to the drainage channels, which improves the outflow of the fluid and reduces the IOP. It may help prevent further damage to the optic nerve and vision loss. 

The technique is used where medication, including pills and eye drops, produce adverse side effects or are unable to lower the IOP sufficiently. However, because of a loss in efficacy over time, the patient may need a different treatment or may need to repeat the procedure again in the future.

Also Known As

  • ALT

Preparation and Expectation Before Surgery

The patient can ask questions about the surgery during the consultation before the treatment. The surgeon will explain the procedure, benefits, risks and address any concerns. S/he will also take the complete medical history and conduct a comprehensive eye examination. The patient should inform the surgeon about all medications and supplements that they may be using and s/he will advise on whether or not to continue with the routine.

In some cases, the patient may have to undergo a preparatory procedure such as a laser iridoplasty or a laser peripheral iridectomy, before the ALT surgery. It helps deepen and enable better visualization of the eye’s drainage angle.

The surgeon will give instructions on how to prepare for the surgery, which may include not wearing eye makeup on the day, and bringing a pair of glasses for contact lens users. The patient should also be accompanied with someone or arrange for a ride home after the procedure.

Types, Purpose & Procedure

The surgeon will apply eye drops which lower the IOP about 30 to 60 minutes before the surgery, to minimize the IOP upsurge after treatment. During the operation, s/he will numb the patient’s eye using topical eye drops and place a gonioscopic contact lens on the eye surface, allowing visualization of the drainage angle. S/he will then apply laser spots to the trabecular meshwork that forms the eye’s drainage channel. Each area is only treated once to prevent scar formation in the drainage angle.

The procedure can be conducted in the surgeon’s office or an outpatient surgery center in about ten minutes. After about one hour, the IOP is measured to ensure that it’s stable and the patient can go home on the same day.

Risks & Complications

The risks of the ALT procedure may include:

  • Pain
  • Inflammation of the iris
  • Sharp rise in IOP within one to four hours after the operation

The most common side effects are blurriness, mild soreness and tenderness. The patient should see the ophthalmologist if they experience pain, discomfort, or the blurriness persists, for more than 24 hours.

ALT surgery complications are rare and include:

  • Decreased vision
  • The cornea and the iris sticking together causing drainage angle blockage
  • Brief and self-limited cloudiness of the cornea (the clear covering over the iris)

After Care, Recovery & Outcome

The surgeon will prescribe medications to control the IOP and prevent a post-operative spike. S/he will also prescribe topical steroids, which are used for up to a week after treatment to prevent the inflammation of the iris. The patient will receive direction on whether or not to continue with the glaucoma medication.

The surgeon will give aftercare instructions, including activities the patient should avoid. In most cases, the patient can resume all their usual activities without restrictions. A follow-up schedule will also be provided to regularly monitor the patient’s IOP.

A few days or weeks after the treatment, the humor flow should improve, leading to a decrease in the IOP. It can take three to six weeks, or longer, for the procedure to take full effect. It’s essential to keep in mind that even if the ALT surgery is successful, its effect is usually not permanent. It can control IOP for three to five years.