Argon Laser Trabeculoplasty (ALT)
Argon Laser Trabeculoplasty (ALT) is an advanced laser technique used to treat open-angle glaucoma. The procedure has been used for many years and continues to be a powerful tool in the treatment of certain types of glaucoma. ALT is often recommended when medical therapy alone is insufficient in controlling pressure. It has recently been advocated by some as primary therapy in the treatment of glaucoma, especially for those patients who have contraindications to glaucoma medications or, for any reason, are unable to use eye drops.
The laser delivers a precise beam of light to the drainage channels inside the eye. Each burst of laser energy unblocks these drainage channels. Subsequent contraction around the burns further 'pulls' or 'stretches' the microscopic channels, increasing drainage of fluid and decreasing pressure. In most cases, 180 degrees of the trabecular meshwork is treated, which typically requires about 40 to 50 laser applications.
The procedure - further details
The laser treatment is performed in a consulting room. Admission to the Day Surgery Unit is not required. On arrival you will have drops instilled into your eye to constrict the pupil and reduce the pressure. These take 15 minutes to work. Local anaesthetic drops are used and a laser lens is placed on your eye to allow for microscopic focusing of the laser beam. The actual laser procedure takes only 5 minutes. Your eye pressure will be taken after 2 hours to ensure there is no elevation which may require more drops or tablets.
To reduce any inflammation, anti-inflammatory drops are used 4 times a day for one week in the treated eye. Keep the bottle as it can be used after subsequent treatments. Only one third to one half of the drainage angle is lasered at one session to prevent a pressure spike, so there are usually 2 to 3 sessions per eye. Continue with all your regular glaucoma drops to both eyes unless instructed to cease them.
FAQ's
Does an ALT Procedure Reverse Glaucoma? Is it Always Effective?
In general, glaucoma is not reversed, or cured, by any procedure or medication. However, an ALT often works like a powerful medication, in terms of pressure reduction, without the potential side effects of medicines. Therefore, it may be used alone or in combination with medicines to treat glaucoma. The procedure isn’t always effective, although it will be effective in pressure reduction in the great majority of cases
Does the Pressure Lowering Effect with an ALT last a Lifetime?
In most cases, the pressure lowering effect with an ALT will last 3 to 5 years. If the initial treatment is effective, a second ALT, in which the opposite half of the trabecular meshwork is treated, may be appropriate.
Are there any Complications with an ALT?
The risks with an ALT procedure are rare, and when they do occur, are even more rarely serious. In general, the risks include post-operative inflammation, pressure spikes, and worsening of glaucoma. The latter complication is likely to be due to the underlying disease, and not the ALT procedure itself.
Is an ALT Procedure More Likely to be Helpful for Certain Types of Glaucoma?
Yes. ALT seems to work best in patients with primary open angle glaucoma, pseudoexfoliation (exfoliation) syndrome, and pigmentary dispersion syndrome (pigmentary dispersion glaucoma). It is also likely to be more efficacious for patients who have significant pigmentation in the trabecular meshwork. This latter characteristic is determined by the ophthalmologist when examining the angle of the eye, in a diagnostic procedure called gonioscopy.
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