Trabeculoplasty is a laser treatment for primary
open-angle glaucoma. The laser is used to treat the trabecular meshwork, through which
the aqueous humor drains. In this procedure: – The eye is numbed with eye drops.
– A special laser lens is placed on the eye to help control the direction of the laser
beams. – The laser burns a small area in the trabecular
meshwork, opening up the drainage canal. – About 50 spots over 180 degrees of the meshwork
circle are treated in one therapy. The original laser trabeculoplasty procedure
applies argon laser of 514nm wavelength on half of the meshwork circle in one treatment.
Although a second treatment can be performed on the other half of the circle, the procedure
is generally not repeatable as it causes extensive scarring of the trabecular meshwork.
The newer technique — Selective Laser Trabeculoplasty or SLT — uses a solid-state laser of 532nm
wavelength. The pulse energy of SLT is about 100 times lower than the traditional argon
laser trabeculoplasty. SLT selectively targets pigmented cells while leaving the rest of
the trabecular meshwork tissue intact. For this reason, it can be applied to 360 degrees of the meshwork in one treatment and is considered safe to be repeated.
In term of efficiency, the two techniques return similar results in lowering intraocular
pressure. Laser trabeculoplasty treatment is effective in about 75% of patients. The
effect may take a few weeks to kick in and can last for several years.