Micropulse Laser Trabeculoplasty (MLT) Versus Selective Laser Trabeculoplasty (SLT) for Treatment of Open Angle Glaucoma

Glaucoma is the 2nd leading cause of blindness worldwide and affects over 2.5 million
Americans over the age of 40. It is thought that elevated intraocular pressure causes damage
to the optic nerve fibers which leads to silent vision loss in glaucoma. Therefore, the
primary approach to managing this disease process is through intraocular pressure reduction
with a) topical drops that decrease intraocular fluid production or increase fluid outflow,
b) laser therapy to the outflow structures in the eye (trabecular meshwork) to increase fluid
egression, c) or incisional surgery with or without placement of setons to create a new
pathway for fluid outflow. When medical therapy has been maximized or patients do not
tolerate topical therapy, laser trabeculoplasty is common applied to achieve further
intraocular pressure reduction. There are two types of laser therapies: argon laser
trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT). The former involves applying
laser to create outflow pathways in the trabecular meshwork (TM) and induces thermal damage
to the TM. The latter selectively applies energy which induces inflammatory restructuring of
the TM without creating a burn. Studies have shown comparable results between the two
treatment modalities with SLT offering the advantage of repeatable treatment. Studies have
also shown laser trabeculoplasty to be comparable to the effect of topical drops in
intraocular pressure reduction. Side effects for both types of laser trabeculoplasty include
post procedure intraocular pressure elevation and intraocular inflammation which is treated
with topical drops after the procedure.

This study aims to evaluate the effectiveness of micropulse laser trabeculoplasty in
intraocular pressure reduction in patients with open angle glaucoma as compared to
conventional selective laser trabeculoplasty. Secondary aims would be to determine whether
its reduction is comparable to that of topical intraocular pressure lowering drops, length of
therapeutic intraocular pressure reduction, and incidence of side effects commonly
encountered with traditional laser trabeculoplasty including intraocular inflammation and
intraocular pressure spikes.

Inclusion Criteria:

- Patients of any ange age

- Diagnosis of open angle glaucoma who have not had recent changes in their medication
regimen.

Exclusion Criteria:

- Patients with active neovascularization of the angle, angle closure glaucoma, angle
recession, or anterior uveitis