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

• ClinicalTrials.gov Identifier: NCT01956942
• Recruitment Status: Completed
• First Posted: October 8, 2013
• Last Update Posted: March 5, 2018
• Sponsor: David Belyea
• Information provided by (Responsible Party): David Belyea, George Washington University

Study Description

Brief Summary:

The purpose of this study is to evaluate the effectiveness of a new laser (called Micropulse Laser Trabeculoplasty or MLT) in the treatment of glaucoma compared to the conventional laser presently used which is called selective laser trabeculoplasty or SLT. Both lasers (SLT and MLT) are used as standard of care in the treatment of open angle glaucoma.

Condition or disease	Intervention/treatment	Phase
Open Angle Glaucoma	Device: Micropulse Laser Trabeculoplasty; Device: Selective Laser Trabeculoplasty	Phase 4

Detailed Description:

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.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 81 participants
• Allocation: Randomized
• Intervention Model: Parallel Assignment
• Masking: None (Open Label)
• Primary Purpose: Treatment
• Official Title: Phase IV Study of Micropulse Laser Trabeculoplasty Versus Selective Laser Trabeculoplasty for Treatment of Open Angle Glaucoma
• Study Start Date: August 2013
• Actual Primary Completion Date: July 2017
• Actual Study Completion Date: July 24, 2017

Arms and Interventions

Arm	Intervention/treatment
Experimental: Micropulse Laser Trabeculoplasty; Patient's randomized to MLT would be treated with the following settings: 300 micron spot size, 0.3 second duration, 15% duty cycle, and 1000 milliWatt power. They would be treated with confluent laser spots across the entire 360 degrees of the trabecular meshwork. Each patient would receive pre-treatment with a drop on iopidine or brimonidine to prevent post-operative intraocular pressure (IOP) spikes as per standard pre-laser trabeculoplasty protocol.	Device: Micropulse Laser Trabeculoplasty; Other Names: MLT; Laser
Active Comparator: Selective Laser Trabeculoplasty (SLT); Patient's randomized to SLT would be treated with the following settings: 400 micron spot size, 0.3 second duration, and 1.00 milliWatt (mW) power. They would be treated with confluent laser spots across the entire 360 degrees of the trabecular meshwork. Each patient would receive pre-treatment with a drop on iopidine or brimonidine to prevent post-operative IOP spikes as per standard pre-laser trabeculoplasty protocol.	Device: Selective Laser Trabeculoplasty; Other Names: SLT; Laser

Outcome Measures

Primary Outcome Measures :

1. Intraocular pressure reduction [ Time Frame: within 6 weeks to 3 months after the laser procedure is completed ]
   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 Outcome Measures :

1. incidence of intraocular inflammation [ Time Frame: within 6 weeks following the laser procedure ]
   The incidence of side effects commonly encountered with traditional laser trabeculoplasty including intraocular inflammation will be measured and compared between both lasers (SLT vs. MLT).

Eligibility Criteria

• Ages Eligible for Study: Child, Adult, Older Adult
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Criteria

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

Contacts and Locations

Locations

United States, District of Columbia

George Washington University Medical Faculty Associates

Washington, District of Columbia, United States, 20037

Sponsors and Collaborators

David Belyea

Investigators

• Principal Investigator: David Belyea, MD; George Washington University

More Information

Publications:

Detry-Morel M, Muschart F, Pourjavan S. Micropulse diode laser (810 nm) versus argon laser trabeculoplasty in the treatment of open-angle glaucoma: comparative short-term safety and efficacy profile. Bull Soc Belge Ophtalmol. 2008;(308):21-8.

Juzych MS, Chopra V, Banitt MR, Hughes BA, Kim C, Goulas MT, Shin DH. Comparison of long-term outcomes of selective laser trabeculoplasty versus argon laser trabeculoplasty in open-angle glaucoma. Ophthalmology. 2004 Oct;111(10):1853-9.

Fea AM, Bosone A, Rolle T, Brogliatti B, Grignolo FM. Micropulse diode laser trabeculoplasty (MDLT): A phase II clinical study with 12 months follow-up. Clin Ophthalmol. 2008 Jun;2(2):247-52.

• Responsible Party: David Belyea, Principal Investigator, George Washington University
• ClinicalTrials.gov Identifier: NCT01956942
• Other Study ID Numbers: 041310
• First Posted: October 8, 2013
• Last Update Posted: March 5, 2018
• Last Verified: September 2013

Keywords provided by David Belyea, George Washington University:

GLAUCOMA; MICROPULSE; LASER; TRABECULOPLASTY; OPEN ANGLE; INTRAOCULAR PRESSURE

Additional relevant MeSH terms:

Glaucoma; Glaucoma, Open-Angle; Ocular Hypertension; Eye Diseases