Clarifying the Optimal Application of SLT Therapy Trial
COAST
4 other identifiers
interventional
790
2 countries
29
Brief Summary
The goal of this study is to understand if SLT performed at low energy is as effective as SLT performed at standard energy, and also to see if repeating SLT at low energy once a year will prevent or delay the need for daily eye drop medications better than waiting for SLT to wear off before repeating it.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_3
Started Sep 2021
Longer than P75 for phase_3
29 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
Click on a node to explore related trials.
Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
June 27, 2021
CompletedFirst Posted
Study publicly available on registry
July 20, 2021
CompletedStudy Start
First participant enrolled
September 7, 2021
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 30, 2027
ExpectedStudy Completion
Last participant's last visit for all outcomes
August 31, 2027
October 2, 2025
September 1, 2025
5.8 years
June 27, 2021
September 26, 2025
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
12-month survival
Survival of first SLT through Month 12
12 months
48-month survival
At Month 12, subjects are randomized to repeat SLT either annually at low energy or PRN at standard energy. The proportion controlled with SLT alone at Month 48 will be compared between groups
48 months
Secondary Outcomes (3)
Mean IOP
12 months
Long-term mean IOP
12, 24, 36, and 48 months
Incidence of IOP spikes
0, 12, 24, 36, and 48 months
Study Arms (4)
Trial 1: Initial standard energy SLT
ACTIVE COMPARATORStandard energy SLT is performed as follows: beginning at 0.8 mJ, energy will be titrated up or down within the first 5-10 spots until champagne bubbles are visualized with every 2nd or 3rd spot. Energy can be titrated throughout the procedure, in response to variations in pigmentation, to ensure the appearance of champagne bubbles with every 2nd or 3rd spot throughout the full 360° treatment. Energy should be increased if no bubbles are seen with 5 consecutive spots and decreased if bubbles are seen with 5 consecutive spots.
Trial 2: Month 12 Randomization: Annual Low Energy Repeat SLT
EXPERIMENTALAt month 12, eligible subjects will be randomized to undergo repeat SLT either annually at low energy or as needed at standard energy. Low energy SLT will consist of 100 treatment spots delivered at 0.4 mJ per spot throughout the full 360° treatment, with the exception that energy can be reduced to 0.3 mJ if bubbles are seen with 5 consecutive spots and can be increased back to a maximum of 0.4mJ is no bubbles are seen with 5 consecutive spots.
Trial 2: Month 12 Randomization: As-Needed Repeat SLT at Standard Energy
ACTIVE COMPARATORAt month 12, eligible subjects will be randomized to undergo repeat SLT either annually at low energy or as needed at standard energy. Standard SLT will be performed as follows: beginning at 0.8 mJ, energy will be titrated up or down within the first 5-10 spots until champagne bubbles are visualized with every 2nd or 3rd spot. Energy can be titrated throughout the procedure, in response to variations in pigmentation, to ensure the appearance of champagne bubbles with every 2nd or 3rd spot throughout the full 360° treatment. Energy should be increased if no bubbles are seen with 5 consecutive spots and decreased if bubbles are seen with 5 consecutive spots.
Trial 1: Initial Low Energy SLT
EXPERIMENTALNote: This arm was discontinued following a planned interim analysis. Low energy SLT will consist of 100 treatment spots delivered at 0.4 mJ per spot throughout the full 360° treatment, with the exception that energy can be reduced to 0.3 mJ if bubbles are seen with 5 consecutive spots and can be increased back to a maximum of 0.4mJ if no bubbles are seen with 5 consecutive spots.
Interventions
SLT performed at low energy
SLT performed at standard energy
Eligibility Criteria
You may qualify if:
- Age 18 or older and in good health
- Each eye with one of the following qualifying diagnoses (diagnoses may differ between eyes):
- High-risk ocular hypertension (OHT): IOP \> 21 mmHg without glaucomatous optic neuropathy (excavation, diffuse or focal thinning or notching of the neuroretinal rim, visible nerve fiber layer defects, or asymmetry of the vertical cup-to-disc ratio of \>0.2 between eyes)
- Mild primary open-angle glaucoma: glaucomatous optic neuropathy, visual field mean deviation better than -6.0 dB with no points in the central 5° \<15 dB (see figure on next page)
- Moderate primary open-angle glaucoma: glaucomatous optic neuropathy, visual field mean deviation equal to or worse than -6.0 dB but no worse than -12.0 dB and no central 5° points \<15 dB or mean deviation -12.0 dB or better with 1 central 5° points \<15 dB (see figure on next page).
- Each eye with BCVA 20/200 (UK 6/60) or better
You may not qualify if:
- Use of topical IOP-lowering medications for more than 6 cumulative months at any time in the past 5 years (this is a modification implemented during active enrollment)
- Any history of IOP-lowering laser (prophylactic iridotomy not included) or surgical procedure
- Advanced POAG in either eye (worse than moderate POAG as defined above)
- Glaucoma other than POAG (including pigmentary and pseudoexfoliation glaucoma) in either eye
- Mean IOP \> 35 mmHg at either the screening or baseline visit in either eye
- Narrow or closed angle (Shaffer Grade 0, 1, or 2) in either eye
- Contraindications to SLT or any other study intervention
- Any corneal pathology that would preclude accurate assessment of IOP by Goldmann tonometry in either eye
- Any intraocular surgical procedure within the past 6 months in either eye
- Inability to attend all scheduled study visits
- Pregnant or planning to become pregnant in the next 4 years
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- University of Pittsburghlead
- National Eye Institute (NEI)collaborator
- West Virginia Universitycollaborator
Study Sites (29)
Harvard Eye Associates
Laguna Hills, California, 92653, United States
Doheny Eye Center UCLA
Pasadena, California, 91105, United States
University of California, Davis
Sacramento, California, 95817, United States
University of California, San Francisco
San Francisco, California, 94158, United States
Mile High Eye Institute
Sheridan, Colorado, 80110, United States
Clear Vue Laser Eye Center
Lakeworth, Florida, 33467, United States
Northwestern Medical Group
Chicago, Illinois, 60615, United States
Chicago Arbor Eye Institute
Orland Park, Illinois, 60467, United States
Illinois Eye Center
Peoria, Illinois, 61615, United States
Wilmer Eye Institute Johns Hopkins
Baltimore, Maryland, 21287, United States
Massachusetts Eye and Ear
Boston, Massachusetts, 02114, United States
Ophthalmic Consultants of Boston
Boston, Massachusetts, 02451, United States
Mark Latina, LLC
Reading, Massachusetts, 01867, United States
University of Michigan Kellogg Eye Center
Ann Arbor, Michigan, 48105, United States
Kresge Eye Institute Wayne State University
Detroit, Michigan, 48201, United States
New York Eye Surgery Associates
The Bronx, New York, 10469, United States
University Hospitals Eye Institute
Cleveland, Ohio, 44106, United States
Cleveland Clinic Cole Eye Institute
Cleveland, Ohio, 44195, United States
Devers Eye Institute
Portland, Oregon, 97210, United States
Eye Care Specialists
Kingston, Pennsylvania, 18704, United States
Scheie Eye Institute
Philadelphia, Pennsylvania, 19104, United States
Wills Eye Hospital
Philadelphia, Pennsylvania, 19107, United States
UPMC Eye Center
Pittsburgh, Pennsylvania, 15213, United States
Vanderbilt Eye Institute
Nashville, Tennessee, 37232, United States
Ophthalmology Associates
Fort Worth, Texas, 76102, United States
Spokane Eye Clinical Research
Spokane, Washington, 99204, United States
West Virginia University
Morgantown, West Virginia, 26505, United States
University of Wisconsin-Madison
Madison, Wisconsin, 53705, United States
Ocular Health Centre
Kitchener, Ontario, N2A0K5, Canada
Related Publications (1)
Realini T, Gazzard G, Latina M, Kass M. Low-energy Selective Laser Trabeculoplasty Repeated Annually: Rationale for the COAST Trial. J Glaucoma. 2021 Jul 1;30(7):545-551. doi: 10.1097/IJG.0000000000001788.
PMID: 33428350BACKGROUND
Related Links
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- STUDY CHAIR
Tony Realini, MD, MPH
West Virginia University
- PRINCIPAL INVESTIGATOR
Goundappa K Balasubramani, PhD
University of Pittsburgh
- PRINCIPAL INVESTIGATOR
Stephen Wisniewski, PhD
University of Pittsburgh
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 3
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- TREATMENT
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Research Associate Professor
Study Record Dates
First Submitted
June 27, 2021
First Posted
July 20, 2021
Study Start
September 7, 2021
Primary Completion (Estimated)
June 30, 2027
Study Completion (Estimated)
August 31, 2027
Last Updated
October 2, 2025
Record last verified: 2025-09
Data Sharing
- IPD Sharing
- Will share
- Shared Documents
- STUDY PROTOCOL, SAP, ICF
- Time Frame
- At study completion
- Access Criteria
- See above
All study data will be de-identified. We will invite other investigators to submit secondary data requests using the data from the study and will work with those investigators to foster additional research studies and manuscripts. The investigators agree to abide by the principles for sharing research resources as described by "Principles and Guidelines for Recipients of NIH Research Grants and Contracts on Obtaining and Disseminating Biomedical Research Resources." All publications based on the study will adhere to the NIH Public Access Policy (Notice NOT-OD-08-033). At the end of the study, all study data will be submitted for permanent archive per the notice of grant award.