AzTrials
AzTrials

Glaucoma and Ocular HypertensionPhase 3COASTNCT04967989

Clarifying the Optimal Application of SLT Therapy Trial

A Phase 3 study testing Low Energy SLT and Standard Energy SLT in people with Glaucoma and Ocular Hypertension, run by University of Pittsburgh at 29 sites in 2 countries.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
Search all trials

Trial 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. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Glaucoma and Ocular Hypertension
What is being tested?
Low Energy SLT and Standard Energy SLT
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
790 participants
Where
29 sitesin 2 countries
Study dates
7 Sep 2021to 31 Aug 2027
Phase
Phase 3
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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

Who cannot join

  • 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
Show all 11Show fewer
  • 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

Trial locations and contacts

29 sites in 2 countries. Contact the study team or a site near you to ask about taking part.

Tony Realini, MD, MPH contact

3045986926

hypotonywvu@gmail.com

29 sites in 2 countries

United States28 sites, 27 recruiting

  • University of Michigan Kellogg Eye Center

    Ann Arbor, Michigan, 48105

    Lindsay Rudberg, 734-647-9196, rulindsa@med.umich.edu

    Amanda Bicket, MD

    Recruiting

  • Wilmer Eye Institute Johns Hopkins

    Baltimore, Maryland, 21287

    Rucha Thaker, 908- 616-1807, rthaker2@jh.edu

    Pradeep Ramulu, MD

    Recruiting

  • Massachusetts Eye and Ear

    Boston, Massachusetts, 02114

    Michael Cheung, mcheung0@meei.harvard.edu

    Michael Lin, MD

    Recruiting

  • Ophthalmic Consultants of Boston

    Boston, Massachusetts, 02451

    Jessica Placher, (617) 314-2734, jplacher@eyeboston.com

    Theodor Sauer, MD

    Recruiting

  • Northwestern Medical Group

    Chicago, Illinois, 60615

    Madison Wood, (312) 695-0252, madison.wood@northwestern.edu

    Angelo Tanna, MD

    Recruiting

  • University Hospitals Eye Institute

    Cleveland, Ohio, 44106

    Sangeetha Raghupathy, 216-844-8552, Sangeetha.Raghupathy@uhhospitals.org

    Douglas Rhee, MD

    Recruiting

  • Cleveland Clinic Cole Eye Institute

    Cleveland, Ohio, 44195

    Dusica Vasic, 216-445-3840, vasicd@ccf.org

    Ang Li, MD

    Recruiting

  • Kresge Eye Institute Wayne State University

    Detroit, Michigan, 48201

    Bayan El-Haik, 313-515-5487, bayan.el-haik@wayne.edu

    Bret Hughes, MD

    Recruiting

  • Ophthalmology Associates

    Fort Worth, Texas, 76102

    Kaitlin Sinclair, 940-452-1173, ksinclair@oafw2020.com

    Brian Flowers, MD

    Recruiting

  • Eye Care Specialists

    Kingston, Pennsylvania, 18704

    Cheryl Bayley, 570-714-5915, cheryl.bayley@vipeyes.com

    Daniel Lutz, MD

    Recruiting

  • Harvard Eye Associates

    Laguna Hills, California, 92653

    Ashwini Ravichandran, 949-951-2020, aravichandran@harvardeye.com

    Ye Elaine Wang, MD

    Recruiting

  • Clear Vue Laser Eye Center

    Lakeworth, Florida, 33467

    Michelle Hill, 561-432-4141, michelle@clearvuenow.com

    Monique Barbour, MD

    Recruiting

  • University of Wisconsin-Madison

    Madison, Wisconsin, 53705

    Kelly Boyd, 608-265-4589, kmboyd@wisc.edu

    Yao Liu, MD

    Recruiting

  • West Virginia University

    Morgantown, West Virginia, 26505

    Athena Echols, LPN, 304-598-6977, athena.sparks@wvumedicine.org

    Tony Realini, MD, MPH

    Recruiting

  • Vanderbilt Eye Institute

    Nashville, Tennessee, 37232

    Marybeth Carter, 616-936-1639, marybeth.l.carter@vumc.org

    Rachel Kuchtey, MD

    Recruiting

  • Chicago Arbor Eye Institute

    Orland Park, Illinois, 60467

    Lorene Rafol, 708-249-1026, lorenerafol@arboreyecare.com

    Richard Quinones, MD

    Recruiting

  • Doheny Eye Center UCLA

    Pasadena, California, 91105

    Mayra Raygoza, (626) 817-4747 ext. 19093, MRaygoza@mednet.ucla.edu

    Judy L Chen, MD

    Recruiting

  • Illinois Eye Center

    Peoria, Illinois, 61615

    Lori Hendershott, 309-213-0664, lhendershott@illinoiseyecenter.com

    Sachin Kalarn, MD

    Recruiting

  • Scheie Eye Institute

    Philadelphia, Pennsylvania, 19104

    Criston Young, 856-519-8295, Criston.Young@pennmedicine.upenn.edu

    Ahmara Ross, MD

    Recruiting

  • Wills Eye Hospital

    Philadelphia, Pennsylvania, 19107

    Meskerem Divers, 215-825-4712, MDivers@willseye.org

    Lauren Hock, MD

    Recruiting

  • UPMC Eye Center

    Pittsburgh, Pennsylvania, 15213

    Active, not recruiting

  • Devers Eye Institute

    Portland, Oregon, 97210

    Jack Rees, 503-413-8495, jrees@deverseye.org

    Robert Kinast, MD

    Recruiting

  • Mark Latina, LLC

    Reading, Massachusetts, 01867

    Ann Gardikas, 781-942-9876, anngardikas76@gmail.com

    Mark Latina, MD

    Recruiting

  • University of California, Davis

    Sacramento, California, 95817

    Leslie Valverde, 916-734-6302, ldlopez@ucdavis.edu

    James Brandt, MD

    Recruiting

  • University of California, San Francisco

    San Francisco, California, 94158

    Ethan Liang, (415) 525-9890, Ethan.Liang@ucsf.edu

    Ying Han, MD

    Recruiting

  • Mile High Eye Institute

    Sheridan, Colorado, 80110

    Michelle Lopez Galindo, (303) 482-1300 ext. 106, Michelle@mhei.com

    Zachary Vest, MD

    Recruiting

  • Spokane Eye Clinical Research

    Spokane, Washington, 99204

    Dylan Waidelich, 509-623-9768, dwaidelich@spokaneeye.com

    Rory Allar, MD

    Recruiting

  • New York Eye Surgery Associates

    The Bronx, New York, 10469

    Krystina Tavarez-Feliciano, 347-860-4474, kfeliciano@nyeye.com

    Nathan Radcliffe, MD

    Recruiting

Other trials in United States

Canada1 site

  • Ocular Health Centre

    Kitchener, Ontario, N2A0K5

    Active, not recruiting

Other trials in Canada

About this study

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.

Being tested
Low Energy SLT, Standard Energy SLT
Keywords
glaucoma, selective laser trabeculoplasty, clinical trial
Medical subject headings
Glaucoma, Ocular Hypertension

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Low Energy SLTProcedure or surgery

    SLT performed at low energy

  • Standard Energy SLTProcedure or surgery

    SLT performed at standard energy

Study groups in NCT04967989
Study groupRoleWhat they receive
Trial 1: Initial standard energy SLTActive 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.
Receives: Procedure: Standard Energy SLT
Trial 2: Month 12 Randomization: Annual Low Energy Repeat SLTExperimentalAt 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.
Receives: Procedure: Low Energy SLT
Trial 2: Month 12 Randomization: As-Needed Repeat SLT at Standard EnergyActive 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.
Receives: Procedure: Standard Energy SLT
Trial 1: Initial Low Energy SLTExperimentalNote: 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.
Receives: Procedure: Low Energy SLT

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. 12-month survival

    Survival of first SLT through Month 12

    Measured: 12 months

  2. 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

    Measured: 48 months

Secondary outcomes (3)

  1. Mean IOP

    Mean IOP at month 12

    Measured: 12 months

  2. Long-term mean IOP

    Mean IOP at each study visit

    Measured: 12, 24, 36, and 48 months

  3. Incidence of IOP spikes

    IOP spikes > 5 mmHg on day of SLT

    Measured: 0, 12, 24, 36, and 48 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Jul 2021
  2. Study start7 Sep 2021
  3. Primary completion30 Jun 2027 (estimated)
  4. Study completion31 Aug 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
The COAST trial underwent a design modification in response to a planned interim analysis. The original and current designs are described here. Initial Design: Subjects are randomized at study entry to initial SLT at standard or low energy. Subjects who reach Month 12 without discontinuing study treatment are randomized a second time to annual low-energy repeat SLT or as-needed standard energy repeat SLT. There are 2 arms in the first 12 months of the study and 2 arms in Months 13-48. Current deign: Subjects receive standard at SLT at study entry. Subjects who reach Month 12 without discontinuing study treatment are randomized to annual low-energy repeat SLT or as-needed standard energy repeat SLT. There are 2 arms in the first 12 months of the study and 2 arms in Months 13-48.
Masking
None (open label)
Enrolment
790 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04967989
Sponsor's protocol ID
STUDY21060171
Other IDs
2UG1EY031651-06, UG1EY031651, STUDY21080018
Acronym
COAST
Status last verified
Aug 2026
First submitted
27 Jun 2021
Last updated
14 Aug 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: 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.

Publications

  • 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.

    PubMed 33428350

  • Realini T, Balasubramani G, Kenkre T, Wolsk J, Kass MA, Gazzard G, Wisniewski SR; COAST Study Investigators. Design and Baseline Characteristics of Participants in the Clarifying the Optimal Application of Selective Laser Trabeculoplasty (SLT) Therapy (COAST) Trial 1. J Glaucoma. 2026 Aug 1;35(8):e112-e122. doi: 10.1097/IJG.0000000000002717. Epub 2026 Mar 23.

    PubMed 41886500

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Low Energy SLT and Standard Energy SLT in people with Glaucoma and Ocular Hypertension, run by University of Pittsburgh at 29 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 14 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 29 sites in United States, Canada. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Tony Realini, MD, MPH (3045986926, hypotonywvu@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

12-month survival (time frame: 12 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04967989, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 14 Aug 2026.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in