Skip to main content
TTrialFinderData
TrialFinderData is for informational purposes only and does not provide medical advice. Always talk to your doctor.

Updated May 2026 · ClinicalTrials.gov

RECRUITINGPhase 3INTERVENTIONAL

Clarifying the Optimal Application of SLT Therapy Trial

Clarifying the Optimal Application of SLT Therapy Trial (NCT04967989) is a Phase 3 interventional studying Glaucoma and Ocular Hypertension, sponsored by University of Pittsburgh. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

Important: This information is not medical advice. Talk to your doctor about whether a clinical trial is right for you.

About This Trial

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.

What Stage of Research Is This?

Phase 3 trials confirm efficacy and safety in large patient groups (often 300–3,000+) and form the evidence base for an FDA approval submission. For Glaucoma and Ocular Hypertension, Phase 3 studies typically randomize participants between the investigational treatment and either a placebo or current standard of care. A successful Phase 3 result is the threshold most treatments need to clear before regulatory approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

A target enrollment of 790 participants makes this a sizable late-stage trial. Studies in this range typically have enough power to detect clinically meaningful differences from a comparator and to characterize less-common side effects.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Age 18 or older and in good health 2. Each eye with one of the following qualifying diagnoses (diagnoses may differ between eyes): 1. 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) 2. 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) 3. 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). 3. Each eye with BCVA 20/200 (UK 6/60) or better Who Should NOT Join This Trial: 1. 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) 2. Any history of IOP-lowering laser (prophylactic iridotomy not included) or surgical procedure 3. Advanced POAG in either eye (worse than moderate POAG as defined above) 4. Glaucoma other than POAG (including pigmentary and pseudoexfoliation glaucoma) in either eye 5. Mean IOP \> 35 mmHg at either the screening or baseline visit in either eye 6. Narrow or closed angle (Shaffer Grade 0, 1, or 2) in either eye 7. Contraindications to SLT or any other study intervention 8. Any corneal pathology that would preclude accurate assessment of IOP by Goldmann tonometry in either eye 9. Any intraocular surgical procedure within the past 6 months in either eye 10. Inability to attend all scheduled study visits 11. Pregnant or planning to become pregnant in the next 4 years Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language
Inclusion Criteria: 1. Age 18 or older and in good health 2. Each eye with one of the following qualifying diagnoses (diagnoses may differ between eyes): 1. 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) 2. 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) 3. 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). 3. Each eye with BCVA 20/200 (UK 6/60) or better Exclusion Criteria: 1. 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) 2. Any history of IOP-lowering laser (prophylactic iridotomy not included) or surgical procedure 3. Advanced POAG in either eye (worse than moderate POAG as defined above) 4. Glaucoma other than POAG (including pigmentary and pseudoexfoliation glaucoma) in either eye 5. Mean IOP \> 35 mmHg at either the screening or baseline visit in either eye 6. Narrow or closed angle (Shaffer Grade 0, 1, or 2) in either eye 7. Contraindications to SLT or any other study intervention 8. Any corneal pathology that would preclude accurate assessment of IOP by Goldmann tonometry in either eye 9. Any intraocular surgical procedure within the past 6 months in either eye 10. Inability to attend all scheduled study visits 11. Pregnant or planning to become pregnant in the next 4 years

Treatments Being Tested

PROCEDURE

Low Energy SLT

SLT performed at low energy

PROCEDURE

Standard Energy SLT

SLT performed at standard energy

Locations (20)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

Harvard Eye Associates
Laguna Hills, California, United States
Doheny Eye Center UCLA
Pasadena, California, United States
University of California, Davis
Sacramento, California, United States
University of California, San Francisco
San Francisco, California, United States
Mile High Eye Institute
Sheridan, Colorado, United States
Clear Vue Laser Eye Center
Lakeworth, Florida, United States
Northwestern Medical Group
Chicago, Illinois, United States
Chicago Arbor Eye Institute
Orland Park, Illinois, United States
Illinois Eye Center
Peoria, Illinois, United States
Wilmer Eye Institute Johns Hopkins
Baltimore, Maryland, United States
Massachusetts Eye and Ear
Boston, Massachusetts, United States
Ophthalmic Consultants of Boston
Boston, Massachusetts, United States
Mark Latina, LLC
Reading, Massachusetts, United States
University of Michigan Kellogg Eye Center
Ann Arbor, Michigan, United States
Kresge Eye Institute Wayne State University
Detroit, Michigan, United States
New York Eye Surgery Associates
The Bronx, New York, United States
University Hospitals Eye Institute
Cleveland, Ohio, United States
Cleveland Clinic Cole Eye Institute
Cleveland, Ohio, United States
Devers Eye Institute
Portland, Oregon, United States
Eye Care Specialists
Kingston, Pennsylvania, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT04967989), the sponsor (University of Pittsburgh), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT04967989 clinical trial studying?

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. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT04967989?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT04967989?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

Source: ClinicalTrials.gov API v2 record for NCT04967989. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT04967989. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-05-08 · Data from ClinicalTrials.gov.