# Clarifying the Optimal Application of SLT Therapy (COAST)

> **NIH NIH UG1** · WEST VIRGINIA UNIVERSITY · 2021 · $380,141

## Abstract

Open-angle glaucoma (OAG) is managed primarily with topical medical therapy, with laser and surgical
interventions reserved for those in whom medical therapy is ineffective, intolerable, or inappropriate. The
effectiveness of medical therapy is limited by patient adherence with therapy; inadequate adherence has been
extensively documented. Selective laser trabeculoplasty (SLT) has comparable efficacy to preferred first-line
prostaglandin analogues, is very safe, and obviates the need for daily medical therapy in most patients when
applied as primary therapy. A recent randomized trial demonstrated superior glaucoma outcomes (less
progression, fewer surgeries required) in newly diagnosed OAG patients receiving primary SLT vs. medical
therapy, providing the evidentiary basis for a paradigm shift that is already underway in which SLT supplants
medical therapy as the preferred first-line treatment for OAG. SLT is largely performed as first described by its
inventor; little exploration of dose-response has been undertaken. An intriguing data set from Italy (with
significant weaknesses and limitations) suggests that low energy SLT repeated annually is far more effective
than standard SLT repeated as needed when its effect wanes, in delaying or preventing the need for topical
medical therapy. This finding is consistent with the limited data exploring the dose-response relationship
between SLT and intraocular pressure (IOP) reduction. Further, it is biologically plausible that ongoing health
maintenance of trabecular meshwork (TM) function with proactive annual low energy SLT would better
preserve the TM's long-term health and function than a repeated cycle of SLT, progressive TM re-impairment
by the glaucoma process, loss of IOP control, and repeat SLT. Our proposal describes a multi-center clinical
trial to answer two key questions: 1) Is primary low energy SLT as effective as primary standard energy SLT in
newly diagnosed and treatment-naïve patients with mild-moderate OAH or high-risk ocular hypertension?; and
2) Does annual low energy repeat SLT more effectively delay or prevent the need for medical therapy
compared to standard SLT repeated as needed when its effect wanes and IOP rises? Participants will be
randomized to initial standard SLT or initial low energy SLT with the possibility of a single repeat SLT as
needed in the first year of the study. The first primary outcome will be 12-month survival where failure
represents the need for repeat SLT to achieve/maintain protocol-specified target IOP. At Month 12, all
participants who remain medication-free will be re-randomized to undergo repeat SLT either as needed when
IOP exceeds target IOP (at initially randomized energy) or to annual low energy SLT irrespective of IOP. The
second primary outcome will be 42-month medication-free survival in subjects who were medication-free at
Month 12. Our study seeks to clarify the optimal way to utilize SLT with the ultimate goal of maximizing long-
term SLT r...

## Key facts

- **NIH application ID:** 10328867
- **Project number:** 5UG1EY031654-02
- **Recipient organization:** WEST VIRGINIA UNIVERSITY
- **Principal Investigator:** Anthony Realini
- **Activity code:** UG1 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $380,141
- **Award type:** 5
- **Project period:** 2020-09-30 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10328867

## Citation

> US National Institutes of Health, RePORTER application 10328867, Clarifying the Optimal Application of SLT Therapy (COAST) (5UG1EY031654-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10328867. Licensed CC0.

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