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NCT05426044RecruitingPhase 2

Metformin as a Neuroprotective Therapy for Glaucoma

Metformin as a Neuroprotective Therapy for Glaucoma - A Randomized Controlled Trial

Source: ClinicalTrials.gov · Last updated 20 Nov 2025

Brief summary (registry, in English)

Glaucoma, a chronic degenerative disease of the optic nerve, is the leading cause of irreversible blindness worldwide. Although lowering the intraocular pressure (IOP) has been shown to be effective to slow optic nerve degeneration, a significant portion of glaucoma patients continue to develop progressive loss in vision despite adequate control of IOP. Development of neuroprotective therapy to prevent optic nerve degeneration by mechanisms other than IOP- lowering is critical to reduce the burden of glaucoma blindness. With 76 million glaucoma patients in 2020 worldwide, the need to investigate neuroprotection for glaucoma is pressing. While metformin is a widely adopted oral hypoglycemic medication for treatment of type 2 diabetes mellitus (DM), increasing evidence from clinical studies has shown that metformin can decrease the risk of many age-related diseases including neurodegenerative diseases. In a retrospective study of 150,016 patients with DM, those taking metformin at \>1500mg/day had a 25% reduced risk of development of open-angle glaucoma than those who took no metformin. Metformin has a high safety profile. The investigators aim to investigate whether metformin can be repurposed to a neuroprotective therapy for glaucoma patients in a randomized controlled trial. The investigators propose to conduct a 24-month, double-blind, placebo-controlled, parallel group, randomizing 125 primary open angle glaucoma patients who have progressive retinal nerve fiber layer (RNFL) and/or ganglion cell inner plexiform layer (GCIPL) thinning in at least one eye, as determined by optical coherence tomography Trend-based Progression Analysis (TPA) or Guided Progression Analysis (GPA), to receive metformin 1500mg/day or placebo. All patients will be followed up at 2-month intervals for IOP, RNFL thickness, and visual field (VF) measurements. The objectives are to compare (1) the rates of change of average RNFL thickness (primary outcome measure), and (2) the rates of change of VF mean deviation (MD) (secondary outcome measure) between treatment groups. The investigators hypothesize that patients treated with metformin have a slower rate of RNFL thinning, and a slower rate of VF MD decline compared with those treated with placebo at similar levels of IOP over the 24-month follow-up. The proposed study has the potential to mark a paradigm shift in the management of glaucoma patients by demonstrating that neuroprotection is attainable with metformin, which will alleviate the increasing burden of glaucoma blindness in China and other Asian countries where glaucoma patients with normal levels of IOP are prevalent. Furthermore, it will inform and impact the study design in future neuroprotection trials which can expedite the development of neuroprotective therapy for glaucoma.

Status (registry)
Recruiting
Phase (registry)
Phase 2
Study type
Interventional
Enrollment
125 (estimated)
First submitted
15 Jun 2022
Start date
1 Jun 2025
Primary completion date
31 Dec 2027
Lead sponsor
Christopher Kai Shun Leung
Diseases
Glaucoma
NCT number
NCT05426044

What you commit to

  • Study type: Interventional · Phase 2
  • Planned participants: 125
  • From 1 Jun 2025 to the primary completion date, 31 Dec 2027
  • 1 site in 1 country
  • Visits and tests: ask the trial team, the registry does not list them

Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.

Who cannot take part

Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.

Other illness

  • patients with DM, kidney or liver diseases
  • cognitive impairment (e.g. Alzheimer's disease)
  • diseases that may cause visual field loss or optic disc abnormalities other than glaucoma

Other

  • pathological myopia
  • inability to perform reliable visual field
  • suboptimal quality of OCT images.
    • Both eyes of a patient will be included in the analysis if both eyesare eligible for inclusion.

Who the study is looking for

  • age ≥18 years
  • best corrected VA ≥20/40
  • IOP ≤24mmHg at the screening and baseline visits
  • progressive RNFL and/or GCIPL thinning by TPA or GPA over the past 3 years in at least one eye.

Age in the registry: 18 years to - · Sex: All · Does not accept healthy volunteers

Full criteria on ClinicalTrials.gov

Sites (1)

Sites in registry order. Pick your city on the disease page to sort them by distance.

SiteCityCountrySite status
HKU Eye Centre
Coordinator of this site? Confirm its status
Wong Chuk HangHong Kong SAR ChinaRecruiting

This page is information, not medical advice. Discuss any trial with your doctor.