Glaucoma Open-AngleNCT07486323
Combined Non-Invasive Brain and Visual Stimulation for Vision Improvement
A study testing NIBS, VTS and NIBS+VTS in people with Glaucoma Open-Angle, run by The Hong Kong Polytechnic University at 1 site in Hong Kong.
Trial summary
Glaucoma is a complex disease that can result in progressive vision loss. It is the second leading cause of blindness, accounting for 23% of permanent blindness in Hong Kong. There are no treatments that restore vision lost to glaucoma. Read more about this study
- Who is it for?
- Ages 40 to 80 years
- Conditions the study is for
- Glaucoma Open-Angle
- What is being tested?
- NIBS, VTS and NIBS+VTS
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 56 participants
- Where
- 1 siteHong Kong
- Study dates
- 20 Apr 2026to 10 Jul 2027
- Phase
- Interventional
- 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 40 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age range from 18 to 80 years;
- Diagnosis of primary open angle or normal tension glaucoma with relative scotoma in both eyes;
- A relative scotoma defined as a Humphrey Field Analyser (HFA) threshold perimetry loss (mean deviation of -6dB) within the central 24 degree of the visual field for at least one eye;
- Best-corrected distance visual acuity of 6/12 or better (equivalent to 0.3 logMAR acuity or better to confirm that participant's central vision is preserved).
- Stable vision and visual field loss for at least 3 months;
- With a cognitive functional score of 22 or above in the Montreal Cognitive Assessment - Hong Kong version (HK-MoCA) (to confirm participant's intact cognitive function).
Who cannot join
- Ocular diseases other than glaucoma (e.g. age-related macular degeneration, diabetic retinopathy, moderate to severe cataract) or severe hearing impairment (to ensure that participant can hear the instructions clearly during assessments and training);
- Severe medical problems (e.g. stroke, Parkinson's disease) or self-reported neurological (e.g. brain surgery, brain tumor, peripheral neuropathy), or cognitive disorders (e.g. diagnosed dementia or cognitive impairment);
- Self-reported vestibular or cerebellar dysfunction, history of vertigo;
- Using any medications for any neurological conditions or psychiatric drugs (e.g. sedative, hypnotic) that might interfere motor control;
- Contraindications for non-invasive brain stimulation.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Hong Kong1 site
The Hong Kong Polytechnic University
Hong Kong
Allen Cheong, PhD, 852-27666108, allen.my.cheong@polyu.edu.hk
Marco Chan, BSc (Hons) in Optometry, 852-34002309, lhinchan@polyu.edu.hk
About this study
Official title: Evaluation of Combined Non-invasive Brain Stimulation (NIBS) and Visual Tetanic Stimulation (VTS) for Vision Enhancement: A Randomized, Single-blind, Cross-over Trial
Glaucoma is a complex disease that can result in progressive vision loss. It is the second leading cause of blindness, accounting for 23% of permanent blindness in Hong Kong. There are no treatments that restore vision lost to glaucoma. This study will examine the effect of transcranial direct current stimulation (NIBS) on improving quality of life, visual function and functional performance in patients with peripheral field loss due to glaucoma.
Read the detailed description
This study uses a prospective, single-masked, randomized, cross-over, placebo-controlled training RCT design.
The eligible participants will be randomly allocated into 4 groups:
(A) Transcranial direct current stimulation; (B) Visual Tetanic Stimulation; (C) Transcranial direct current stimulation+ Visual Tetanic Stimulation; (D) Sham. All participants will underwent all the 4 types of intervention with a 14 days washing out period between intervention types:
All participants will complete twenty-six study visits:
Visit 1: Eligibility assessment (refer to the recruitment criteria); Visit 2: Outcome measures (Pre-intervention/ baseline); Visit 3-7: 5 sessions intervention (1st intervention block); Visit 8: Post 1 outcome measures; Visit 9-13: 5 sessions intervention (2nd intervention block); Visit 14: Post 2 outcome measures; Visit 15-19: 5 sessions intervention (3rd intervention block); Visit 20: Post 3 outcome measures; Visit 21-25: 5 sessions intervention (4th intervention block); Visit 26: Post 4 outcome measures
Eight sessions of assessment will be conducted: (1) Baseline-1; (2) Post-1 (after 5-sessions training); (3) Baseline-2; (4) Post-2 (after 5-sessions training); (5) Baseline-3; (6) Post-3 (after 5-sessions training); (7) Baseline-4; and (8) Post-4 (after 5-sessions training).
- Conditions
- Glaucoma Open-Angle
- Being tested
- NIBS, VTS, NIBS+VTS, Sham
- Keywords
- tDCS, transcranial electrical stimulation, visual tetanic stimulation, alpha frequency stimulation
- Medical subject headings
- Glaucoma, Open-Angle
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NIBSOther
Around 1 hour
VTSOther
Around 1 hour
NIBS+VTSOther
Around 1 hour
ShamOther
Around 1 hour
| Study group | Role | What they receive |
|---|---|---|
| Visual Tetanic Stimulation (VTS) | Experimental | Participant will receive 5 training sessions with VTS: about 1 hour per session Receives: Other: VTS |
| Transcranial direct current stimulation (NIBS) | Active comparator | Participant will receive 5 training sessions with NIBS: about 1 hour per session Receives: Other: NIBS |
| Transcranial direct current stimulation+ Visual Tetanic Stimulation (NIBS+VTS) | Experimental | Participant will receive 5 training sessions with NIBS+VTS: about 1 hour per session Receives: Other: NIBS+VTS |
| Sham | Placebo comparator | Participant will receive 5 training sessions with Sham: about 1 hour per session Receives: Other: Sham |
What is being measured
The primary outcome is the main question the study is designed to answer.
Visual field test
Visual field test is measured monocularly using the 24-2 Swedish interactive threshold algorithm (SITA) standard tests by Humphrey visual field analyzer (HFA, Carl Zeiss Meditec Inc., California). The mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI) are recorded, and the MD of the 24-2 visual field test will be used as the primary outcome of intervention effect.
Measured: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)
Electroencephalography (EEG)
Electrophysiological function is assessed using a 64-channel high-resolution electroencephalography (EEG) system. EEG outcome measures include spectral power in the delta, theta, alpha, beta, and gamma frequency bands, with particular focus on alpha-band activity, as well as functional connectivity measures derived from scalp EEG recordings, including coherence, phase-based connectivity, and related network indices.
Pattern-reversal visual evoked potentials (PR-VEP) are recorded during presentation of a high-contrast checkerboard stimulus to the central 20-degree visual field under monocular viewing conditions. Stimuli are presented at 0.5 Hz and 1.5 Hz with 40 reversals. PR-VEP outcome measures include N75 latency, P100 latency, N135 latency, and N75-P100 and/or P100-N135 amplitude.
Measured: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)
Optical Coherence Tomography (OCT)
Retinal nerve fiber layer is measured using spectral-domain Optical Coherence Tomography (OCT). Peripapillary retinal nerve fiber layer thickness is obtained from a circular scan centered on the optic nerve head. Ganglion cell thickness is measure using macular OCT imaging
Measured: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)
Optical Coherence Tomography Angiography (OCT-A)
Evaluation of retinal vascular function in glaucoma patients is measured. Detailed visualisation of microvasculature structure within the retina and optic nerve head is measured, change of ocular perfusion is shown.
Measured: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Mar 2026
- Study start20 Apr 2026 (estimated)
- Primary completion30 Jun 2027 (estimated)
- Study completion10 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Glaucoma Open-AngleStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 56 participants (estimated)
Sponsor and investigators
- Lead sponsor
- The Hong Kong Polytechnic University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Allen MY Cheong, The Hong Kong Polytechnic University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07486323
- Sponsor's protocol ID
- HSEARS20251208001
- Status last verified
- Mar 2026
- First submitted
- 10 Mar 2026
- Last updated
- 24 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data (IPD) underlying the results reported in this study will be shared via the Open Science Framework (OSF). These data will include participant-level demographic and clinical characteristics, baseline assessments, intervention-related variables, and primary and secondary outcome data necessary to reproduce the reported analyses. Supporting documents, including the study protocol, statistical analysis plan, data dictionary, and study materials, will also be made available on OSF.
Study at a glance
From the registry record, last updated by the sponsor on 24 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Combined Non-invasive Brain Stimulation (NIBS) and Visual Tetanic Stimulation (VTS) for Vision Enhancement: A Randomized, Single-blind, Cross-over Trial
- ClinicalTrials.gov ID
- NCT07486323
- Acronym / sponsor ID
- HSEARS20251208001
- Conditions
- Glaucoma Open-Angle
- Keywords
- tDCS, transcranial electrical stimulation, visual tetanic stimulation, alpha frequency stimulation
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 56 participants (estimated)
- Lead sponsor
- The Hong Kong Polytechnic UniversityUniversity, hospital or other
- Study start
- 20 Apr 2026 (estimated)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 10 Jul 2027 (estimated)
- First posted
- 20 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Glaucoma is a complex disease that can result in progressive vision loss. It is the second leading cause of blindness, accounting for 23% of permanent blindness in Hong Kong. There are no treatments that restore vision lost to glaucoma. This study will examine the effect of transcranial direct current stimulation (NIBS) on improving quality of life, visual function and functional performance in patients with peripheral field loss due to glaucoma.
Detailed description
This study uses a prospective, single-masked, randomized, cross-over, placebo-controlled training RCT design.
The eligible participants will be randomly allocated into 4 groups:
(A) Transcranial direct current stimulation; (B) Visual Tetanic Stimulation; (C) Transcranial direct current stimulation+ Visual Tetanic Stimulation; (D) Sham. All participants will underwent all the 4 types of intervention with a 14 days washing out period between intervention types:
All participants will complete twenty-six study visits:
Visit 1: Eligibility assessment (refer to the recruitment criteria); Visit 2: Outcome measures (Pre-intervention/ baseline); Visit 3-7: 5 sessions intervention (1st intervention block); Visit 8: Post 1 outcome measures; Visit 9-13: 5 sessions intervention (2nd intervention block); Visit 14: Post 2 outcome measures; Visit 15-19: 5 sessions intervention (3rd intervention block); Visit 20: Post 3 outcome measures; Visit 21-25: 5 sessions intervention (4th intervention block); Visit 26: Post 4 outcome measures
Eight sessions of assessment will be conducted: (1) Baseline-1; (2) Post-1 (after 5-sessions training); (3) Baseline-2; (4) Post-2 (after 5-sessions training); (5) Baseline-3; (6) Post-3 (after 5-sessions training); (7) Baseline-4; and (8) Post-4 (after 5-sessions training).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Visual Tetanic Stimulation (VTS) | Experimental | Other: VTSParticipant will receive 5 training sessions with VTS: about 1 hour per session |
| Transcranial direct current stimulation (NIBS) | Active comparator | Other: NIBSParticipant will receive 5 training sessions with NIBS: about 1 hour per session |
| Transcranial direct current stimulation+ Visual Tetanic Stimulation (NIBS+VTS) | Experimental | Other: NIBS+VTSParticipant will receive 5 training sessions with NIBS+VTS: about 1 hour per session |
| Sham | Placebo comparator | Other: ShamParticipant will receive 5 training sessions with Sham: about 1 hour per session |
Who may qualify
- Ages
- 40 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age range from 18 to 80 years;
- Diagnosis of primary open angle or normal tension glaucoma with relative scotoma in both eyes;
- A relative scotoma defined as a Humphrey Field Analyser (HFA) threshold perimetry loss (mean deviation of -6dB) within the central 24 degree of the visual field for at least one eye;
- Best-corrected distance visual acuity of 6/12 or better (equivalent to 0.3 logMAR acuity or better to confirm that participant's central vision is preserved).
- Stable vision and visual field loss for at least 3 months;
Key exclusion criteria (5 listed)
- Ocular diseases other than glaucoma (e.g. age-related macular degeneration, diabetic retinopathy, moderate to severe cataract) or severe hearing impairment (to ensure that participant can hear the instructions clearly during assessments and training);
- Severe medical problems (e.g. stroke, Parkinson's disease) or self-reported neurological (e.g. brain surgery, brain tumor, peripheral neuropathy), or cognitive disorders (e.g. diagnosed dementia or cognitive impairment);
- Self-reported vestibular or cerebellar dysfunction, history of vertigo;
- Using any medications for any neurological conditions or psychiatric drugs (e.g. sedative, hypnotic) that might interfere motor control;
- Contraindications for non-invasive brain stimulation.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| NIBSAround 1 hour | Other | Transcranial direct current stimulation (NIBS) |
| VTSAround 1 hour | Other | Visual Tetanic Stimulation (VTS) |
| NIBS+VTSAround 1 hour | Other | Transcranial direct current stimulation+ Visual Tetanic Stimulation (NIBS+VTS) |
| ShamAround 1 hour | Other | Sham |
Primary outcome
Visual field test
Time frame: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)
Visual field test is measured monocularly using the 24-2 Swedish interactive threshold algorithm (SITA) standard tests by Humphrey visual field analyzer (HFA, Carl Zeiss Meditec Inc., California). The mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI) are recorded, and the MD of the 24-2 visual field test will be used as the primary outcome of intervention effect.
Electroencephalography (EEG)
Time frame: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)
Electrophysiological function is assessed using a 64-channel high-resolution electroencephalography (EEG) system. EEG outcome measures include spectral power in the delta, theta, alpha, beta, and gamma frequency bands, with particular focus on alpha-band activity, as well as functional connectivity measures derived from scalp EEG recordings, including coherence, phase-based connectivity, and related network indices. Pattern-reversal visual evoked potentials (PR-VEP) are recorded during presentation of a high-contrast checkerboard stimulus to the central 20-degree visual field under monocular viewing conditions. Stimuli are presented at 0.5 Hz and 1.5 Hz with 40 reversals. PR-VEP outcome measures include N75 latency, P100 latency, N135 latency, and N75-P100 and/or P100-N135 amplitude.
Optical Coherence Tomography (OCT)
Time frame: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)
Retinal nerve fiber layer is measured using spectral-domain Optical Coherence Tomography (OCT). Peripapillary retinal nerve fiber layer thickness is obtained from a circular scan centered on the optic nerve head. Ganglion cell thickness is measure using macular OCT imaging
Optical Coherence Tomography Angiography (OCT-A)
Time frame: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)
Evaluation of retinal vascular function in glaucoma patients is measured. Detailed visualisation of microvasculature structure within the retina and optic nerve head is measured, change of ocular perfusion is shown.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Mar 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data (IPD) underlying the results reported in this study will be shared via the Open Science Framework (OSF). These data will include participant-level demographic and clinical characteristics, baseline assessments, intervention-related variables, and primary and secondary outcome data necessary to reproduce the reported analyses. Supporting documents, including the study protocol, statistical analysis plan, data dictionary, and study materials, will also be made available on OSF.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing NIBS, VTS and NIBS+VTS in people with Glaucoma Open-Angle, run by The Hong Kong Polytechnic University at 1 site in Hong Kong.
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 5 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: opening soon, as of the sponsor's last update on 24 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
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 Ming Yan Cheong, PhD (852-27666108, allen.my.cheong@polyu.edu.hk), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Visual field test (time frame: Baseline (before the first intervention session), and immediately before and after each intervention block (5 session of intervention)). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 24 Mar 2026.