Optimal Non-invasive Brain Stimulation for Peripheral Vision

NCT04846140 | Recruiting

• 1 other identifier: R5047-19
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

Glaucoma is a complex disease that can result in progressive vision loss. There are no treatments that restore vision lost to glaucoma. However, recent studies have shown that vision can be improved by non-invasive brain (NIBS) stimulation and visual training. In this study, we aim to compare and find out the optimal non-invasive brain stimulation model (transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS)) for improving peripheral vision in glaucoma patients. The proposed treatment is the application of transcranial electrical stimulation (tES) onto the participant's head, with brain stimulation aimed at the Primary Visual Cortex toward the occipital pole. The investigators hypothesize that the tES will enable higher performance in the reading task and secondary measures due to an increase in the cortical excitability of the stimulated brain cells, and tRNS will generate the greatest acute improvement in peripheral vision than either a-tDCS, tACS, or sham stimulation.

Conditions

Glaucoma

Keywords

glaucoma; non-invasive brain stimulation; peripheral vision

Outcome Measures

Primary Outcomes (1)

• High-resolution perimetry (HRP)

  Visual field will be measured using high-resolution perimetry (HRP, HighTechVision, Sweden), which is a valid and reliable computer-based campimetric visual field assessment. Suprathreshold stimuli will be presented in random order at 474 different positions to one eye (i.e. the eye with larger field loss) while fixation is monitored. Detection accuracy and response times will be recorded to map the patient's area of residual vision (i.e. relative scotoma). Testing will occur pre- and immediately post- stimulation.

  0.5-1 hour

Secondary Outcomes (1)

• Multifocal visual evoked potential (mfVEP)

  0.5-1 hour

Study Arms (4)

tDCS group

EXPERIMENTAL

This group is defined as the participants who will receive tDCS at the first session. Participants in this group will receive 4 stimulation types (active a-tDCS, tACS, tRNS, and sham) in random order with at least a 48-hour separation between visits.

Device: transcranial electrical stimulation (tES)

tACS group

EXPERIMENTAL

This group is defined as the participants who will receive tACS at the first session. Participants in this group will receive 4 stimulation types (active a-tDCS, tACS, tRNS, and sham) in random order with at least a 48-hour separation between visits.

Device: transcranial electrical stimulation (tES)

tRNS group

EXPERIMENTAL

This group is defined as the participants who will receive tRNS at the first session. Participants in this group will receive 4 stimulation types (active a-tDCS, tACS, tRNS, and sham) in random order with at least a 48-hour separation between visits.

Device: transcranial electrical stimulation (tES)

sham group

EXPERIMENTAL

This group is defined as the participants who will receive sham stimulation at the first session. Participants in this group will receive 4 stimulation types (active a-tDCS, tACS, tRNS, and sham) in random order with at least a 48-hour separation between visits.

Device: transcranial electrical stimulation (tES)

Interventions

transcranial electrical stimulation (tES) DEVICE

Transcranial electrical stimulation (tES) is a form of neuromodulation that uses constant, low direct current delivered via the electrodes on the skull. Three types of tES will be applied in this study, include a-tDCS, tACS, and tRNS. Additionally, sham stimulation will be applied as a placebo-controlled intervention.

sham group; tACS group; tDCS group; tRNS group

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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 30° 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).

You may not qualify if:

• 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 with motor control;
• Contraindications for non-invasive brain stimulation.

Sponsors & Collaborators

• The Hong Kong Polytechnic University: lead
• Chinese University of Hong Kong: collaborator
• The University of Hong Kong: collaborator
• University of Waterloo: collaborator
• Hong Kong Metropolitan University: collaborator
• Otto-von-Guericke University Magdeburg: collaborator

Study Sites (1)

Allen MY Cheong

Hong Kong, China

RECRUITING

MeSH Terms

Conditions

Glaucoma

Interventions

Transcranial Direct Current Stimulation

Condition Hierarchy (Ancestors)

Ocular Hypertension; Eye Diseases

Intervention Hierarchy (Ancestors)

Electric Stimulation Therapy; Therapeutics; Convulsive Therapy; Psychiatric Somatic Therapies; Behavioral Disciplines and Activities; Electroshock; Psychological Techniques

Study Officials

• Allen Cheong, PhD

  The Hong Kong Polytechnic University

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Allen Cheong, PhD

CONTACT

852-27666108; allen.my.cheong@polyu.edu.hk

Ben Thompson, PhD

CONTACT

852-27666108; ben.thompson@uwaterloo.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate professor

Model Details: 3 sessions of 3 types of active brain stimulation and 1 session of placebo sham stimulation. Each participant will perform four sessions in a randomly-assigned order.

Study Record Dates

• First Submitted: April 12, 2021
• First Posted: April 15, 2021
• Study Start: November 1, 2021
• Primary Completion: July 1, 2025
• Study Completion: September 1, 2025
• Last Updated: October 29, 2024

Record last verified: 2024-10

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, ANALYTIC CODE
• Time Frame: IPD will be available no later than 6 months following publication and for 1 year.
• Access Criteria: IPD will be shared with investigators who provide a methodologically sound proposal.

Locations

CN (1)