Improving Peripheral Vision in Glaucoma with Brain Stimulation

Identify Optimal Non-invasive Brain Stimulation Paradigm for Improving Peripheral Vision

This study is testing different types of brain stimulation to see if they can improve peripheral vision in people with glaucoma.

Quick facts

• Phase: NA
• Study type: Interventional
• Enrollment: 40 (estimated)
• Ages: 18 Years to 80 Years
• Sex: All
• Sponsor: The Hong Kong Polytechnic University (other)
• Locations: 1 site (Hong Kong)
• Trial ID: NCT04846140 on ClinicalTrials.gov

What this trial studies

This study aims to identify the most effective non-invasive brain stimulation method for enhancing peripheral vision in patients with glaucoma. It will compare three types of transcranial electrical stimulation: transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS). Participants will undergo four stimulation sessions, including a sham stimulation, in a double-blind, placebo-controlled design. The primary outcome will be measured using high-resolution perimetry, while secondary outcomes will assess electrophysiological changes in the visual cortex.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 to 80 diagnosed with primary open-angle or normal-tension glaucoma and exhibiting relative scotoma in both eyes.

Not a fit: Patients with other ocular diseases or severe hearing impairments may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved peripheral vision for glaucoma patients, potentially enhancing their quality of life.

How similar studies have performed: Previous studies have shown promise in using non-invasive brain stimulation for visual enhancement, making this approach both innovative and supported by preliminary evidence.

Eligibility criteria

Inclusion Criteria:

1. Age range from 18 to 80 years;
2. Diagnosis of primary open angle or normal tension glaucoma with relative scotoma in both eyes;
3. 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;
4. 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);
5. Stable vision and visual field loss for at least 3 months;
6. 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).

Exclusion Criteria:

1. 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);
2. 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);
3. Self-reported vestibular or cerebellar dysfunction, history of vertigo;
4. Using any medications for any neurological conditions or psychiatric drugs (e.g. sedative, hypnotic) that might interfere with motor control;
5. Contraindications for non-invasive brain stimulation.

Where this trial is running

Hong Kong

• Allen MY Cheong — Hong Kong, China (RECRUITING)

Study contacts

• Principal investigator: Allen Cheong, PhD — The Hong Kong Polytechnic University
• Study coordinator: Allen Cheong, PhD

Conditions: Glaucoma, glaucoma, non-invasive brain stimulation, peripheral vision