transcranial electrical stimulation (tES): 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.
Study 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.
Eligibility
Sex
ALL
Min age
18 Years
Max age
80 Years
Healthy volunteers
No
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.
Primary outcome measure(s)
High-resolution perimetry (HRP) — 0.5-1 hour 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.
Trial sites (1)
Facility
City
Region
Status
Allen MY Cheong
Hong Kong
China
Recruiting
More The Hong Kong Polytechnic University trials in China
This page summarises publicly available registry data for informational purposes — not medical advice. Eligibility is determined by each study team; patients should discuss participation with their clinician.
We use cookies to analyse site traffic and improve your experience. With your consent, we may also use cookies for advertising. You can change your choice at any time on our Cookie Policy page. See also our Privacy Policy.