Clinical Treatment of Transcranial Direct Current Stimulation in Older Adolescents With Amblyopia

January 6, 2025 updated by: Yatu Guo, Tianjin Eye Hospital

Efficacy of Transcranial Direct Current Stimulation in the Amblyopia Treatment of Older Adolescents: A Cohort Study

As a neurodevelopmental visual disorder, amblyopia, especially monocular form-deprivation amblyopia, can lead to severe visual developmental impairments. Due to reduced neural plasticity in the visual cortex after the critical period of visual development, older children and adults with amblyopia show poor responses to conventional treatments, lacking effective therapeutic options. Recent basic and clinical research has shown that transcranial direct current stimulation can effectively treat adult amblyopia by altering cortical excitability, enhancing synaptic plasticity, and affecting the excitatory/inhibitory balance in the cortex to reboot adult visual cortex plasticity. This proposed study aims to conduct a large-scale prospective randomized controlled trial to objectively assess the efficacy and safety of transcranial direct current stimulation in treating amblyopia in older adolescents and adults. By comparing changes in best-corrected visual acuity, visual evoked potentials(VEPs), contrast sensitivity, and functional connectivity between the visual cortex and other cortical areas using fMRI, the study seeks to provide robust clinical evidence, clarify the treatment effects of transcranial direct current stimulation in adult amblyopia, elucidate potential mechanisms of enhancing adult visual cortex plasticity with transcranial direct current stimulation, and potentially offer a safe and effective treatment modality for adult amblyopia.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

  1. A prospective cohort study designed to evaluate the effectiveness of transcranial direct current stimulation (tDCS) in improving visual outcomes in older adolescents with amblyopia. Anodal tDCS Group: Participants will receive anodal transcranial direct current stimulation (tDCS) with electrodes placed over the occipital cortex, chosen due to its critical role in processing visual information and its potential responsiveness to neuromodulation in amblyopia treatment. The stimulation will be set at 0.1 mA for 20 minutes per session, twice a week, over 6 months; Sham Stimulation Group: Participants will receive sham tDCS with electrodes similarly placed over the occipital cortex. The stimulation will be set at 0 mA for 20 minutes per session, twice a week, over 6 months.
  2. The impact of transcranial direct current stimulation on adult visual cortex plasticity and cortical functional assessment. Before and after transcranial direct current stimulation, resting-state and task-based functional magnetic resonance imaging (fMRI) are used to assess the functional activity between the visual cortex and other cortical regions. This evaluation aims to identify changes in adult visual cortex plasticity.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Tianjin
      • Tianjin, Tianjin, China, 300020
        • Recruiting
        • Tianjin Eye Hospital
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Children and their legal guardians have obtained consent in writing.
  • Participants aged 10-30, of any gender.
  • Participants must meet the diagnostic criteria for amblyopia: unilateral amblyopia with a difference of two lines or more in visual acuity between the eyes, or bilateral amblyopia with best-corrected visual acuity worse than 20/30 (or worse than 0.2 logMAR). The visual acuity charts to be used are LEA SYMBOLS® (Good-Lite Co., Elgin, IL) or HOTV visual acuity chart.

Exclusion Criteria:

  • Participants who may have eye diseases affecting vision or refractive errors (such as cataracts, crystalline lens damage, glaucoma, macular degeneration, corneal disorders, retinitis pigmentosa, retinal detachment, severe vitreous opacities, etc
  • History of eye trauma or intraocular surgery
  • Inability to cooperate with examinations
  • Presence of concomitant systemic diseases (such as epilepsy)
  • Participation in any other experimental treatment within the past 3 months
  • Other situations deemed unsuitable by the investigator.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Anodal tDCS Group
Participants will receive anodal transcranial direct current stimulation (tDCS) with electrodes placed over the occipital cortex, chosen due to its critical role in processing visual information and its potential responsiveness to neuromodulation in amblyopia treatment. The stimulation will be set at 0.1 mA for 20 minutes per session, twice a week, over 6 months
Procedure: tDCS Stimulation
Anode tDCS or sham stimulation for amblyopia of Adolescents
Device: Anodal tDCS
Anodal tDCS
Sham Comparator: Sham Stimulation Group
Participants will receive sham tDCS with electrodes similarly placed over the occipital cortex. The stimulation will be set at 0 mA for 20 minutes per session, twice a week, over 6 months
Device: Sham tDCS
Sham tDCS
Procedure: tDCS Stimulation
Anode tDCS or sham stimulation for amblyopia of Adolescents

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Improvement in Best Corrected Visual Acuity (BCVA)
Time Frame: 24 weeks
quantified by the number of lines gained on a standard visual acuity chart(HOTV chart). This measure will be assessed at baseline, 3 months, and 6 months post-intervention. A line gain is defined as the ability to correctly read an additional row of optotypes compared to baseline measurements. The improvement will be evaluated separately for each eye and averaged to assess overall treatment efficacy.
24 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in Visual Evoked Potential (VEP)
Time Frame: 24 weeks
changes in Visual Evoked Potential (VEP) metrics, specifically amplitude and latency, at 15 minutes and 1-degree visual angle stimulations. These measures will be used to assess the functional responsiveness of the visual pathways and cortical processing efficiency. Baseline, 3-month, and 6-month assessments will provide comparative data to evaluate the neurophysiological effects of the intervention.
24 weeks
Improvements in contrast sensitivity at different spatial frequencies
Time Frame: 24 weeks
Contrast sensitivity will be evaluated using a contrast sensitivity test with CSV-1000E(Vector vision, US), which measures the ability to detect differences in luminance across varying spatial frequencies (low 3 c/d, medium 6c/d、12 c/d, and high 18 c/d). Assessments will be conducted at baseline, 3 months, and 6 months post-intervention. The degree of improvement will be compared across groups to determine the impact of tDCS on visual function beyond acuity.
24 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Tianjin Eye Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 30, 2021

Primary Completion (Estimated)

May 30, 2026

Study Completion (Estimated)

December 30, 2026

Study Registration Dates

First Submitted

March 25, 2024

First Submitted That Met QC Criteria

January 6, 2025

First Posted (Actual)

March 25, 2025

Study Record Updates

Last Update Posted (Actual)

March 25, 2025

Last Update Submitted That Met QC Criteria

January 6, 2025

Last Verified

January 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • YK2023001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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