AmblyopiatDCSNCT07547670
Effectiveness of tDCS in Paediatric Amblyopia.
A study testing tDCS in people with Amblyopia and Amblyopia Strabismic, run by Universidad de Murcia at 1 site in Spain.
Trial summary
The goal of this randomized, double-blind clinical trial is to determine whether transcranial direct current stimulation (tDCS) can effectively and safely improve vision in children aged 4-14 years with strabismic or anisometropic amblyopia that has not responded to conventional patching therapy. Read more about this study
- Who is it for?
- Ages 4 to 14 years
- Conditions the study is for
- Amblyopia, Amblyopia Strabismic, Visual Acuity
- What is being tested?
- tDCS
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 100 participants
- Where
- 1 siteSpain
- Study dates
- 2 May 2026to 31 Aug 2029
- 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 4 to 14 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- Children aged 4-14 years.
- Strabismic amblyopia resistant to patching (PEDIG criteria).
- Anisometropic amblyopia resistant to patching (PEDIG criteria).
Who cannot join
- Ocular pathology.
- Nystagmus.
- Mental disability.
- Cognitive delay.
- Neurological problems incompatible with treatment.
- Pacemakers.
Show all 11Show fewer
- Intracranial electrodes.
- Implanted defibrillators.
- Cranial pathologies.
- Cranial lesions.
- Withdrawal will occur upon adverse events, protocol deviation, refusal, or loss to follow-up.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Spain1 site, 1 recruiting
- Recruiting
University of Murcia
Murcia, 30100
Francisco Javier Valiente Soriano, Dr, 0034 868 88 4503, fjvaliente@um.es
About this study
The goal of this randomized, double-blind clinical trial is to determine whether transcranial direct current stimulation (tDCS) can effectively and safely improve vision in children aged 4-14 years with strabismic or anisometropic amblyopia that has not responded to conventional patching therapy.
The main questions it aims to answer are:
Read more
Does tDCS produce significant and sustained improvements in visual acuity, contrast sensitivity, and stereopsis in children with amblyopia?
Is tDCS a safe, well-tolerated, and faster alternative or complementary treatment compared with standard occlusion therapy?
Does tDCS induce functional and structural changes in the visual cortex associated with increased neuroplasticity, including modulation of GABAergic activity?
If there is a comparison group:
Researchers will compare active tDCS with sham (placebo) stimulation to see if active treatment leads to greater visual recovery and cortical changes than placebo.
Participants will:
Receive several sessions of active or sham tDCS using low-intensity electrical stimulation applied to visual brain areas.
Undergo standard visual assessments, including visual acuity, contrast sensitivity, and stereopsis.
Complete neurophysiological and neuroimaging evaluations (EEG, pattern visual evoked potentials, and functional MRI).
Provide biochemical measures related to GABA levels.
This study aims to validate tDCS as a non-invasive, child-friendly, and effective therapy that may overcome the limitations of patching and support its inclusion in paediatric clinical practice.
Read the detailed description
Amblyopia is a neurodevelopmental visual disorder characterised by reduced visual performance despite optimal optical correction and the absence of ocular pathology. It affects up to 2-4% of children and is the leading cause of visual impairment in this population. Conventional treatment involves optical correction and patching of the contralateral (non-amblyopic) eye, which usually produces limited improvement, low therapeutic compliance and frequent relapses, highlighting the need for new approaches based on neuroplasticity.
Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that can modify cortical excitability by regulating GABAergic inhibition in the primary visual cortex (V1). It has been safely used in children with attention deficit disorder, schizophrenia, epilepsy or cerebral palsy.
Preliminary data from our group show that after three sessions of tDCS on paediatric strabismic amblyopia, there are significant and sustained improvements in visual acuity, contrast sensitivity, and stereopsis at 3 months.
This project proposes a randomised, double-blind clinical trial to evaluate the efficacy, safety and optimal dosage regimen of tDCS in children aged 4 to 14 years with strabismic or anisometropic amblyopia classified as non-responsive to occlusion therapy, according to the criteria established by the Pediatric Eye Disease Investigation Group (PEDIG). Objective biomarkers will be included using electroencephalogram, visual evoked potentials (pattern) and functional magnetic resonance imaging to explore cortical functional and structural changes, together with biochemical assessment of GABA levels.
The expected outcome is to validate tDCS as an effective, rapid, and safe alternative or complementary therapy for amblyopia. Demonstrating sustained visual and cortical improvements would support its inclusion in paediatric clinical protocols and promote translational neuro-ophthalmological rehabilitation
- Conditions
- Amblyopia, Amblyopia Strabismic, Visual Acuity, Stereoscopic Vision
- Being tested
- tDCS
- Keywords
- tDCS, Ambyopia
- Medical subject headings
- Amblyopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
tDCSDevice
The direct current is gradually increased over 34 seconds until it reaches 2 mA, remains constant for 15 minutes, and then is gradually reduced to zero using NIC2® v2.1.2.0 software (Neuroelectrics®, Barcelona, Spain). The stimulating current is applied using two rubber electrodes housed in circular sponge pockets (8 cm² each) soaked in saline solution. The electrodes are placed at Oz (active/stimulating electrode, located in the visual cortex) and Cz (reference electrode). This includes a total of 3 sessions of 15 minutes and 34 seconds separated by 48 hours.
| Study group | Role | What they receive |
|---|---|---|
| Group tDCS | Experimental | Children aged 4 to 14 with amblyopia treated at one of the collaborating hospitals and centers, with visual acuity in the amblyopic eye between 20/32 and 20/200. They will undergo tests of visual acuity, stereoscopic visual acuity, fixation, and contrast sensitivity. The direct current will be gradually increased over 34 seconds to 2 mA, held constant for 15 minutes, and then gradually reduced to zero using NIC2® v2.1.2.0 software (Neuroelectrics®, Barcelona, Spain). The stimulating current is applied using two rubber electrodes housed in circular sponge pockets (8 cm² each) soaked in saline solution. The electrodes are placed at Oz (active/stimulating electrode, located in the visual cortex) and Cz (reference electrode). Receives: Device: tDCS |
| Group Sham | Sham comparator | The sham group is equipped with the same electrostimulation helmet, but the intensity protocol is set to 0 at all times. The same measurements are taken and exactly the same procedure is followed as with the experimental group. Receives: Device: tDCS |
What is being measured
The primary outcome is the main question the study is designed to answer.
Visual Acuity
Visual acuity measurements were performed by the same examiner, using a calibrated optotype at a distance of six meters, before starting treatment, after each session, one month after treatment, and three months after treatment.
Measured: 3 months
Stereoscopic visual acuity
Stereoscopic visual acuity was measured using TNO test (with the butterfly plate corresponding to 1300" and the circular plate to 1200"), the subject places the test 40 cm away and must identify calibrated figures.
Measured: 3 months
Contrast sensitivity
Contrast sensitivity was measured using CSV-1000 test (3, 6, 12, and 18 cycles per degree). The patient must identify scratched circles whose frequency is decreasing.
Measured: 3 months
Eye Fixation
Eye fixation was evaluated using the Topcon Macular Integrity Assessment (MAIA) microperimeter (Topcon corporation, Tokyo, Japan), which delineates two distinct regions using 1° (P1) and 2° (P2) circles.
Measured: 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Apr 2026
- Study start2 May 2026
- Primary completion1 Jun 2026
- Study completion31 Aug 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AmblyopiaStudies 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
- Parallel groups
- Model description
- During months 1 to 6, preparatory activities will include obtaining ethical approvals, installing equipment, and selecting participants. From months 6 to 24, the main intervention phase will take place, comprising tDCS stimulation, optometric and microperimetric assessments, and clinical follow-up (study 1), together with neurophysiological recordings (VEP and EEG) under the same experimental conditions (study 2). This period will also include a six-month booster stimulation phase to assess the persistence of treatment effects. At the same time, data curation and preliminary analyses of studies 1 and 2 will be carried out. Starting in month 24, study 3 will focus on neurofunctional and neurochemical assessments using functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (MRS). Between months 30 and 36, data from the three studies will be integrated, followed by final statistical analyses, interpretation, and preparation of scientific reports and manuscripts.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universidad de Murcia
- Sponsor type
- University, hospital or other
- Collaborators
- Hospital Universitario Virgen de la Arrixaca, Hospital Universitario Reina Sofia de Cordoba, Hospital General Universitario Morales Meseguer
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07547670
- Sponsor's protocol ID
- T-TDCS-PJY
- Acronym
- tDCS
- Status last verified
- Jan 2026
- First submitted
- 16 Apr 2026
- Last updated
- 28 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 28 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effectiveness of tDCS in Paediatric Amblyopia.
- ClinicalTrials.gov ID
- NCT07547670
- Acronym / sponsor ID
- tDCS / T-TDCS-PJY
- Conditions
- Amblyopia, Amblyopia Strabismic, Visual Acuity, Stereoscopic Vision
- Keywords
- tDCS, Ambyopia
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- Universidad de MurciaUniversity, hospital or other
- Collaborators
- Hospital Universitario Virgen de la Arrixaca, Hospital Universitario Reina Sofia de Cordoba, Hospital General Universitario Morales Meseguer
- Study start
- 2 May 2026 (actual)
- Primary completion
- 1 Jun 2026 (actual)
- Study completion
- 31 Aug 2029 (estimated)
- First posted
- 23 Apr 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.
The goal of this randomized, double-blind clinical trial is to determine whether transcranial direct current stimulation (tDCS) can effectively and safely improve vision in children aged 4-14 years with strabismic or anisometropic amblyopia that has not responded to conventional patching therapy.
The main questions it aims to answer are:
Does tDCS produce significant and sustained improvements in visual acuity, contrast sensitivity, and stereopsis in children with amblyopia?
Is tDCS a safe, well-tolerated, and faster alternative or complementary treatment compared with standard occlusion therapy?
Does tDCS induce functional and structural changes in the visual cortex associated with increased neuroplasticity, including modulation of GABAergic activity?
If there is a comparison group:
Researchers will compare active tDCS with sham (placebo) stimulation to see if active treatment leads to greater visual recovery and cortical changes than placebo.
Participants will:
Receive several sessions of active or sham tDCS using low-intensity electrical stimulation applied to visual brain areas.
Undergo standard visual assessments, including visual acuity, contrast sensitivity, and stereopsis.
Complete neurophysiological and neuroimaging evaluations (EEG, pattern visual evoked potentials, and functional MRI).
Provide biochemical measures related to GABA levels.
This study aims to validate tDCS as a non-invasive, child-friendly, and effective therapy that may overcome the limitations of patching and support its inclusion in paediatric clinical practice.
Detailed description
Amblyopia is a neurodevelopmental visual disorder characterised by reduced visual performance despite optimal optical correction and the absence of ocular pathology. It affects up to 2-4% of children and is the leading cause of visual impairment in this population. Conventional treatment involves optical correction and patching of the contralateral (non-amblyopic) eye, which usually produces limited improvement, low therapeutic compliance and frequent relapses, highlighting the need for new approaches based on neuroplasticity.
Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulation technique that can modify cortical excitability by regulating GABAergic inhibition in the primary visual cortex (V1). It has been safely used in children with attention deficit disorder, schizophrenia, epilepsy or cerebral palsy.
Preliminary data from our group show that after three sessions of tDCS on paediatric strabismic amblyopia, there are significant and sustained improvements in visual acuity, contrast sensitivity, and stereopsis at 3 months.
This project proposes a randomised, double-blind clinical trial to evaluate the efficacy, safety and optimal dosage regimen of tDCS in children aged 4 to 14 years with strabismic or anisometropic amblyopia classified as non-responsive to occlusion therapy, according to the criteria established by the Pediatric Eye Disease Investigation Group (PEDIG). Objective biomarkers will be included using electroencephalogram, visual evoked potentials (pattern) and functional magnetic resonance imaging to explore cortical functional and structural changes, together with biochemical assessment of GABA levels.
The expected outcome is to validate tDCS as an effective, rapid, and safe alternative or complementary therapy for amblyopia. Demonstrating sustained visual and cortical improvements would support its inclusion in paediatric clinical protocols and promote translational neuro-ophthalmological rehabilitation
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
- Model description
- During months 1 to 6, preparatory activities will include obtaining ethical approvals, installing equipment, and selecting participants. From months 6 to 24, the main intervention phase will take place, comprising tDCS stimulation, optometric and microperimetric assessments, and clinical follow-up (study 1), together with neurophysiological recordings (VEP and EEG) under the same experimental conditions (study 2). This period will also include a six-month booster stimulation phase to assess the persistence of treatment effects. At the same time, data curation and preliminary analyses of studies 1 and 2 will be carried out. Starting in month 24, study 3 will focus on neurofunctional and neurochemical assessments using functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (MRS). Between months 30 and 36, data from the three studies will be integrated, followed by final statistical analyses, interpretation, and preparation of scientific reports and manuscripts.
| Arm | Type | Receives |
|---|---|---|
| Group tDCS | Experimental | Device: tDCSChildren aged 4 to 14 with amblyopia treated at one of the collaborating hospitals and centers, with visual acuity in the amblyopic eye between 20/32 and 20/200. They will undergo tests of visual acuity, stereoscopic visual acuity, fixation, and contrast sensitivity. The direct current will be gradually increased over 34 seconds to 2 mA, held constant for 15 minutes, and then gradually reduced to zero using NIC2® v2.1.2.0 software (Neuroelectrics®, Barcelona, Spain). The stimulating current is applied using two rubber electrodes housed in circular sponge pockets (8 cm² each) soaked in saline solution. The electrodes are placed at Oz (active/stimulating electrode, located in the visual cortex) and Cz (reference electrode). |
| Group Sham | Sham comparator | Device: tDCSThe sham group is equipped with the same electrostimulation helmet, but the intensity protocol is set to 0 at all times. The same measurements are taken and exactly the same procedure is followed as with the experimental group. |
Who may qualify
- Ages
- 4 to 14 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- Children aged 4-14 years.
- Strabismic amblyopia resistant to patching (PEDIG criteria).
- Anisometropic amblyopia resistant to patching (PEDIG criteria).
Key exclusion criteria (11 listed)
- Ocular pathology.
- Nystagmus.
- Mental disability.
- Cognitive delay.
- Neurological problems incompatible with treatment.
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 |
|---|---|---|
| tDCSThe direct current is gradually increased over 34 seconds until it reaches 2 mA, remains constant for 15 minutes, and then is gradually reduced to zero using NIC2® v2.1.2.0 software (Neuroelectrics®, Barcelona, Spain). The stimulating current is applied using two rubber electrodes housed in circular sponge pockets (8 cm² each) soaked in saline solution. The electrodes are placed at Oz (active/stimulating electrode, located in the visual cortex) and Cz (reference electrode). This includes a total of 3 sessions of 15 minutes and 34 seconds separated by 48 hours. | Device | Group Sham, Group tDCS |
Primary outcome
Visual Acuity
Time frame: 3 months
Visual acuity measurements were performed by the same examiner, using a calibrated optotype at a distance of six meters, before starting treatment, after each session, one month after treatment, and three months after treatment.
Stereoscopic visual acuity
Time frame: 3 months
Stereoscopic visual acuity was measured using TNO test (with the butterfly plate corresponding to 1300" and the circular plate to 1200"), the subject places the test 40 cm away and must identify calibrated figures.
Contrast sensitivity
Time frame: 3 months
Contrast sensitivity was measured using CSV-1000 test (3, 6, 12, and 18 cycles per degree). The patient must identify scratched circles whose frequency is decreasing.
Eye Fixation
Time frame: 3 months
Eye fixation was evaluated using the Topcon Macular Integrity Assessment (MAIA) microperimeter (Topcon corporation, Tokyo, Japan), which delineates two distinct regions using 1° (P1) and 2° (P2) circles.
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 28 Jul 2026.
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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 tDCS in people with Amblyopia and Amblyopia Strabismic, run by Universidad de Murcia at 1 site in Spain.
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 3 inclusion and 11 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: looking for participants now, as of the sponsor's last update on 28 Jul 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 Spain. 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 Dr. Francisco Javier Valiente Soriano, Optics and Optometry (+34 670 25 58 48, fjvaliente@um.es), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Visual Acuity (time frame: 3 months). 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 28 Jul 2026.