Effectiveness of tDCS in Paediatric Amblyopia.

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.

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.

Conditions

• Amblyopia
• Amblyopia Strabismic
• Visual Acuity
• Stereoscopic Vision

Interventions

DEVICE

tDCS

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.

Sponsors & Collaborators

• Hospital Universitario Virgen de la Arrixaca

  collaborator OTHER

• Hospital Universitario Reina Sofia de Cordoba

  collaborator OTHER_GOV

• Hospital General Universitario Morales Meseguer

  collaborator OTHER

• Universidad de Murcia

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

4 Years

Max Age

14 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-06-01

Primary Completion

2026-06-30

Completion

2029-08-31