Noninvasive Brain Stimulation in Adult Amblyopia

Multi-day Effect of Noninvasive Brain Stimulation in Adults With Amblyopia

The goal of this randomized controlled trial is to investigate the effectiveness of non-invasive brain stimulation in treating adults with amblyopia. The main questions it aims to answer are:

1. What are the effects of non-invasive brain stimulation on neuronal plasticity in the visual cortex of adults with amblyopia, and does it produce lasting changes?
2. Do cumulative sessions of non-invasive brain stimulation influence neural plasticity and higher-order visual functions in adults with amblyopia?

The investigators hypothesize that non-invasive brain stimulation will show a positive cumulative effect after five (5) consecutive days of stimulation on visual perception and function in adults with amblyopia.

Participants will be randomized into one of two treatment groups:

1. High-frequency transcranial random noise stimulation (hf-tRNS).
2. Sham stimulation.

Researchers will compare baseline measurements of crowded visual acuity, contrast sensitivity, stereoacuity, phosphene thresholds, global motion perception, form pattern recognition and pattern-reversal visual evoked potentials (VEPs) to post-treatment measurements for each group.

Inclusion Criteria:

• Adults between 18 and 55 years of age
• Formal diagnosis of amblyopia in one or both eyes of any etiology

Exclusion Criteria:

• History of optic nerve disease, including glaucoma and optic neuritis
• History of neurological conditions, including demyelinating disease or stroke
• Presence of metal or electronic implants in or on the body, including pacemakers
• Taking medications that can affect normal neurological function, including antipsychotics, antiepileptics, and opioids