Bilateral Transcranial Direct Current Stimulation and Ocular Occlusion for Adults With Amblyopia

Amblyopia Clinical Trial

Official title:

Effect of the Combination of tDCS and Visual Occlusion Therapy on Visual Acuity, Contrast Vision and Depth Vision, in Adult Patients With Amblyopia

Clinical Trial Details — Status: Terminated

Administrative data

• NCT number: NCT05016830
• Other study ID #: CECI-HCUCH Nº44-2019
• Status: Terminated
• Phase: N/A
• Start date: November 5, 2019
• Est. completion date: January 31, 2020

Study information

• Verified date: August 2021
• Source: University of Chile
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

A prospective interventional study is expected to be conducted, to test a possible new treatment for amblyopia (lazy eye syndrome). Bilateral transcranial direct current stimulation (tDCS) is a type of noninvasive brain stimulation, which may help in visual function recovery of adult patients with amblyopia. This pilot study will test the feasibility of said therapy, along with the short term effects of bilateral tDCS in visual function.

Description:

Theoretical Framework: Ocular occlusion treatment has been used classically and with excellent results for the treatment of amblyopia in those under 14 years of age, since in this period it has been seen that there is greater neuroplasticity, leaving little to do in the period of lower neuroplasticity, in young and adult patients with later diagnoses. Transcranial Direct Current Stimulation therapy is an emergent technique used in neurological diseases to increase neuroplasticity, by changing the resting potential of neurons. Our hypothesis is that the combination of tDCS and visual occlusion therapy is capable of increasing visual acuity, contrast sensitivity, and depth perception, in young people over 18 years of age.

Methodology: The application of a double-blind, randomized clinical trial is proposed to evaluate the application of 2 different therapies: Occlusion with bilateral tDCS, and Occlusion with tDCS sham (sham). The study subjects will be randomly assigned to a group, and one session of stimulation will be performed. Data will be analyzed using Student's t test, or Mann-Whitney test, according to the normal or non-normal distribution of the sample, respectively. Also, the change over time of the variables will be measured using the Conditional Change Model.

Expected Results: The investigators expect that visual acuity, contrast vision, and dichoptic vision in the Occlusion therapy group with bilateral tDCS will be significantly higher than the Occlusion therapy group with tDCS sham (sham).

Recruitment information / eligibility

• Status: Terminated
• Enrollment: 12
• Est. completion date: January 31, 2020
• Est. primary completion date: January 31, 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• Prior diagnosis of Amblyopia

Exclusion Criteria:

• Ophthalmologic disease other than amblyopia

• Chronic pharmacological therapy

• Implanted medical device

• Neurologic disease or surgery history

• History of an adverse reaction to tDCS

• Pregnancy

• Not able to give informed consent

Related Conditions & MeSH terms

• Amblyopia

Intervention

Device:
• Bilateral transcranial direct current stimulation
A direct current is applied with two electrodes (cathode and anode) in specific parts of the skull. In this case the anode was over the occipital area to target the amblyopic cortex, while the cathode was over the contralateral side, targeting the fellow cortex.

Locations

Country	Name	City	State
Chile	Faculty of Medicine of University of Chile	Santiago	Region Metropolitana

Sponsors (1)

Lead Sponsor	Collaborator
University of Chile

Country where clinical trial is conducted

Chile, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Visual Acuity	Clarity or Sharpness in vision, measured in LogMar	1-2 hours
Primary	Visual Sensitivity	The ability to perceive differences between an object and its background, measured in percentage of contrast sensitivity.	1-2 hours
Primary	Stereopsis	the perception of depth produced by the reception in the brain of visual stimuli from both eyes in combination. Measured in degrees of arc.	1-2 hours
Primary	Visual evoked potentials	The electroencephalographic response from the primary visual cortex to a stimuli. Measured in millivolts (mV).	1-2 hours