AmblyopiaNCT05016830
Bilateral Transcranial Direct Current Stimulation and Ocular Occlusion for Adults With Amblyopia
A study testing Bilateral transcranial direct current stimulation in people with Amblyopia, run by University of Chile at 1 site in Chile.
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. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Amblyopia
- What is being tested?
- Bilateral transcranial direct current stimulation
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 12 participants
- Where
- 1 siteChile
- Study dates
- 5 Nov 2019to 31 Jan 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Prior diagnosis of Amblyopia
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
Chile1 site
Faculty of Medicine of University of Chile
Santiago, Santiago Metropolitan, 8380453
About this study
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
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.
Read the detailed 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).
- Conditions
- Amblyopia
- Being tested
- Bilateral transcranial direct current stimulation
- Keywords
- Lazy eye syndrome, Transcranial direct current stimulation, Ocular occlusion, Amblyopia
- Medical subject headings
- Amblyopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Bilateral transcranial direct current stimulationDevice
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.
| Study group | Role | What they receive |
|---|---|---|
| Sham bilateral transcranial direct current stimulation | Sham comparator | Sham bilateral transcranial direct current stimulation consisted of 2 milliamperes (mA) of current from the anodal electrode in the amblyopic primary visual cortex to the cathodal electrode located in the fellow primary visual cortex, but the stimulation was turned off after 30 seconds. On Sham Stimulation onset, the participant's fellow eye was occluded and the participant performed a reading task for 20 minutes. Receives: Device: Bilateral transcranial direct current stimulation |
| Bilateral transcranial direct current stimulation | Experimental | Bilateral transcranial direct current stimulation consisted of 2 mA of current from the anodal electrode in the amblyopic primary visual cortex to the cathodal electrode located in the fellow primary visual cortex and the stimulation was on for 20 minutes. On stimulation onset, the participant's fellow eye was occluded and the participant performed a reading task for 20 minutes. Receives: Device: Bilateral transcranial direct current stimulation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Visual Acuity
Clarity or Sharpness in vision, measured in LogMar
Measured: 1-2 hours
Visual Sensitivity
The ability to perceive differences between an object and its background, measured in percentage of contrast sensitivity.
Measured: 1-2 hours
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.
Measured: 1-2 hours
Visual evoked potentials
The electroencephalographic response from the primary visual cortex to a stimuli. Measured in millivolts (mV).
Measured: 1-2 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Aug 2021
- Study start5 Nov 2019
- Primary completion31 Jan 2020
- Study completion31 Jan 2020
Why it stopped: Lock-down in the city of Santiago due to Covid-19 pandemia. Most faculty premises were closed for research purposes and mobility in the city was restricted.
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
- A randomized, controlled pilot trial, that consists in two groups: a control group that receives sham stimulation and ocular occlusion, and a second group that receives bilateral transcranial direct current stimulation and ocular occlusion.
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Outcomes assessor
- Enrolment
- 12 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Chile
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Romulo Antonio Fuentes Flores, University of Chile
- Investigators
- Romulo A Fuentes Flores, PhD, Principal investigator, University of Chile
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05016830
- Sponsor's protocol ID
- CECI-HCUCH Nº44-2019
- Status last verified
- Aug 2021
- First submitted
- 13 Aug 2021
- Last updated
- 23 Aug 2021
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Aug 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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
- ClinicalTrials.gov ID
- NCT05016830
- Acronym / sponsor ID
- CECI-HCUCH Nº44-2019
- Conditions
- Amblyopia
- Keywords
- Lazy eye syndrome, Transcranial direct current stimulation, Ocular occlusion, Amblyopia
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Lock-down in the city of Santiago due to Covid-19 pandemia. Most faculty premises were closed for research purposes and mobility in the city was restricted.
- Enrolment
- 12 participants (actual)
- Lead sponsor
- University of ChileUniversity, hospital or other
- Study start
- 5 Nov 2019 (actual)
- Primary completion
- 31 Jan 2020 (actual)
- Study completion
- 31 Jan 2020 (actual)
- First posted
- 23 Aug 2021 (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.
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.
Detailed 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).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, outcomes assessor)
- Number of arms
- 2
- Model description
- A randomized, controlled pilot trial, that consists in two groups: a control group that receives sham stimulation and ocular occlusion, and a second group that receives bilateral transcranial direct current stimulation and ocular occlusion.
| Arm | Type | Receives |
|---|---|---|
| Sham bilateral transcranial direct current stimulation | Sham comparator | Device: Bilateral transcranial direct current stimulationSham bilateral transcranial direct current stimulation consisted of 2 milliamperes (mA) of current from the anodal electrode in the amblyopic primary visual cortex to the cathodal electrode located in the fellow primary visual cortex, but the stimulation was turned off after 30 seconds. On Sham Stimulation onset, the participant's fellow eye was occluded and the participant performed a reading task for 20 minutes. |
| Bilateral transcranial direct current stimulation | Experimental | Device: Bilateral transcranial direct current stimulationBilateral transcranial direct current stimulation consisted of 2 mA of current from the anodal electrode in the amblyopic primary visual cortex to the cathodal electrode located in the fellow primary visual cortex and the stimulation was on for 20 minutes. On stimulation onset, the participant's fellow eye was occluded and the participant performed a reading task for 20 minutes. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- Prior diagnosis of Amblyopia
Key exclusion criteria (7 listed)
- Ophthalmologic disease other than amblyopia
- Chronic pharmacological therapy
- Implanted medical device
- Neurologic disease or surgery history
- History of an adverse reaction to tDCS
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 |
|---|---|---|
| Bilateral transcranial direct current stimulationA 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. | Device | Bilateral transcranial direct current stimulation, Sham bilateral transcranial direct current stimulation |
Primary outcome
Visual Acuity
Time frame: 1-2 hours
Clarity or Sharpness in vision, measured in LogMar
Visual Sensitivity
Time frame: 1-2 hours
The ability to perceive differences between an object and its background, measured in percentage of contrast sensitivity.
Stereopsis
Time frame: 1-2 hours
the perception of depth produced by the reception in the brain of visual stimuli from both eyes in combination. Measured in degrees of arc.
Visual evoked potentials
Time frame: 1-2 hours
The electroencephalographic response from the primary visual cortex to a stimuli. Measured in millivolts (mV).
Results and safety
The study was stopped early (reason given: Lock-down in the city of Santiago due to Covid-19 pandemia. Most faculty premises were closed for research purposes and mobility in the city was restricted.). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Aug 2021.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
Romulo A Fuentes Flores, PhD principal investigator
University of Chile
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Bilateral transcranial direct current stimulation in people with Amblyopia, run by University of Chile at 1 site in Chile.
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 1 inclusion and 7 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: stopped early, as of the sponsor's last update on 23 Aug 2021. 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 Chile. 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?
The study was stopped early (reason given: Lock-down in the city of Santiago due to Covid-19 pandemia. Most faculty premises were closed for research purposes and mobility in the city was restricted.). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Visual Acuity (time frame: 1-2 hours). 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 23 Aug 2021.