AmblyopiaNIMANCT07846397
Non-invasive Induction of Metaplasticity for Amblyopia
A study testing Flicker in people with Amblyopia and Amblyopia Unilateral, run by Boston Children's Hospital.
Trial summary
The goal of this clinical trial is to determine the efficacy of flicker therapy as an adjunct therapy to treat amblyopia beyond the critical period in adolescents and adults aged 14-40 years who have amblyopia of ≥3 lines of interocular best-corrected (with glasses) visual acuity difference. Read more about this study
- Who is it for?
- Ages 14 to 40 years
- Conditions the study is for
- Amblyopia, Amblyopia Unilateral, Amblyopia, Anisometropic
- What is being tested?
- Flicker
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 10 participants
- Where
- No sites listed yet
- Study dates
- Nov 2026to Mar 2027
- 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 14 to 40 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- Age ≥14 and ≤40 years
- Amblyopia associated with strabismus and/or anisometropia
- Criteria for strabismus: must meet at least one of the following: heterotropia at distance and/or near with or without spectacle correction, history of strabismus surgery, documented history of strabismus that is no longer present and felt by the investigator could have caused the amblyopia
- Criteria for anisometropia: must meet at least one of the following:
- ≥ 0.50 D difference in spherical equivalent between eyes
- ≥ 1.50 D difference in astigmatism in any meridian between the eyes
Show all 22Show fewer
- Visual acuity measured in each eye within 7 days prior to enrollment using ETDRS protocol on a study certified visual acuity tester as follows:
- Amblyopic eye visual acuity of 20/40 - 20/400
- Fellow eye visual acuity of ≥ 20/25.
- Spectacle correction for measurement of enrollment visual acuity must meet the following criteria and be based on a cycloplegic refraction < 6 months old:
- Requirement for spectacle correction:
- Spherical equivalent must be within 0.50 D of fully correcting anisometropia
- Hyperopia ≥ 3.00 D must be corrected
- Hyperopia may not be under-corrected by >1.50 D spherical equivalent and must be symmetrically reduced in each eye
- Cylinder power must be within 0.50 D of fully correcting the astigmatism
- Cylinder axis must be within 6 degrees of the axis when the cylinder power is ≥ 1.00 D
- Myopia of the amblyopic eye >0.50 D spherical equivalent must be corrected
- Myopia may not be under-corrected by >0.25 D or overcorrected by > 0.50D
- Spectacles meeting the above criteria must be worn until visual acuity in amblyopic eye has not improved ≥ 1 line (5 letters) by the same testing method during 2 consecutive visual acuity measurements at least 4 weeks apart (i.e. minimum of 12 weeks spectacle correction)
- Dilated eye examination within 6 months prior to enrollment
- Subject must be available for at least 4 months of follow-up, have access to a phone, and be willing to be contacted
- By investigator judgment, the subject is likely to comply with prescribed treatment (i.e. no prior history of poor compliance) and complete all follow up visits
Who cannot join
- Myopia > -6.00 D spherical equivalent
- Presence of associated findings that could cause reduced visual acuity
- Nystagmus does not exclude the subject if the above visual acuity criteria are met
- Treatment with topical atropine within the past 12 weeks
- Previous intraocular or refractive surgery
- Strabismus surgery planned within 16 weeks
Show all 14Show fewer
- Current vision therapy or orthoptics
- History of seizures
- Known past or present susceptibility to seizures at the discretion of the investigator
- Known past or present psychological problems
- Known contraindications or inability to use of a head-mounted device (over one's glasses) and/or exposure to flickering light
- Current use of medication for the treatment of seizures, bipolar disorder, or migraine
- Use of any medication with neuromodulatory effects, including
- Medications that reduce seizure thresholds
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
Chaya Manjeshwar, BS contact
About this study
Official title: Non-invasive Induction of Metaplasticity to Treat Amblyopia in Adolescent and Adult Patients
The goal of this clinical trial is to determine the efficacy of flicker therapy as an adjunct therapy to treat amblyopia beyond the critical period in adolescents and adults aged 14-40 years who have amblyopia of ≥3 lines of interocular best-corrected (with glasses) visual acuity difference.
The main questions it aims to answer are:
- Does flicker therapy enable clinically meaningful and durable visual recovery from amblyopia?
- Do flicker therapy-treated patients show a change in amblyopic eye visual acuity (lines)? Participants will undergo daily flicker therapy for 1 hour per day.
Read the detailed description
The study is a prospective, single arm, open-label, dose-escalation, pilot trial to evaluate the efficacy of daily flicker exposure for the treatment of residual amblyopia in patients 14-40 years of age. Amblyopia, the leading cause of monocular visual impairment in children, is responsive to early interventions such as patching and pharmacologic penalization; however, many patients remain with residual visual deficits despite treatment. Current approaches are limited by age-dependent declines in cortical plasticity after closure of the visual system's "critical period."
Flicker therapy is a new concept, most notably being investigated in the realm of Alzheimer's Disease (AD) to assess cognitive improvements and as a treatment for insomnia. Recent preclinical testing in rodents has shown that metaplasticity can be non-invasively "tuned" by light flickering at different frequencies to encourage different forms of synaptic plasticity in the cerebral cortex, including modifications that enable recovery of function, offering an unprecedented opportunity for amblyopia care. Translational work has further shown that flicker therapy can reopen critical periods in humans, as evidenced by the slowdown of cognitive decline in adult AD subjects, and improved sleep quality in insomniac children. Together, these data provide strong proof-of-concept support for repurposing flicker therapy as a treatment for amblyopia by reactivating plasticity mechanisms rather than targeting neuromodulatory pathways alone.
In this study, 10 subjects with residual amblyopia (best-corrected amblyopic eye visual acuity 20/40-20/400, stable over ≥8 weeks) will receive the VistaSync Visual Stimulation System VTX100, a device which provides the flicker therapy, to use for one hour each day. After the initial phase, subjects will be evaluated for any visual acuity changes. Dose escalation up to 2 hours/day will be permitted at interim visits if insufficient visual improvement is observed without adverse effects.
The primary endpoint is change in visual acuity in the amblyopic eye after 8 weeks of treatment. Secondary endpoints include the proportion of patients achieving resolution of amblyopia, change in stereoacuity, durability of treatment response after cross-over, visual acuity in the fellow eye, and prospective evaluation of the flicker therapy safety profile in this population.
Subjects will be monitored closely through a structured schedule of phone calls and in-person visits over 12 weeks. Safety assessments include symptom surveys. Standardized visual acuity and stereoacuity testing will be performed at each visit. Compliance will be tracked using device logs and investigator assessments.
Potential risks include known adverse effects of flicker therapy, ranging from common but generally mild headaches and neurological symptoms to rare severe outcomes such as seizures. Subjects will be carefully screened for contraindications, including epilepsy. The Prinicipal Investigator and an independent medical examiner will oversee adverse event reporting and trial safety.
This trial is intended as a proof-of-concept study to establish feasibility, safety, and preliminary efficacy of flicker therapy for residual amblyopia. Results will inform the design of a larger multicenter randomized trial and provide essential data on effect size, tolerability, and durability of response. If successful, this work could represent a paradigm shift in amblyopia treatment by introducing a non-invasive, plasticity-enhancing approach with the potential for durable recovery of vision in adolescents and adults who currently have limited therapeutic options.
- Being tested
- Flicker
- Keywords
- Amblyopia, Flicker therapy, Pediatric, Lazy eye, Visual acuity, Visual impairment, critical period, adults, adolescents, ophthalmology
- Medical subject headings
- Amblyopia, Vision Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FlickerDevice
The device is intended for investigational use in children (14 years old and up) and adults with amblyopia to evaluate the once daily use (up to 2 hours) over the study period of 8 weeks.
Key characteristics of the system include:
- Non-implantable
- Externally applied
- No electrical stimulation delivered to the body
- No invasive components or procedures
- No life-sustaining or life-supporting function
The device consists of a handheld, battery-powered controller, an eyeset, and a power charger. The device is intended for daily use at home.
| Study group | Role | What they receive |
|---|---|---|
| Arm 1 - Flicker Therapy | Experimental | Participants will be required to use the VistaSync Visual Stimulation System VTX100 for 1 hours daily throughout the 8-week study period. At the mid-point 4-week study visit, the dose may be escalated to 2 hours daily, as investigator sees fit. This regimen aims to improve visual acuity in the amblyopic eye by encouraging its use. Compliance with the this protocol will be monitored, and participants will be provided with instructions and support to ensure proper device usage and adherence to the treatment. Receives: Device: Flicker |
What is being measured
The primary outcome is the main question the study is designed to answer.
Amblyopic Eye Best-Corrected Visual Acuity (BCVA)
Change in visual acuity of the amblyopic eye after 8 weeks of flicker treatment
Measured: From enrollment to the end of treatment at 8 weeks
Secondary outcomes (5)
Proportion of patients with resolved amblyopia
Proportion of participants achieving resolution of amblyopia, defined as visual acuity in the amblyopic eye of 20/25 or better, following 8 weeks of treatment.
Measured: 8 weeks
Durability of amblyopic eye visual acuity response
The visual acuity in the amblyopic eye will be compared between the 8 week visit (when flicker therapy is discontinued) to the 16 week visit. This difference reflects the maintenance of visual acuity and will be analyzed and interpreted in the context of change at an individual level in response to flicker therapy between weeks 0 and 8. The proportion of subjects maintaining a ≥ 10 letters (2 lines) improvement in the amblyopic eye visual acuity will be calculated and a 95% confidence interval on overall change will be computed.
Measured: From end of treatment at 8 weeks to end of follow-up at 16 weeks
Change in stereoacuity
Change in log arcsec in stereoacuity assessed with the Randot Preschool Stereoacuity Test. The change in log arcseconds will be compared between groups. Aggregated results will inform how overall stereoacuity has changed, and the difference from baseline will be compared across treatment groups and timepoints.
Measured: 8 weeks and 16 weeks
Quality of life measures using the Amblyopia & Strabismis Questionnaire
This measure assesses the quality of life deficits across four domains: functional vision, bothered by eyes/vision, social, and frustration/worry. It uses a 3-point frequency scale and Rasch-calibrated domain scores (0-100).
Measured: Change from baseline at 8 weeks and 16 weeks
Tolerability and Safety of Flicker Therapy
This measure evaluates the tolerability and safety of flicker therapy, assessing the proportion of patients reporting mild, moderate, and severe adverse events, and comparing the proportion of participants requiring dose tapering or de-escalation.
Measured: Assessed throughout the study duration at 1,2, 4, 6, 8, 9, 10, 12, 14 and 16 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2026
- Study startNov 2026 (estimated)
- Primary completionJan 2027 (estimated)
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (53)Papers the sponsor has linked to this study.
- Other trials for AmblyopiaStudies of the same condition, open and under way.
- More trials run by Boston Children's HospitalThe sponsor's other registered studies.
- 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
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 10 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Boston Children's Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- Massachusetts Institute of Technology
- Responsible party
- Principal investigator, Eric Gaier, Boston Children's Hospital
- Investigators
- Eric D Gaier, MD PhD, Principal investigator, Boston Children's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07846397
- Sponsor's protocol ID
- IRB-P00051936
- Acronym
- NIMA
- Status last verified
- Sep 2026
- First submitted
- 23 Sep 2026
- Last updated
- 29 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: We plan to share individual participant data (IPD) with qualified researchers to promote transparency and further research. Data will be de-identified to ensure privacy and confidentiality. Researchers must submit a formal request outlining their study purpose and intended use of the data. Requests will be reviewed by our study team for ethical and scientific alignment. Data will be shared through a secure online repository, accessible to approved researchers. Shared data will include demographic information, clinical outcomes, visual acuity measurements, stereoacuity results, quality of life assessments, and adverse event reports. Researchers must agree to use the data solely for approved purposes and not share it with third parties without consent. Researchers are encouraged to publish their findings in peer-reviewed journals and acknowledge the original study and investigators.
Publications
Birch EE, Morale SE, Jost RM, De La Cruz A, Kelly KR, Wang YZ, Bex PJ. Assessing Suppression in Amblyopic Children With a Dichoptic Eye Chart. Invest Ophthalmol Vis Sci. 2016 Oct 1;57(13):5649-5654. doi: 10.1167/iovs.16-19986.
PubMed 27784068Wu C, Gaier ED, Nihalani BR, Whitecross S, Hensch TK, Hunter DG. Durable recovery from amblyopia with donepezil. Sci Rep. 2023 Jun 22;13(1):10161. doi: 10.1038/s41598-023-34891-5.
PubMed 37349338Kelly KR, Jost RM, Wang YZ, Dao L, Beauchamp CL, Leffler JN, Birch EE. Improved Binocular Outcomes Following Binocular Treatment for Childhood Amblyopia. Invest Ophthalmol Vis Sci. 2018 Mar 1;59(3):1221-1228. doi: 10.1167/iovs.17-23235.
PubMed 29625442Sharif MH, Talebnejad MR, Rastegar K, Khalili MR, Nowroozzadeh MH. Oral fluoxetine in the management of amblyopic patients aged between 10 and 40 years old: a randomized clinical trial. Eye (Lond). 2019 Jul;33(7):1060-1067. doi: 10.1038/s41433-019-0360-z. Epub 2019 Feb 19.
PubMed 30783259Reilly-Andujar F, Cramer TLM, Wang EY, Chang NW, Chang YW, Heynen AJ, Bear MF. Tuning metaplasticity in the adult visual cortex using flickering light. bioRxiv [Preprint]. 2026 Feb 18:2026.02.16.706197. doi: 10.64898/2026.02.16.706197.
PubMed 41757096Kirkwood A, Rioult MC, Bear MF. Experience-dependent modification of synaptic plasticity in visual cortex. Nature. 1996 Jun 6;381(6582):526-8. doi: 10.1038/381526a0.
PubMed 8632826Muller-Dahlhaus F, Ziemann U. Metaplasticity in human cortex. Neuroscientist. 2015 Apr;21(2):185-202. doi: 10.1177/1073858414526645. Epub 2014 Mar 11.
PubMed 24620008Zhou X, He Y, Xu T, Wu Z, Guo W, Xu X, Liu Y, Zhang Y, Shang H, Huang L, Yao Z, Li Z, Su L, Li Z, Feng T, Zhang S, Monteiro O, Cunha RA, Huang ZL, Zhang K, Li Y, Cai X, Qu J, Chen JF. 40 Hz light flickering promotes sleep through cortical adenosine signaling. Cell Res. 2024 Mar;34(3):214-231. doi: 10.1038/s41422-023-00920-1. Epub 2024 Feb 8.
PubMed 38332199Schiel R, Vilser W, Kovar F, Kramer G, Braun A, Stein G. Retinal vessel response to flicker light in children and adolescents with type 1 diabetes mellitus and overweight or obesity. Diabetes Res Clin Pract. 2009 Mar;83(3):358-64. doi: 10.1016/j.diabres.2008.11.001. Epub 2008 Dec 18.
PubMed 19100645Chan D, de Weck G, Jackson BL, Suk HJ, Milman NP, Kitchener E, Avalos VSF, Quay MJ, Aoki K, Ruiz E, Becker A, Zheng M, Philips R, Firenze R, Geigenmuller U, Hammerschlag B, Arnold S, Kivisakk P, Brickhouse M, Touroutoglou A, Brown EN, Boyden ES, Dickerson BC, Klerman EB, Tsai LH. Gamma sensory stimulation in mild Alzheimer's dementia: An open-label extension study. Alzheimers Dement. 2025 Oct;21(10):e70792. doi: 10.1002/alz.70792.
PubMed 41137616Chan D, Suk HJ, Jackson BL, Milman NP, Stark D, Klerman EB, Kitchener E, Fernandez Avalos VS, de Weck G, Banerjee A, Beach SD, Blanchard J, Stearns C, Boes AD, Uitermarkt B, Gander P, Howard M 3rd, Sternberg EJ, Nieto-Castanon A, Anteraper S, Whitfield-Gabrieli S, Brown EN, Boyden ES, Dickerson BC, Tsai LH. Gamma frequency sensory stimulation in mild probable Alzheimer's dementia patients: Results of feasibility and pilot studies. PLoS One. 2022 Dec 1;17(12):e0278412. doi: 10.1371/journal.pone.0278412. eCollection 2022.
PubMed 36454969Echavarri-Leet MP, Resnick HH, Bowen DA, Goss D, Bear MF, Gaier ED. Spontaneous recovery from amblyopia following fellow eye vision loss: a systematic review and narrative synthesis. J AAPOS. 2024 Aug;28(4):103971. doi: 10.1016/j.jaapos.2024.103971. Epub 2024 Jul 14.
PubMed 39009183Amanat M, Togha M, Agah E, Ramezani M, Tavasoli AR, Azizi Malamiri R, Fashandaky F, Heidari M, Salehi M, Eshaghi H, Ashrafi MR. Cinnarizine and sodium valproate as the preventive agents of pediatric migraine: A randomized double-blind placebo-controlled trial. Cephalalgia. 2020 Jun;40(7):665-674. doi: 10.1177/0333102419888485. Epub 2019 Nov 10.
PubMed 31707814Hiilesmaa VK, Bardy AH, Granstrom ML, Teramo KA. Valproic acid during pregnancy. Lancet. 1980 Apr 19;1(8173):883. doi: 10.1016/s0140-6736(80)91387-2. No abstract available.
PubMed 6103246Nau H, Hauck RS, Ehlers K. Valproic acid-induced neural tube defects in mouse and human: aspects of chirality, alternative drug development, pharmacokinetics and possible mechanisms. Pharmacol Toxicol. 1991 Nov;69(5):310-21. doi: 10.1111/j.1600-0773.1991.tb01303.x.
PubMed 1803343
Study at a glance
From the registry record, last updated by the sponsor on 29 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Non-invasive Induction of Metaplasticity to Treat Amblyopia in Adolescent and Adult Patients
- ClinicalTrials.gov ID
- NCT07846397
- Acronym / sponsor ID
- NIMA / IRB-P00051936
- Keywords
- Amblyopia, Flicker therapy, Pediatric, Lazy eye, Visual acuity, Visual impairment, critical period, adults
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 10 participants (estimated)
- Lead sponsor
- Boston Children's HospitalUniversity, hospital or other
- Collaborators
- Massachusetts Institute of Technology
- Study start
- Nov 2026 (estimated)
- Primary completion
- Jan 2027 (estimated)
- Study completion
- Mar 2027 (estimated)
- First posted
- 29 Sep 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 clinical trial is to determine the efficacy of flicker therapy as an adjunct therapy to treat amblyopia beyond the critical period in adolescents and adults aged 14-40 years who have amblyopia of ≥3 lines of interocular best-corrected (with glasses) visual acuity difference.
The main questions it aims to answer are:
- Does flicker therapy enable clinically meaningful and durable visual recovery from amblyopia?
- Do flicker therapy-treated patients show a change in amblyopic eye visual acuity (lines)? Participants will undergo daily flicker therapy for 1 hour per day.
Detailed description
The study is a prospective, single arm, open-label, dose-escalation, pilot trial to evaluate the efficacy of daily flicker exposure for the treatment of residual amblyopia in patients 14-40 years of age. Amblyopia, the leading cause of monocular visual impairment in children, is responsive to early interventions such as patching and pharmacologic penalization; however, many patients remain with residual visual deficits despite treatment. Current approaches are limited by age-dependent declines in cortical plasticity after closure of the visual system's "critical period."
Flicker therapy is a new concept, most notably being investigated in the realm of Alzheimer's Disease (AD) to assess cognitive improvements and as a treatment for insomnia. Recent preclinical testing in rodents has shown that metaplasticity can be non-invasively "tuned" by light flickering at different frequencies to encourage different forms of synaptic plasticity in the cerebral cortex, including modifications that enable recovery of function, offering an unprecedented opportunity for amblyopia care. Translational work has further shown that flicker therapy can reopen critical periods in humans, as evidenced by the slowdown of cognitive decline in adult AD subjects, and improved sleep quality in insomniac children. Together, these data provide strong proof-of-concept support for repurposing flicker therapy as a treatment for amblyopia by reactivating plasticity mechanisms rather than targeting neuromodulatory pathways alone.
In this study, 10 subjects with residual amblyopia (best-corrected amblyopic eye visual acuity 20/40-20/400, stable over ≥8 weeks) will receive the VistaSync Visual Stimulation System VTX100, a device which provides the flicker therapy, to use for one hour each day. After the initial phase, subjects will be evaluated for any visual acuity changes. Dose escalation up to 2 hours/day will be permitted at interim visits if insufficient visual improvement is observed without adverse effects.
The primary endpoint is change in visual acuity in the amblyopic eye after 8 weeks of treatment. Secondary endpoints include the proportion of patients achieving resolution of amblyopia, change in stereoacuity, durability of treatment response after cross-over, visual acuity in the fellow eye, and prospective evaluation of the flicker therapy safety profile in this population.
Subjects will be monitored closely through a structured schedule of phone calls and in-person visits over 12 weeks. Safety assessments include symptom surveys. Standardized visual acuity and stereoacuity testing will be performed at each visit. Compliance will be tracked using device logs and investigator assessments.
Potential risks include known adverse effects of flicker therapy, ranging from common but generally mild headaches and neurological symptoms to rare severe outcomes such as seizures. Subjects will be carefully screened for contraindications, including epilepsy. The Prinicipal Investigator and an independent medical examiner will oversee adverse event reporting and trial safety.
This trial is intended as a proof-of-concept study to establish feasibility, safety, and preliminary efficacy of flicker therapy for residual amblyopia. Results will inform the design of a larger multicenter randomized trial and provide essential data on effect size, tolerability, and durability of response. If successful, this work could represent a paradigm shift in amblyopia treatment by introducing a non-invasive, plasticity-enhancing approach with the potential for durable recovery of vision in adolescents and adults who currently have limited therapeutic options.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Arm 1 - Flicker Therapy | Experimental | Device: FlickerParticipants will be required to use the VistaSync Visual Stimulation System VTX100 for 1 hours daily throughout the 8-week study period. At the mid-point 4-week study visit, the dose may be escalated to 2 hours daily, as investigator sees fit. This regimen aims to improve visual acuity in the amblyopic eye by encouraging its use. Compliance with the this protocol will be monitored, and participants will be provided with instructions and support to ensure proper device usage and adherence to the treatment. |
Who may qualify
- Ages
- 14 to 40 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (22 listed)
- Age ≥14 and ≤40 years
- Amblyopia associated with strabismus and/or anisometropia
- Criteria for strabismus: must meet at least one of the following: heterotropia at distance and/or near with or without spectacle correction, history of strabismus surgery, documented history of strabismus that is no longer present and felt by the investigator could have caused the amblyopia
- Criteria for anisometropia: must meet at least one of the following:
- ≥ 0.50 D difference in spherical equivalent between eyes
Key exclusion criteria (14 listed)
- Myopia > -6.00 D spherical equivalent
- Presence of associated findings that could cause reduced visual acuity
- Nystagmus does not exclude the subject if the above visual acuity criteria are met
- Treatment with topical atropine within the past 12 weeks
- Previous intraocular or refractive surgery
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 |
|---|---|---|
| FlickerThe device is intended for investigational use in children (14 years old and up) and adults with amblyopia to evaluate the once daily use (up to 2 hours) over the study period of 8 weeks. Key characteristics of the system include: * Non-implantable * Externally applied * No electrical stimulation delivered to the body * No invasive components or procedures * No life-sustaining or life-supporting function The device consists of a handheld, battery-powered controller, an eyeset, and a power charger. The device is intended for daily use at home. | Device | Arm 1 - Flicker Therapy |
Primary outcome
Amblyopic Eye Best-Corrected Visual Acuity (BCVA)
Time frame: From enrollment to the end of treatment at 8 weeks
Change in visual acuity of the amblyopic eye after 8 weeks of flicker treatment
5 secondary outcomes
Proportion of patients with resolved amblyopia
Time frame: 8 weeks
Durability of amblyopic eye visual acuity response
Time frame: From end of treatment at 8 weeks to end of follow-up at 16 weeks
Change in stereoacuity
Time frame: 8 weeks and 16 weeks
Quality of life measures using the Amblyopia & Strabismis Questionnaire
Time frame: Change from baseline at 8 weeks and 16 weeks
Tolerability and Safety of Flicker Therapy
Time frame: Assessed throughout the study duration at 1,2, 4, 6, 8, 9, 10, 12, 14 and 16 weeks
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 29 Sep 2026.
- Background: PubMed 27784068Birch EE, Morale SE, Jost RM, De La Cruz A, Kelly KR, Wang YZ, Bex PJ. Assessing Suppression in Amblyopic Children With a Dichoptic Eye Chart. Invest Ophthalmol Vis Sci. 2016 Oct 1;57(13):5649-5654. doi: 10.1167/iovs.16-19986.
- Background: PubMed 37349338Wu C, Gaier ED, Nihalani BR, Whitecross S, Hensch TK, Hunter DG. Durable recovery from amblyopia with donepezil. Sci Rep. 2023 Jun 22;13(1):10161. doi: 10.1038/s41598-023-34891-5.
- Background: PubMed 29625442Kelly KR, Jost RM, Wang YZ, Dao L, Beauchamp CL, Leffler JN, Birch EE. Improved Binocular Outcomes Following Binocular Treatment for Childhood Amblyopia. Invest Ophthalmol Vis Sci. 2018 Mar 1;59(3):1221-1228. doi: 10.1167/iovs.17-23235.
- Background: PubMed 30783259Sharif MH, Talebnejad MR, Rastegar K, Khalili MR, Nowroozzadeh MH. Oral fluoxetine in the management of amblyopic patients aged between 10 and 40 years old: a randomized clinical trial. Eye (Lond). 2019 Jul;33(7):1060-1067. doi: 10.1038/s41433-019-0360-z. Epub 2019 Feb 19.
- Background: PubMed 41757096Reilly-Andujar F, Cramer TLM, Wang EY, Chang NW, Chang YW, Heynen AJ, Bear MF. Tuning metaplasticity in the adult visual cortex using flickering light. bioRxiv [Preprint]. 2026 Feb 18:2026.02.16.706197. doi: 10.64898/2026.02.16.706197.
- Background: PubMed 8632826Kirkwood A, Rioult MC, Bear MF. Experience-dependent modification of synaptic plasticity in visual cortex. Nature. 1996 Jun 6;381(6582):526-8. doi: 10.1038/381526a0.
- Background: PubMed 24620008Muller-Dahlhaus F, Ziemann U. Metaplasticity in human cortex. Neuroscientist. 2015 Apr;21(2):185-202. doi: 10.1177/1073858414526645. Epub 2014 Mar 11.
- Background: PubMed 38332199Zhou X, He Y, Xu T, Wu Z, Guo W, Xu X, Liu Y, Zhang Y, Shang H, Huang L, Yao Z, Li Z, Su L, Li Z, Feng T, Zhang S, Monteiro O, Cunha RA, Huang ZL, Zhang K, Li Y, Cai X, Qu J, Chen JF. 40 Hz light flickering promotes sleep through cortical adenosine signaling. Cell Res. 2024 Mar;34(3):214-231. doi: 10.1038/s41422-023-00920-1. Epub 2024 Feb 8.
- Background: PubMed 19100645Schiel R, Vilser W, Kovar F, Kramer G, Braun A, Stein G. Retinal vessel response to flicker light in children and adolescents with type 1 diabetes mellitus and overweight or obesity. Diabetes Res Clin Pract. 2009 Mar;83(3):358-64. doi: 10.1016/j.diabres.2008.11.001. Epub 2008 Dec 18.
- Background: PubMed 41137616Chan D, de Weck G, Jackson BL, Suk HJ, Milman NP, Kitchener E, Avalos VSF, Quay MJ, Aoki K, Ruiz E, Becker A, Zheng M, Philips R, Firenze R, Geigenmuller U, Hammerschlag B, Arnold S, Kivisakk P, Brickhouse M, Touroutoglou A, Brown EN, Boyden ES, Dickerson BC, Klerman EB, Tsai LH. Gamma sensory stimulation in mild Alzheimer's dementia: An open-label extension study. Alzheimers Dement. 2025 Oct;21(10):e70792. doi: 10.1002/alz.70792.
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- Background: PubMed 39009183Echavarri-Leet MP, Resnick HH, Bowen DA, Goss D, Bear MF, Gaier ED. Spontaneous recovery from amblyopia following fellow eye vision loss: a systematic review and narrative synthesis. J AAPOS. 2024 Aug;28(4):103971. doi: 10.1016/j.jaapos.2024.103971. Epub 2024 Jul 14.
- Individual participant dataSharing planned: Yes. We plan to share individual participant data (IPD) with qualified researchers to promote transparency and further research. Data will be de-identified to ensure privacy and confidentiality. Researchers must submit a formal request outlining their study purpose and intended use of the data. Requests will be reviewed by our study team for ethical and scientific alignment. Data will be shared through a secure online repository, accessible to approved researchers. Shared data will include demographic information, clinical outcomes, visual acuity measurements, stereoacuity results, quality of life assessments, and adverse event reports. Researchers must agree to use the data solely for approved purposes and not share it with third parties without consent. Researchers are encouraged to publish their findings in peer-reviewed journals and acknowledge the original study and investigators.
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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.
Chaya Manjeshwar, BS contact
Eric D Gaier, MD PhD principal investigator
Boston Children's Hospital
Questions about this trial
What is this clinical trial studying?
A study testing Flicker in people with Amblyopia and Amblyopia Unilateral, run by Boston Children's Hospital.
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 22 inclusion and 14 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: opening soon, as of the sponsor's last update on 29 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. 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. Eric D Gaier, MD PhD (617-355-6401, Eric.Gaier@childrens.harvard.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Amblyopic Eye Best-Corrected Visual Acuity (BCVA) (time frame: From enrollment to the end of treatment at 8 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07846397, which also lists 53 linked publications.
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 29 Sep 2026.