AmblyopiaNCT05393739
Effect of Transcranial Magnetic Stimulation on Visual Functions of Adult Amblyopia: a Preliminary Study
A study testing Theta burst transcranial magnetic stimulation (TBS) procedure in people with Amblyopia, run by National Taiwan University Hospital at 1 site in Taiwan.
Trial summary
Amblyopia, with a prevalence rates of 3% in adult population, is a common cause of vision impairment. It is characterized by impaired vision in one or both eyes because of disruption of normal visual stimuli and underdevelopment of the visual cortex, leads to lifelong visual deficits affecting both monocular and… Read more about this study
- Who is it for?
- Ages 20 to 50 years
- Conditions the study is for
- Amblyopia
- What is being tested?
- Theta burst transcranial magnetic stimulation (TBS) procedure
- Type of treatment
- Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteTaiwan
- Study dates
- 5 Jan 2023to 31 Dec 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 20 to 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Adult amblyopia participants, aged 20-50 years old.
- Based on inclusion criteria, there was a minimum of 2 lines difference in BCVA between the 2 eyes.
- An amblyogenic factor and history of amblyopia treatment was recorded
Who cannot join
- Unstable vital sign
- History of brain injury and/or head trauma
- Neurological and psychiatric disease
- Seizures or family history of seizure
- Pregnancy
- Uncontrolled migraine or the presence of metallic implants or shunt in the head or torso
Show all 11Show fewer
- Wide region of ischemic cicatrix, multiple sclerosis, taking tricycle antidepressants,
- Analgesics or any drugs may decrease the threshold for inducing seizure
- Experienced sleep disorders during the rTMS treatment
- Severe alcoholism or taking seizure drugs
- Severe heart diseases or uncontrollable migraine caused by high intracranial pressure
Trial locations and contacts
1 site in 1 country.
About this study
Amblyopia, with a prevalence rates of 3% in adult population, is a common cause of vision impairment. It is characterized by impaired vision in one or both eyes because of disruption of normal visual stimuli and underdevelopment of the visual cortex, leads to lifelong visual deficits affecting both monocular and binocular visual function. Common causes of amblyopia include refraction error, anisometropia, strabismus and visual deprivation arising from ptosis or congenital cataract. Our previous studies had shed light on the relationship between abnormal early visual experience, and development of later amblyopia and possible neural developmental disorders. Functional recovery is difficult when neuroplasticity slows down at the end of the critical period. To date, there is no established effective treatment for adult amblyopia.
Repetitive transcranial magnetic stimulation (rTMS) is one of the non-invasive stimulations had been used widely as a research tool to understand the brain functions and an established treatment modality in neuropsychiatric diseases. Theta burst stimulation (TBS) is a newer form of rTMS protocol which have a major advantage over traditional rTMS in their reduced administration duration and allowing stimulation at significantly lower intensities to attain comparable effects. TBS had been demonstrated to able to improve functions in participants with visual disorders. However, studies of its use on adult amblyopia are scarce. Due to lack of efficient treatment at present, it is of scientific significance to conduct placebo-controlled experiments on this topic. Investigators will evaluate the effect of three regimens of TBS (intermittent, continuous and sham), after one session and accumulative sessions, on visual functions of amblyopia adults shortly after treatment and 2 weeks later (lasting effect), in order to evaluate its potential role in amblyopia and find out the best paradigm for amblyopia treatment.
- Conditions
- Amblyopia
- Being tested
- Theta burst transcranial magnetic stimulation (TBS) procedure
- Keywords
- Transcranial magnetic stimulation, Amblyopia, Neuroplasticity
- Medical subject headings
- Amblyopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Theta burst transcranial magnetic stimulation (TBS) procedureDevice
The procedure includes determining the specific occipital point at which place the stimulation coil; this corresponds to the area where magnetic stimulation is most capable of inducing phosphenes or transient visual phenomena. The phosphenes are directly induced by stimulation of the visual cortex and their presence indicates that the magnetic stimulation is in the correct location. The subjects would wear a personalized swimming cap with the determined area for stimulation marked on it. The major differences between iTBS and cTBS are the frequency and interval of stimulus.
| Study group | Role | What they receive |
|---|---|---|
| Intermittent theta burst | Experimental | The total TBS time is about 1 to 3 minutes and the subjects have to look at at a visual stimulus on a computer monitor while receiving TBS and continue the visual training until 20 minutes after the treatment. In iTBS group, the subjects look at the visual stimulus with amblyopic eye while in cTBS group, subjects look at visual stimulus with non-amblyopic eye. The subjects will receive three times of stimulations in one week. The visual function evaluation includes BCVA, contrast sensitivity and stereoacuity. Visual functions will be evaluated right after TBS session (t1). Participant will receive same type of treatment for another 2 times within one week followed by visual function tests (t2). To evaluate the long-term effect, participants will be followed for another visual function tests (t3) after 2 weeks. Receives: Device: Theta burst transcranial magnetic stimulation (TBS) procedure |
| Continuous theta burst | Experimental | The total TBS time is about 1 to 3 minutes and the subjects have to look at at a visual stimulus on a computer monitor while receiving TBS and continue the visual training until 20 minutes after the treatment. In iTBS group, the subjects look at the visual stimulus with amblyopic eye while in cTBS group, subjects look at visual stimulus with non-amblyopic eye. The subjects will receive three times of stimulations in one week. The visual function evaluation includes BCVA, contrast sensitivity and stereoacuity. Visual functions will be evaluated right after TBS session (t1). Participant will receive same type of treatment for another 2 times within one week followed by visual function tests (t2). To evaluate the long-term effect, participants will be followed for another visual function tests (t3) after 2 weeks. Receives: Device: Theta burst transcranial magnetic stimulation (TBS) procedure |
| Sham theta burst | Sham comparator | The stimulus intensity in sham group is about half of that in iTBS/cTBS groups, and the subjects receive a placebo stimulation with the coil orientation tilted to 90°. The visual function evaluation includes BCVA, contrast sensitivity and stereoacuity. Visual functions will be evaluated right after TBS session (t1). Participant will receive same type of treatment for another 2 times within one week followed by visual function tests (t2). To evaluate the long-term effect, participants will be followed for another visual function tests (t3) after 2 weeks. Receives: Device: Theta burst transcranial magnetic stimulation (TBS) procedure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Objective
Change from baseline best corrected visual acuity: distance visual acuity measured for each eye at a distance of 6 m. Visual acuity scored letter-by-letter instead and lonarithm of the minimum angle of resolution (logMAR) scores were recored.
Measured: 1 month for each participant
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 May 2022
- Study start5 Jan 2023
- Primary completion17 Oct 2025
- Study completion31 Dec 2027 (estimated)
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.
- More trials run by National Taiwan University 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
- Health services research
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National Taiwan University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Tzu-Hsun Tsai, Principal investigator, National Taiwan University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05393739
- Sponsor's protocol ID
- 202106139DINC
- Status last verified
- Jul 2026
- First submitted
- 2 May 2022
- Last updated
- 20 Jul 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Transcranial Magnetic Stimulation on Visual Functions of Adult Amblyopia: a Preliminary Study
- ClinicalTrials.gov ID
- NCT05393739
- Acronym / sponsor ID
- 202106139DINC
- Conditions
- Amblyopia
- Keywords
- Transcranial magnetic stimulation, Amblyopia, Neuroplasticity
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- National Taiwan University HospitalUniversity, hospital or other
- Study start
- 5 Jan 2023 (actual)
- Primary completion
- 17 Oct 2025 (actual)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 26 May 2022 (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.
Amblyopia, with a prevalence rates of 3% in adult population, is a common cause of vision impairment. It is characterized by impaired vision in one or both eyes because of disruption of normal visual stimuli and underdevelopment of the visual cortex, leads to lifelong visual deficits affecting both monocular and binocular visual function. Common causes of amblyopia include refraction error, anisometropia, strabismus and visual deprivation arising from ptosis or congenital cataract. Our previous studies had shed light on the relationship between abnormal early visual experience, and development of later amblyopia and possible neural developmental disorders. Functional recovery is difficult when neuroplasticity slows down at the end of the critical period. To date, there is no established effective treatment for adult amblyopia.
Repetitive transcranial magnetic stimulation (rTMS) is one of the non-invasive stimulations had been used widely as a research tool to understand the brain functions and an established treatment modality in neuropsychiatric diseases. Theta burst stimulation (TBS) is a newer form of rTMS protocol which have a major advantage over traditional rTMS in their reduced administration duration and allowing stimulation at significantly lower intensities to attain comparable effects. TBS had been demonstrated to able to improve functions in participants with visual disorders. However, studies of its use on adult amblyopia are scarce. Due to lack of efficient treatment at present, it is of scientific significance to conduct placebo-controlled experiments on this topic. Investigators will evaluate the effect of three regimens of TBS (intermittent, continuous and sham), after one session and accumulative sessions, on visual functions of amblyopia adults shortly after treatment and 2 weeks later (lasting effect), in order to evaluate its potential role in amblyopia and find out the best paradigm for amblyopia treatment.
Study design
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Intermittent theta burst | Experimental | Device: Theta burst transcranial magnetic stimulation (TBS) procedureThe total TBS time is about 1 to 3 minutes and the subjects have to look at at a visual stimulus on a computer monitor while receiving TBS and continue the visual training until 20 minutes after the treatment. In iTBS group, the subjects look at the visual stimulus with amblyopic eye while in cTBS group, subjects look at visual stimulus with non-amblyopic eye. The subjects will receive three times of stimulations in one week. The visual function evaluation includes BCVA, contrast sensitivity and stereoacuity. Visual functions will be evaluated right after TBS session (t1). Participant will receive same type of treatment for another 2 times within one week followed by visual function tests (t2). To evaluate the long-term effect, participants will be followed for another visual function tests (t3) after 2 weeks. |
| Continuous theta burst | Experimental | Device: Theta burst transcranial magnetic stimulation (TBS) procedureThe total TBS time is about 1 to 3 minutes and the subjects have to look at at a visual stimulus on a computer monitor while receiving TBS and continue the visual training until 20 minutes after the treatment. In iTBS group, the subjects look at the visual stimulus with amblyopic eye while in cTBS group, subjects look at visual stimulus with non-amblyopic eye. The subjects will receive three times of stimulations in one week. The visual function evaluation includes BCVA, contrast sensitivity and stereoacuity. Visual functions will be evaluated right after TBS session (t1). Participant will receive same type of treatment for another 2 times within one week followed by visual function tests (t2). To evaluate the long-term effect, participants will be followed for another visual function tests (t3) after 2 weeks. |
| Sham theta burst | Sham comparator | Device: Theta burst transcranial magnetic stimulation (TBS) procedureThe stimulus intensity in sham group is about half of that in iTBS/cTBS groups, and the subjects receive a placebo stimulation with the coil orientation tilted to 90°. The visual function evaluation includes BCVA, contrast sensitivity and stereoacuity. Visual functions will be evaluated right after TBS session (t1). Participant will receive same type of treatment for another 2 times within one week followed by visual function tests (t2). To evaluate the long-term effect, participants will be followed for another visual function tests (t3) after 2 weeks. |
Who may qualify
- Ages
- 20 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Adult amblyopia participants, aged 20-50 years old.
- Based on inclusion criteria, there was a minimum of 2 lines difference in BCVA between the 2 eyes.
- An amblyogenic factor and history of amblyopia treatment was recorded
Key exclusion criteria (11 listed)
- Unstable vital sign
- History of brain injury and/or head trauma
- Neurological and psychiatric disease
- Seizures or family history of seizure
- Pregnancy
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 |
|---|---|---|
| Theta burst transcranial magnetic stimulation (TBS) procedureThe procedure includes determining the specific occipital point at which place the stimulation coil; this corresponds to the area where magnetic stimulation is most capable of inducing phosphenes or transient visual phenomena. The phosphenes are directly induced by stimulation of the visual cortex and their presence indicates that the magnetic stimulation is in the correct location. The subjects would wear a personalized swimming cap with the determined area for stimulation marked on it. The major differences between iTBS and cTBS are the frequency and interval of stimulus. | Device | Continuous theta burst, Intermittent theta burst, Sham theta burst |
Primary outcome
Objective
Time frame: 1 month for each participant
Change from baseline best corrected visual acuity: distance visual acuity measured for each eye at a distance of 6 m. Visual acuity scored letter-by-letter instead and lonarithm of the minimum angle of resolution (logMAR) scores were recored.
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 20 Jul 2026.
Related trials for Amblyopia
RecruitingPhase 1/2
Psilocybin for Amblyopia - Targeting Critical Periods in Humans
Amblyopia
RecruitingPhase 3
Dichoptic Treatment for Amblyopia in Children 4 to 7 Years of Age
Amblyopia
RecruitingPhase 3
Dichoptic Treatment for Amblyopia in Children 8 to 12 Years of Age
Amblyopia
Recruiting
OCT Eccentric Fixation and Amblyopia in Children
Amblyopia
Not yet recruiting
Non-invasive Induction of Metaplasticity for Amblyopia
Amblyopia, Amblyopia Unilateral
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.
Tzu-Hsun Tsai principal investigator
National Taiwan University Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Theta burst transcranial magnetic stimulation (TBS) procedure in people with Amblyopia, run by National Taiwan University Hospital at 1 site in Taiwan.
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 3 inclusion and 11 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: under way, not looking for participants, as of the sponsor's last update on 20 Jul 2026. 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 Taiwan. 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?
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?
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?
Objective (time frame: 1 month for each participant). 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 20 Jul 2026.