Convergence InsufficiencyNCT05603962
The Effectiveness of Visual Training in Convergence Insufficiency Patients
A study testing Visual training in people with Convergence Insufficiency, run by National Taiwan University Hospital at 1 site in Taiwan.
Trial summary
Convergence insufficiency (CI) is one of the most common binocular vision disorders. The prevalence of CI ranges from 3% to 6% in school-aged children. CI symptoms include visual fatigue, headache, blurred vision, and diplopia and could be caused while using near-distance viewing. Read more about this study
- Who is it for?
- Ages 9 to 30 years
- Conditions the study is for
- Convergence Insufficiency
- What is being tested?
- Visual training
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 1 siteTaiwan
- Study dates
- 6 Mar 2023to 26 Jun 2024
- 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 9 to 30 years
- All sexes
- No healthy volunteers
- Child, Adult
Who may be able to join
- The overall score of CI symptom survey ≥ 16 (9-18 years old) or ≥ 21 (19-30 years old)
- The break point of near point of convergence (NPC) ≥ 6 cm
- Exophoria at near distances be at least 4∆ higher than at far distances
- Near positive fusional vergence (PFV) ≤ 15∆ or failing Sheard's criterion at near.
Who cannot join
- The best corrected visual acuity (BCVA) of < 20/25 in each eye at far and near distances
- Amblyopia patients or the difference of BCVA between the two eyes ≥ 2 lines
- Constant strabismus patients
- History of strabismus surgery or refractive surgery
- Systemic diseases that would affect binocular vision
- Acquired brain injury or neurological disorder.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: The Effectiveness of Visual Training Using Prisms on Visual Symptoms and Binocular Vision in Convergence Insufficiency Patients
Convergence insufficiency (CI) is one of the most common binocular vision disorders. The prevalence of CI ranges from 3% to 6% in school-aged children. CI symptoms include visual fatigue, headache, blurred vision, and diplopia and could be caused while using near-distance viewing. These symptoms might become more severe with increasing need to perform near-distance tasks. Long-term visual symptoms could result in a negative impact on learning behaviors and work performance in patients. Nowadays, visual training is the main type of management for CI patients clinically; however, the existing training protocol required patients to make several visits to the clinic for visual training, which might increase the burden for patients and result in higher failures in training. Therefore, this study will use a simple training method by utilizing prisms for CI patients to train at home, then compare visual symptoms and binocular vision after the training. In stage I of this study, investigators will recruit 60 symptomatic CI participants aged 9 to 30 years old to do a 6-week visual training with the prisms (15 min/time, 3 times/week). The post-training outcomes will be collected at week 4 and week 6. In stage II, all of the participants will be randomly divided into the "stop training group" and the "continue training group." The participants in the "continue training group" will have the same 6-week prism training and in the "stop training group" will stop all the prism training during this period. The final post-training outcomes of all the participants will be collected again at week 12. In this study, investigators will investigate the effectiveness of the prisms training for 6 weeks and for 12 weeks on visual symptoms and binocular vision in CI patients, and evaluate whether the training effect will be affected by stopping training after 6 weeks.
- Conditions
- Convergence Insufficiency
- Being tested
- Visual training
- Keywords
- Visual training, Prism, Binocular vision
- Medical subject headings
- Ocular Motility Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Visual trainingBehavioural
Visual training is the main type of management for CI patients clinically; however, the existing training protocol required patients to make several visits to the clinic for visual training, which might increase the burden for patients and result in higher failures in training. Therefore, this study will use a simple training method by utilizing prisms for CI patients to train at home, then compare visual symptoms and binocular vision after the training.
| Study group | Role | What they receive |
|---|---|---|
| Stop training group | Active comparator | Home-base prism training during week 1-6 --> then stop training during week 7-12 --> endpoint data collected at week 12 Receives: Behavioral: Visual training |
| Continune training group | Experimental | Home-base prism training during week 1-12 --> endpoint data collected at week 12 Receives: Behavioral: Visual training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Binocular vision and visual function evaluation
Change from baseline best corrected visual acuity: distance visual acuity measured for each eye at a distance of 6 m and at near 40 cm for each eye will be measured using Snellen charts. NPC and the amplitude of accommodation will be measured using Royal Air Force (RAF) rule. Stereoacuity will be measured by the Random dot stereotest.
Measured: 12 weeks 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 posted3 Nov 2022
- Study start6 Mar 2023
- Primary completion26 Jun 2024
- Study completion26 Jun 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Convergence InsufficiencyStudies 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
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 12 participants (actual)
Sponsor and investigators
- Lead sponsor
- National Taiwan University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Tzu-Hsun Tsai, PhD, Principal investigator, National Taiwan University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05603962
- Sponsor's protocol ID
- 202207058RINB
- Status last verified
- Mar 2023
- First submitted
- 25 Oct 2022
- Last updated
- 3 Dec 2024
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Dec 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effectiveness of Visual Training Using Prisms on Visual Symptoms and Binocular Vision in Convergence Insufficiency Patients
- ClinicalTrials.gov ID
- NCT05603962
- Acronym / sponsor ID
- 202207058RINB
- Conditions
- Convergence Insufficiency
- Keywords
- Visual training, Prism, Binocular vision
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 12 participants (actual)
- Lead sponsor
- National Taiwan University HospitalUniversity, hospital or other
- Study start
- 6 Mar 2023 (actual)
- Primary completion
- 26 Jun 2024 (actual)
- Study completion
- 26 Jun 2024 (actual)
- First posted
- 3 Nov 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.
Convergence insufficiency (CI) is one of the most common binocular vision disorders. The prevalence of CI ranges from 3% to 6% in school-aged children. CI symptoms include visual fatigue, headache, blurred vision, and diplopia and could be caused while using near-distance viewing. These symptoms might become more severe with increasing need to perform near-distance tasks. Long-term visual symptoms could result in a negative impact on learning behaviors and work performance in patients. Nowadays, visual training is the main type of management for CI patients clinically; however, the existing training protocol required patients to make several visits to the clinic for visual training, which might increase the burden for patients and result in higher failures in training. Therefore, this study will use a simple training method by utilizing prisms for CI patients to train at home, then compare visual symptoms and binocular vision after the training. In stage I of this study, investigators will recruit 60 symptomatic CI participants aged 9 to 30 years old to do a 6-week visual training with the prisms (15 min/time, 3 times/week). The post-training outcomes will be collected at week 4 and week 6. In stage II, all of the participants will be randomly divided into the "stop training group" and the "continue training group." The participants in the "continue training group" will have the same 6-week prism training and in the "stop training group" will stop all the prism training during this period. The final post-training outcomes of all the participants will be collected again at week 12. In this study, investigators will investigate the effectiveness of the prisms training for 6 weeks and for 12 weeks on visual symptoms and binocular vision in CI patients, and evaluate whether the training effect will be affected by stopping training after 6 weeks.
Study design
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Stop training group | Active comparator | Behavioral: Visual trainingHome-base prism training during week 1-6 --> then stop training during week 7-12 --> endpoint data collected at week 12 |
| Continune training group | Experimental | Behavioral: Visual trainingHome-base prism training during week 1-12 --> endpoint data collected at week 12 |
Who may qualify
- Ages
- 9 to 30 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult
Key inclusion criteria (4 listed)
- The overall score of CI symptom survey ≥ 16 (9-18 years old) or ≥ 21 (19-30 years old)
- The break point of near point of convergence (NPC) ≥ 6 cm
- Exophoria at near distances be at least 4∆ higher than at far distances
- Near positive fusional vergence (PFV) ≤ 15∆ or failing Sheard's criterion at near.
Key exclusion criteria (6 listed)
- The best corrected visual acuity (BCVA) of < 20/25 in each eye at far and near distances
- Amblyopia patients or the difference of BCVA between the two eyes ≥ 2 lines
- Constant strabismus patients
- History of strabismus surgery or refractive surgery
- Systemic diseases that would affect binocular vision
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 |
|---|---|---|
| Visual trainingVisual training is the main type of management for CI patients clinically; however, the existing training protocol required patients to make several visits to the clinic for visual training, which might increase the burden for patients and result in higher failures in training. Therefore, this study will use a simple training method by utilizing prisms for CI patients to train at home, then compare visual symptoms and binocular vision after the training. | Behavioural | Continune training group, Stop training group |
Primary outcome
Binocular vision and visual function evaluation
Time frame: 12 weeks for each participant
Change from baseline best corrected visual acuity: distance visual acuity measured for each eye at a distance of 6 m and at near 40 cm for each eye will be measured using Snellen charts. NPC and the amplitude of accommodation will be measured using Royal Air Force (RAF) rule. Stereoacuity will be measured by the Random dot stereotest.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Dec 2024.
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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.
Tzu-Hsun Tsai, PhD 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 Visual training in people with Convergence Insufficiency, 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 4 inclusion and 6 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: finished, as of the sponsor's last update on 3 Dec 2024. 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. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
Binocular vision and visual function evaluation (time frame: 12 weeks 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 3 Dec 2024.