NCT05877560 · Midwestern University
Non-invasive Brain Stimulation for Treating Symptomatic Convergence Insufficiency
(NIBSCI)
What this study is about
The goal of this randomly assigned controlled trial is to test the effectiveness of non-invasive brain stimulation in treating adults with symptomatic convergence insufficiency compared to vergence/accommodative therapy. The main questions it aims to answer are: 1.
View original scientific description
The goal of this randomized controlled trial is to test the effectiveness of non-invasive brain stimulation in treating adults with symptomatic convergence insufficiency compared to vergence/accommodative therapy. The main questions it aims to answer are: 1. Can non-invasive brain stimulation shorten the treatment time of office-based vergence/accommodative therapy for convergence insufficiency? 2. Is non-invasive brain stimulation alone just as effective as office-based vergence/accommodative therapy in treating convergence insufficiency? The investigators hypothesize that non-invasive brain stimulation will shorten the treatment time from 12 weeks to 8 weeks of office-based vergence/accommodative therapy and that non-invasive brain stimulation alone would be equally effective as office-based vergence/accommodative therapy in improving symptomatic convergence insufficiency. Participants will be randomized into one of three treatment groups: 1. Non-invasive brain stimulation with office-based vergence/accommodative therapy. 2. Sham stimulation with office-based vergence/accommodative therapy. 3. Non-invasive brain stimulation only. Researchers will compare baseline measurements of near point of convergence (NPC) and positive fusional vergence (PFV) to post-treatment measurements for each group.
Interventions
DEVICE
Anodal-Transcranial Direct Current Stimulation
Non-invasive brain stimulation will involve the use of anodal transcranial direct current stimulation to apply a 2 milliamp current over the left frontal eye field for approximately 20 minutes with a ramp up to the maximum programmed current and ramp down of 20 seconds.
BEHAVIORAL
Office-Based Vergence/Accommodative Therapy
Office-based vergence accommodative therapy involves weekly in-office appointments with the therapist lasting approximately 60 minutes per visit during which time in-office procedures will be performed, and home therapy procedures will be demonstrated. Participants will be prescribed 15 minutes of home reinforcement therapy procedures to be completed 5 days per week. Therapy will consist of two phases adapted from the Convergence Insufficiency Treatment Trial (CITT). Therapy procedures will include gross convergence, accommodation. non-computer based vergence, and computer-based vergence.
DEVICE
Sham Transcranial Direct Current Stimulation
Sham transcranial direct current stimulation will be applied over the left frontal eye field with the current ramping up for 20 seconds before ramping down for 20 seconds. The 2 milliamp current stimulation will occur for only a few seconds at the start and at the end of the 20 minutes.
Primary outcome measures
Near Point of Convergence (NPC)
Time frame: 4 weeks, 6 weeks, and 8 weeks during treatment; 6 months and 12 months post-treatment
A change in the NPC break and recovery values measured in centimeters (cm) from baseline after treatment.
Positive Fusional Vergence (PFV)
Time frame: 4 weeks, 6 weeks, and 8 weeks during treatment; 6 months and 12 months post-treatment
A change in the near PFV blur, break, and recovery values measured in prism diopters (∆) from baseline after treatment.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Best-corrected visual acuity of \> 20/25 in each eye at distance and near
- Exophoria at near at least 4∆ greater than at far
- Receded near point of convergence of \> 6 cm break
- Insufficient positive fusional vergence at near (\< 15∆ base-out blur or break)
- CISS score of 16 and greater for children or 21 and greater for adults
- Have had a dilated fundus examination within the last 12 months
- Informed consent and willingness to participate in the study and be randomized
Exclusion criteria
- Previously treated for convergence insufficiency with home- or office-based vergence/accommodative therapy
- Amblyopia (\> 2-line difference in best-corrected visual acuity between the two eyes)
- Constant strabismus
- History of strabismus surgery
- Convergence insufficiency secondary to acquired brain injury or neurological disorder
- Manifest or latent nystagmus
- Systemic disease known to affect accommodation, vergence, and ocular motility including multiple sclerosis, Graves disease, myasthenia gravis, Parkinson's disease, cerebral palsy, and diabetes
- Developmental disability, attention deficit hyperactivity disorder (ADHD), learning disability or cognitive dysfunction that would interfere with treatment
- Taking medications that can affect normal neurological function including antipsychotics, antiepileptics, and opioids
- Presence of metal or electronic implants in or on the body, including pacemakers
Where
- Downers Grove, Illinois
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Dec 2, 2024 · Source of record for eligibility and locations