A Randomized Controlled Study Using Non-invasive Brain Stimulation to Facilitate the Effectiveness of Vergence/Accommodative Therapy in Symptomatic Convergence Insufficiency
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Midwestern University
- Enrollment
- 150
- Locations
- 1
- Primary Endpoint
- Near Point of Convergence (NPC)
Study Overview
Brief Summary
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:
- Can non-invasive brain stimulation shorten the treatment time of office-based vergence/accommodative therapy for convergence insufficiency?
- 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:
- Non-invasive brain stimulation with office-based vergence/accommodative therapy.
- Sham stimulation with office-based vergence/accommodative therapy.
- 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.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Double (Participant, Outcomes Assessor)
Eligibility Criteria
- Ages
- 18 Years to 40 Years (Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
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
Arms & Interventions
NIBS-OBVAT
8 sessions of non-invasive brain stimulation with 8 weeks of office-based vergence/accommodative therapy.
Intervention: Anodal-Transcranial Direct Current Stimulation (Device)
NIBS-OBVAT
8 sessions of non-invasive brain stimulation with 8 weeks of office-based vergence/accommodative therapy.
Intervention: Office-Based Vergence/Accommodative Therapy (Behavioral)
NIBS
8 sessions of non-invasive brain stimulation only.
Intervention: Anodal-Transcranial Direct Current Stimulation (Device)
OBVAT
8 sessions of sham stimulation with 8 weeks of office-based vergence/accommodative therapy.
Intervention: Office-Based Vergence/Accommodative Therapy (Behavioral)
OBVAT
8 sessions of sham stimulation with 8 weeks of office-based vergence/accommodative therapy.
Intervention: Sham Transcranial Direct Current Stimulation (Device)
Outcomes
Primary Outcomes
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.
Secondary Outcomes
- Convergence Insufficiency Symptoms Survey (CISS)(8 weeks during treatment; 6 months and 12 months post-treatment)
Investigators
Arijit Chakraborty
Assistant Director of Research
Midwestern University