Non-invasive Brain Stimulation for Treating Symptomatic Convergence Insufficiency

Not Applicable

Recruiting

• Conditions: Convergence Insufficiency
• Interventions: Device: Anodal-Transcranial Direct Current Stimulation; Behavioral: Office-Based Vergence/Accommodative Therapy; Device: Sham Transcranial Direct Current Stimulation

• Registration Number: NCT05877560
• Lead Sponsor: Midwestern University

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:

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-05-17
• Study First Submitted QC: 2023-05-17
• Study First Posted: 2023-05-26
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-27
• Last Update Posted: 2024-12-02
• Study Start: 2025-03-01
• Primary Completion: 2028-12-31
• Study Completion: 2028-12-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 150

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
NIBS-OBVAT	Anodal-Transcranial Direct Current Stimulation	8 sessions of non-invasive brain stimulation with 8 weeks of office-based vergence/accommodative therapy.
NIBS-OBVAT	Office-Based Vergence/Accommodative Therapy	8 sessions of non-invasive brain stimulation with 8 weeks of office-based vergence/accommodative therapy.
NIBS	Anodal-Transcranial Direct Current Stimulation	8 sessions of non-invasive brain stimulation only.
OBVAT	Office-Based Vergence/Accommodative Therapy	8 sessions of sham stimulation with 8 weeks of office-based vergence/accommodative therapy.
OBVAT	Sham Transcranial Direct Current Stimulation	8 sessions of sham stimulation with 8 weeks of office-based vergence/accommodative therapy.

Primary Outcome Measures

Name	Time	Method
Near Point of Convergence (NPC)	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)	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 Outcome Measures

Name	Time	Method
Convergence Insufficiency Symptoms Survey (CISS)	8 weeks during treatment; 6 months and 12 months post-treatment	A change in the CISS score from baseline after treatment. The minimum score is 0 and the maximum score is 60. Lower scores indicate a better outcome.

Trial Locations

Locations (1)

Midwestern University Eye Institute; 🇺🇸 Downers Grove, Illinois, United States