Recruiting

Non-invasive Brain StimulationNon-invasive Brain Stimulation for Treating Symptomatic Convergence Insufficiency

Sponsor:

Midwestern University

Code:

NCT05877560

Conditions

Convergence Insufficiency

Eligibility Criteria

Sex: All

Age: 18 - 40

Healthy Volunteers: Accepted

Interventions

Anodal-Transcranial Direct Current Stimulation

Office-Based Vergence/Accommodative Therapy

Sham Transcranial Direct Current Stimulation

Study Details

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.

Conditions

Convergence Insufficiency

Study ID

NCT05877560

Start date

Mar 1, 2025

Status verified date

Nov, 2024

Completion date

Dec 31, 2028

Anticipated

Primary completion date

Dec 31, 2028

Anticipated

Eligibility Criteria

Sex: All

Age: 18 - 40

Healthy Volunteers: Accepted

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

Enrollment

150 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: NIBS-OBVAT

8 sessions of non-invasive brain stimulation with 8 weeks of office-based vergence/accommodative therapy.

active comparator: NIBS

8 sessions of non-invasive brain stimulation only.

sham comparator: OBVAT

8 sessions of sham stimulation with 8 weeks of office-based vergence/accommodative therapy.

Interventions

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.

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.

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 measure

Near Point of Convergence (NPC) [ Time Frame: 4 weeks, 6 weeks, and 8 weeks during treatment; 6 months and 12 months post-treatment ]
Positive Fusional Vergence (PFV) [ Time Frame: 4 weeks, 6 weeks, and 8 weeks during treatment; 6 months and 12 months post-treatment ]

Central Contacts and Locations

Central contacts

Arijit Chakraborty, PhD

630-960-3172 achakr@midwestern.edu

Adrienne C Quan, OD

630-960-3183 aquan@midwestern.edu

Locations

Midwestern University Eye Institute

Recruiting

Downers Grove, Illinois, United States, 60515

Contacts

Sherri Olsen

1-630-515-7368 solsen@midwestern.edu

More Information

Sponsor

Midwestern University

Last update posted

Dec 2, 2024

Last verified

Nov, 2024

Keywords

Convergence Insufficiency
Non-invasive Brain Stimulation
Office-Based Vergence/Accommodative Therapy
Frontal Eye Fields
Transcranial Direct Current Stimulation

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-08. This information was provided to ClinicalTrials.gov by Midwestern University on 2024-12-02.