Clinical trial NCT05877560: Non-invasive Brain Stimulation for Treating Symptomatic Convergence Insufficiency
Official title: A Randomized Controlled Study Using Non-invasive Brain Stimulation to Facilitate the Effectiveness of Vergence/Accommodative Therapy in Symptomatic Convergence Insufficiency
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Convergence Insufficiency
Keywords: Convergence Insufficiency
Non-invasive Brain Stimulation
Office-Based Vergence/Accommodative Therapy
Frontal Eye Fields
Transcranial Direct Current Stimulation
Lead sponsor: Midwestern University
Sponsor class: OTHER
First posted: 2023-05-26
Enrollment: 150
Sex: ALL
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.


Eligibility criteria: 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

Primary outcomes:
measure: Near Point of Convergence (NPC)
timeFrame: 4 weeks, 6 weeks, and 8 weeks during treatment; 6 months and 12 months post-treatment
measure: Positive Fusional Vergence (PFV)
timeFrame: 4 weeks, 6 weeks, and 8 weeks during treatment; 6 months and 12 months post-treatment
Secondary outcomes:
measure: Convergence Insufficiency Symptoms Survey (CISS)
timeFrame: 8 weeks during treatment; 6 months and 12 months post-treatment
Other outcomes:
Locations:
city: Downers Grove
country: United States
facility: Midwestern University Eye Institute
state: Illinois
Study officials:
References:
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