Natural History of MTBI-related Convergence Insufficiency & Effectiveness of Vision Therapy for MTBI-related CI

Phase 2

Not yet recruiting

• Conditions: Convergence Insufficiency

• Registration Number: NCT06848673
• Lead Sponsor: Salus University

Brief Summary

The design of this project is a pilot study, a type of feasibility study conducted in preparation for subsequent RCTs that will assess the effectiveness of office-based vergence/accommodative therapy with movement (OBVAM) for mTBI-related convergence insufficiency.

Detailed Description

The design of this project is a pilot study, a type of feasibility study conducted in preparation for subsequent RCTs that will assess the effectiveness of interventions or therapies. In this application, we refer to this pilot and feasibility study as a pilot clinical trial (PCT). This feasibility PCT aims to identify potential challenges, logistical issues, and unforeseen complications. To do this, we will examine various feasibility aspects, including recruitment and retention, randomization, intervention protocols, outcome measures, ethical considerations, safety monitoring, resource availability, and stakeholder feedback. By conducting this PCT, we can test our procedures and gather preliminary data. The primary objectives of this feasibility PCT are to 1) Determine the feasibility of conducting future full-scale RCTs by evaluating the effectiveness of a novel vergence/accommodative/move (OBVAM) therapy program for young adults with mTBI-CI and 2) Better understand the progression and stability (i.e., natural history) of mTBI-CI over the 6 weeks following enrollment.

Study Timeline

• Status Verified: 2025-02
• Study First Submitted: 2025-02-18
• Study First Submitted QC: 2025-02-21
• Last Update Submitted: 2025-02-21
• Study First Posted: 2025-02-27
• Last Update Posted: 2025-02-27
• Study Start: 2026-11-01
• Primary Completion: 2028-04-30
• Study Completion: 2028-09-30

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 100

Inclusion Criteria

• • Age 18 to 35 years inclusive

  • Medical diagnosis of mTBI or concussion > 1 month ago and no longer than 6 months ago
  • Convergence Insufficiency Symptom (CISS score) ≥ 21
  • Best-corrected VA of 20/25 or better in both eyes at distance & near
  • Willingness to wear refractive correction, if indicated
  • Random dot stereopsis of 500 arcsec or better (Randot Stereo Test)
  • Receded NPC of ≥6 cm
  • Insufficient PFV (< 15∆ or PFV blur point less than twice the near exophoria magnitude)
  • Wearing refractive correction for cycloplegic refractive errors of:
  • ≥ +1.25 D SE hyperopia or ≥ -1.00 D SE myopia in either eye
  • ≥ 1.25 D astigmatism in either eye, ≥ 1.00 D SE anisometropia
  • Astigmatism axis within ±10 degrees if magnitude is ≤1.00 D and within ±5 degrees if >1.00 D

Exclusion Criteria

• • No previous treatment for CI

  • No previous diagnosis of CI from an ophthalmologist or optometrist
  • No medications known to affect accommodation or vergence
  • Investigator & patient willing to forgo all other CI treatment other than that assigned by randomization

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Clinical Composite Measure	6 weeks	The primary outcome measure is a composite score of two key clinical measures: the near point of convergence (NPC) and positive fusional vergence at near (PFV). At the two outcome visits, each participant's performance on these clinical measures will be categorized according to the following predefined success criteria: 1) Successful: meets both criteria; a) NPC is \<6 cm and improved ≥4 cm and b) PFV meets Sheard's criterion and the blur (break, if no blur) is \>15Δ and increased ≥10Δ; 2) Improved: NPC improved ≥4 cm and PFV improved ≥10Δ; and 3) Non-Responder: Does not meet criteria for successful or improved

Secondary Outcome Measures

Name	Time	Method
Comparison of the Change in the Near Point of Convergence (NPC) break and recovery value	6 weeks	A standard near point rod will be used to measure the ability to converge the eyes. We will measure the NPC break (when double vision occurs) and the NPC recovery (when single vision is restored) . A comparison of the change in the break and recovery between the immediate and the delayed groups will be analyzed from baseline to to the first outcome visit (after 6 weeks).
Comparison of the Change in Positive Fusional Vergence after 6 weeks between the Two Groups	6 weeks	A hand-held prism bar will be used to assess positive fusional vergence (PFV) at baseline and after 6 weeks. We will measure the PFV break (when double vision occurs) and the PFV recovery (when single vision is restored) . A comparison of the change in the break and recovery between the immediate and the delayed groups will be analyzed from baseline to to the first outcome visit (after 6 weeks).