Interventions for Convergence Insufficiency in Concussed Children

Interventions for Convergence Insufficiency in Concussed Children (ICONICC)

The ICONICC Study is a randomized controlled clinical trial designed to compare the proportion of successful treatment outcomes between children assigned to standard concussion care only, standard concussion care plus simple convergence procedures, or standard concussion care plus office-based vergence/accommodative therapy in children aged 11 to 17 years with symptomatic post-concussion syndrome. Children with post-concussion syndrome (4-12 weeks post-concussion injury) and symptomatic CI will be randomized to a 12-week treatment program of either standard concussion care (SC), SC plus simple convergence procedures (SC+), or SC plus office-based vergence/accommodative therapy SC+OBVAT (1:1:1 ratio).

The study will also compare the effect of treatment on clinical measures of both accommodation and vergence, symptom level/burden, health-related quality of life, clinical measures of saccadic eye movement, and objective eye movement measurements of disparity vergence, saccadic function, and accommodative function. The attainment of objective eye movement measures provides an opportunity to understand the underlying neurophysiology of the vergence and accommodative systems. Objective eye movement recordings are powerful because of the rich foundation from primate single-cell recordings that show a direct correlation with vergence and accommodative parameters in the supraoculomotor area of midbrain2, 3 and the oculomotor vermis of the cerebellum.4, 5 Thus, a combined approach of acquiring both clinical vision function measures and objective eye movement recordings in children with PCS-CI may lead to better characterization of the oculomotor phenotype with subsequent improved and personalized therapeutic interventions.

Objectives:

A group of 264 diverse children, ages 11 to 17 years, with post-concussion syndrome (4-12 weeks post-concussion injury) and symptomatic CI will be enrolled from 6 sites from across the United States, will be randomized to 12 weeks of: 1) standard care (SC), 2) SC plus simple convergence exercises (SC+), and 3) SC plus office-based vergence/ accommodative therapy (SC+OBVAT).

Primary Objective: To compare the effectiveness of SC, SC+, SC plus office-based vergence/accommodative therapy for improving a composite outcome measure of clinical findings (near point of convergence and positive fusional vergence at near) in children 11-17 years of age with concussion-related CI after 12 weeks of treatment.

• Secondary outcome measures
• Objective measures of disparity vergence, accommodation, saccades, and smooth pursuit
• Quality of life measures
• Convergence Insufficiency Symptom Survey Concussion Version (CISS-CON)
• PedsQL Version 4 For participants in any treatment group who not "successful" based on the composite score described above, additional/different treatment will be offered as an option after the primary outcome examination

Inclusion Criteria:

ICONICC will enroll children of all races and will adhere to a policy of equitability. To be eligible to participate in ICONICC, the child must meet all of the following criteria:

1. Medical diagnosis of concussion of at least 4 weeks and no longer than 12 weeks since known date of injury

2. Age 11 to 17 years

3. Gender - any

4. CI Symptom Survey (CISS) score ≥ 16

5. Exophoria at near at least 4∆ greater than at far

6. Receded near point of convergence (NPC) of greater than 6 cm break

7. Insufficient positive fusional vergence (PFV) at near (i.e., failing Sheard's criterion1 or PFV ≤15∆ base-out break)

8. Best-corrected distance visual acuity of 20/25 or better in each eye

9. Random dot stereopsis appreciation of 500 seconds of arc or better using the Randot Stereotest

10. Willing to wear refractive correction for any of the following uncorrected refractive errors based on a cycloplegic refraction performed at the eligibility examination. (Correction must be worn for at least 2 weeks):

    • Myopia > -0.75 D spherical equivalent in either eye
    • Hyperopia > 2.00 D spherical equivalent in either eye
    • Anisometropia > 0.75D spherical equivalent or ≥ 1.50 D in any meridian
    • Astigmatism > 1.00 D in either eye

11. Willing to discontinue BI prism or a plus add at near for duration of study (must discontinue at least 2 weeks before eligibility examination)

12. Parent and child understand protocol and are willing to accept randomization

13. Normal pupillary responses

Exclusion Criteria:

1. Any strabismus at distance
2. Constant strabismus at near
3. Limitation on versions/ductions due to restrictive or paretic strabismus
4. Esophoria of ≥ 2∆ at distance
5. Vertical heterophoria ≥ 2∆ at distance or near
6. ≥ 2 line interocular difference in best-corrected visual acuity
7. Manifest or latent nystagmus
8. History of surgery or botulinum toxin for strabismus or any type of refractive surgery
9. Previous diagnosis of CI by an eye care professional before concussion
10. Diseases known to affect accommodation, vergence, or ocular motility such as multiple sclerosis, Graves orbitopathy, myasthenia gravis, diabetes mellitus, Parkinson's disease
11. Inability to comprehend and/or perform any study-related, clinical vision function test
12. Household member enrolled in present ICONICC study or treated within the past 6 months with any form of office-based vergence/accommodative therapy or home-based vergence therapy (e.g., computerized vergence therapy)
13. Household member is an eye care professional, ophthalmic technician, ophthalmology or optometry resident or fellow, or optometry student