Trial Search Results

Interventions for Convergence Insufficiency in Concussed Children

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.

Stanford is currently not accepting patients for this trial.

Lead Sponsor:

Mitchell Scheiman

Collaborator: Ohio State University

Stanford Investigator(s):


  • Behavioral: Standard Community Concussion Care (SC)
  • Behavioral: SC plus Simple Convergence Exercises (SC+)
  • Behavioral: SC plus Office-based Vergence/Accommodative Therapy (SC+OBVAT)


Phase 3


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

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

11. Inability to comprehend and/or perform any study-related, clinical vision function

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

Ages Eligible for Study

11 Years - 17 Years

Genders Eligible for Study


Not currently accepting new patients for this trial

Contact Information

Stanford University
School of Medicine
300 Pasteur Drive
Stanford, CA 94305
Gerald Grant, MD
Not Recruiting