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Trial record 1 of 1 for:    IXT2
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Observation Versus Occlusion Therapy for Intermittent Exotropia (IXT2)

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ClinicalTrials.gov Identifier: NCT01032330
Recruitment Status : Completed
First Posted : December 15, 2009
Results First Posted : May 8, 2019
Last Update Posted : May 19, 2020
Sponsor:
Collaborators:
Pediatric Eye Disease Investigator Group
National Eye Institute (NEI)
Information provided by (Responsible Party):
Jaeb Center for Health Research

Brief Summary:

The present study is being conducted to assess the natural history of intermittent exotropia and to establish the effectiveness of occlusion in its treatment.

Study Objectives:

  • To determine the effectiveness of occlusion for the treatment of intermittent exotropia among patients aged 3 to < 11 years who have baseline near stereoacuity of 400 arcsec or better by Preschool Randot stereotest
  • To determine the natural history of intermittent exotropia among patients aged 3 to < 11 years who have baseline near stereoacuity of 400 arcsec or better by Preschool Randot stereotest

Condition or disease Intervention/treatment Phase
Exotropia Device: occlusion treatment Not Applicable

Show Show detailed description

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 611 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Randomized Clinical Trial of Observation Versus Occlusion Therapy for Intermittent Exotropia
Study Start Date : January 2010
Actual Primary Completion Date : December 2015
Actual Study Completion Date : December 2015

Arm Intervention/treatment
No Intervention: Observation
Patients randomized to the observation group will receive no treatment (other than refractive correction).
Active Comparator: Occlusion Therapy
Patients randomized to the occlusion treatment group will receive occlusion (patching) for 3 hours per day for at least 3 months. Choice of which eye to occlude, or whether to alternate daily, is at investigator's discretion.
Device: occlusion treatment
Patients randomized to the occlusion treatment group will receive occlusion (patching) for 3 hours per day for at least 3 months. Choice of which eye to occlude, or whether to alternate daily, is at investigator's discretion.
Other Names:
  • occlusion therapy
  • patching




Primary Outcome Measures :
  1. Deterioration by 6 Months - Older Cohort [ Time Frame: 6 months ]
    The primary outcome measure for this study was whether the participant's condition had deteriorated within 6 months after randomization. Deterioration was defined as meeting one or both of the following criteria during a masked examination at either the 3-month or 6-month visit: 1) a constant exotropia (throughout the exam) of 10∆ or greater at distance and near by SPCT, confirmed by a retest, or 2) loss of near stereoacuity of 2 octaves (0.6 log arcsec) or more from the better of a test and retest of Preschool Randot stereoacuity at baseline, confirmed by a retest. In addition, participants were classified as deteriorated for the primary analysis if they started using non-randomized treatment (i.e., any treatment in the observation group; any treatment other than patching in the patching group) without first meeting one of the two protocol-specified deterioration criteria.

  2. Deterioration by 3 Years - Older Cohort [ Time Frame: 3 years ]
    The primary outcome measure for this study was whether the participant's condition had deteriorated within 3 years after randomization. Deterioration was defined as meeting one or both of the following criteria during any masked examination between 3 months and 3 years after randomization: 1) a constant exotropia (throughout the exam) of 10∆ or greater at distance and near by SPCT, confirmed by a retest, or 2) loss of near stereoacuity of 2 octaves (0.6 log arcsec) or more from the better of a test and retest of Preschool Randot stereoacuity at baseline, confirmed by a retest. In addition, participants were classified as deteriorated for the primary analysis if they started using non-randomized treatment (i.e., any treatment in the observation group; any treatment other than patching in the patching group) without first meeting one of the two protocol-specified deterioration criteria.

  3. Deterioration by 6 Months - Younger Cohort [ Time Frame: 6 months ]
    The primary outcome measure was deterioration of the intermittent exotropia (IXT) within 6 months after randomization. Motor deterioration was defined as a constant exotropia of 10 D or more at distance and near by SPCT, confirmed by a retest, at either the 3- or 6-month visit.

  4. Deterioration by 3 Years - Younger Cohort [ Time Frame: 3 years ]
    The primary outcome measure was deterioration of the intermittent exotropia (IXT) within 6 months after randomization. Motor deterioration was defined as a constant exotropia of 10 D or more at distance and near by SPCT, confirmed by a retest, during any masked examination between 3 months and 3 years after randomization.


Secondary Outcome Measures :
  1. Distance Stereoacuity - 3 Years [ Time Frame: Between baseline and 3 years ]

    Stereoacuity scores (seconds of arc) were calculated based on the Randot Preschool stereoacuity test (scores: 800, 400, 200, 100, 60 and 40). Seconds of arc refers to the visual angle that is being measured in order to determine depth perception. Lower scores indicate better stereoacuity.

    A logarithm base 10 transformation was used to convert stereoacuity scores to the log scale to calculate descriptive statistics (reported as log of seconds of arc, or log arcsec). The stereoacuity at distance is reported at 3 years, as is the change in distance stereoacuity from baseline to 3 years. Both were reported as log of seconds of arc, or log arcsec. For change in stereo, positive change indicates improvement in stereo.


  2. Near Stereoacuity - 6 Months [ Time Frame: 6 months ]

    Stereoacuity scores (seconds of arc) were calculated based on the Randot Preschool stereoacuity test (scores: 800, 400, 200, 100, 60 and 40). Seconds of arc refers to the visual angle that is being measured in order to determine depth perception. Lower scores indicate better stereoacuity.

    A logarithm base 10 transformation was used to convert stereoacuity scores to the log scale to calculate descriptive statistics (reported as log of seconds of arc, or log arcsec). The stereoacuity at near is reported at 3 years, as is the change in near stereoacuity from baseline to 3 years. Both were reported as log of seconds of arc, or log arcsec.

    Outcome based on initial testing regardless of whether a retest was completed for suspected deterioration. Change is calculated as baseline level minus 6-month level. For change in stereo, positive change indicates improvement in stereo.


  3. Near Stereoacuity - 3 Years [ Time Frame: between baseline and 3 years ]

    Stereoacuity scores (seconds of arc) were calculated based on the Randot Preschool stereoacuity test (scores: 800, 400, 200, 100, 60 and 40). Seconds of arc refers to the visual angle that is being measured in order to determine depth perception. Lower scores indicate better stereoacuity.

    A logarithm base 10 transformation was used to convert stereoacuity scores to the log scale to calculate descriptive statistics (reported as log of seconds of arc, or log arcsec). The stereoacuity at near is reported at 3 years, as is the change in near stereoacuity from baseline to 3 years. Both were reported as log of seconds of arc, or log arcsec. For change in stereo, positive change indicates improvement in stereo.


  4. Exotropia Control at Distance - 6 Months [ Time Frame: 6 months ]

    Change in control is calculated as baseline level minus 3-year level, so positive change = improvement. Scale Range: 0 to 5. Improvement in control was defined as an improvement of 3 points based on the 3-point threshold for real change.

    Numeric values for exotropia control were assigned so that the following categories were created:

    Not applicable (no exodeviation) 0: No exotropia unless dissociated, recovers <1 secs (phoria)

    1. No exotropia unless dissociated, recovers 1-5 secs
    2. No exotropia unless dissociated, recovers >5 secs
    3. Exotropia <50% of 30-second observation
    4. Exotropia >50% of 30-second observation
    5. Constant exotropia

    Lower scores indicate better control.


  5. Exotropia Control at Distance - 3 Years [ Time Frame: 3 years ]

    Change in control is calculated as baseline level minus 3-year level, so positive change = improvement. Scale Range: 0 to 5. Improvement in control was defined as an improvement of 3 points based on the 3-point threshold for real change.

    Numeric values for exotropia control were assigned so that the following categories were created:

    Not applicable (no exodeviation) 0: No exotropia unless dissociated, recovers <1 secs (phoria)

    1. No exotropia unless dissociated, recovers 1-5 secs
    2. No exotropia unless dissociated, recovers >5 secs
    3. Exotropia <50% of 30-second observation
    4. Exotropia >50% of 30-second observation
    5. Constant exotropia

    Lower scores indicate better control.


  6. Exotropia Control at Near - 6 Months [ Time Frame: 6 months ]

    Change in control is calculated as baseline level minus 3-year level, so positive change = improvement. Scale Range: 0 to 5. Improvement in control was defined as an improvement of 3 points based on the 3-point threshold for real change.

    Numeric values for exotropia control were assigned so that the following categories were created:

    Not applicable (no exodeviation) 0: No exotropia unless dissociated, recovers <1 secs (phoria)

    1. No exotropia unless dissociated, recovers 1-5 secs
    2. No exotropia unless dissociated, recovers >5 secs
    3. Exotropia <50% of 30-second observation
    4. Exotropia >50% of 30-second observation
    5. Constant exotropia

    Lower scores indicate better control.


  7. Exotropia Control at Near - 3 Years [ Time Frame: 3 years ]

    Change in control is calculated as baseline level minus 3-year level, so positive change = improvement. Scale Range: 0 to 5. Improvement in control was defined as an improvement of 3 points based on the 3-point threshold for real change.

    Numeric values for exotropia control were assigned so that the following categories were created:

    Not applicable (no exodeviation) 0: No exotropia unless dissociated, recovers <1 secs (phoria)

    1. No exotropia unless dissociated, recovers 1-5 secs
    2. No exotropia unless dissociated, recovers >5 secs
    3. Exotropia <50% of 30-second observation
    4. Exotropia >50% of 30-second observation
    5. Constant exotropia

    Lower scores indicate better control.


  8. PACT Exodeviation at Distance - 6 Months [ Time Frame: 6 months ]

    The prism and alternate cover test (PACT) is used to measure the angle of strabismus, or deviation, in prism diopters. This is measured separately at distance and at near. Smaller numbers are better because they indicate a smaller angle of deviation. For change in PACT, positive change indicates improvement (i.e. decrease in angle over time).

    log arcsec = logarithm of seconds of arc; Δ = prism diopter


  9. PACT at Distance - 3 Years [ Time Frame: 3 years ]

    The prism and alternate cover test (PACT) is used to measure the angle of strabismus, or deviation, in prism diopters. This is measured separately at distance and at near. Smaller numbers are better because they indicate a smaller angle of deviation. For change in PACT, positive change indicates improvement (i.e. decrease in angle over time). Improvement in PACT at distance was defined as a decrease of ≥8∆ because this amount exceed the repeatability coefficient of 7.2∆ for PACT angles larger than 20∆ at distance.

    log arcsec = logarithm of seconds of arc; Δ = prism diopter


  10. PACT at Near - 6 Months [ Time Frame: 6 months ]

    The prism and alternate cover test (PACT) is used to measure the angle of strabismus, or deviation, in prism diopters. This is measured separately at distance and at near. Smaller numbers are better because they indicate a smaller angle of deviation. For change in PACT, positive change indicates improvement (i.e. decrease in angle over time).

    log arcsec = logarithm of seconds of arc; Δ = prism diopter


  11. PACT at Near - 3 Years [ Time Frame: 3 years ]

    The prism and alternate cover test (PACT) is used to measure the angle of strabismus, or deviation, in prism diopters. This is measured separately at distance and at near. Smaller numbers are better because they indicate a smaller angle of deviation. For change in PACT, positive change indicates improvement (i.e. decrease in angle over time).

    Improvement in PACT at near was defined as a decrease of ≥13∆ because this amount exceed the repeatability coefficient of 12.8∆ for PACT angles larger than 20∆ at near.

    log arcsec = logarithm of seconds of arc; Δ = prism diopter




Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


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Ages Eligible for Study:   12 Months to 10 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Age 12 months to < 11 years
  • Intermittent exotropia (manifest deviation) meeting all of the following criteria:

    • Intermittent exotropia at distance OR constant exotropia at distance and either intermittent exotropia or exophoria at near
    • Exodeviation at least 15PD at distance OR near measured by prism and alternate cover test (PACT)
    • Exodeviation at least 10PD at distance measured by PACT
  • No previous surgical or non-surgical treatment for IXT (other than refractive correction)
  • Visual acuity in the worse eye at least 0.3 logMAR (20/40 on ATS HOTV or 70 letters on E-ETDRS) for children ≥ 3 years of age
  • No interocular difference of visual acuity more than 0.2 logMAR (2 lines on ATS HOTV or 10 letters on E-ETDRS) for children ≥ 3 years of age
  • No hyperopia greater than +3.50 D spherical equivalent in either eye
  • No myopia greater than -6.00 D spherical equivalent in either eye
  • No prior strabismus, intraocular, or refractive surgery
  • No abnormality of the cornea, lens, or central retina
  • Investigator willing to observe the IXT untreated for 3 years unless specific criteria for deterioration are met

Exclusion Criteria:

  • Pure phoria at both distance and near
  • Prior non-surgical treatment for IXT other than refractive correction (e.g., vergence therapy, occlusion, vision therapy/orthoptics, or deliberate over-minus with spectacles more than 0.50D)
  • Previous amblyopia treatment other than refractive correction within 1 year
  • Vision therapy/orthoptics for any reason within the last year
  • Interocular visual acuity difference more than 0.2 logMAR (2 lines on ATS HOTV for patients 3 to < 7 years old or 10 letters on E-ETDRS for patients ≥ 7 years old) (patients ≥ 3 years only) and/or investigator plans to initiate amblyopia treatment at this time.
  • Limitation of ocular rotations due to restrictive or paretic strabismus
  • Craniofacial malformations affecting the orbits
  • Ocular disorders which would reduce visual acuity (except refractive error)
  • Prior strabismus surgery or botulinum injection, intraocular surgery, or refractive surgery
  • Strabismus surgery planned
  • Known skin reactions to patch or bandage adhesives
  • Significant neurological impairment such as cerebral palsy. Patients with mild speech delays or common reading and/or learning disabilities are not excluded.
  • Investigator planning to change refractive correction at this time (if the patient is otherwise eligible, the investigator should consider prescribing refractive correction and bringing the patient back at a later time for enrollment)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01032330


Locations
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United States, California
Southern California College of Optometry
Fullerton, California, United States, 92831-1699
United States, Minnesota
Mayo Clinic Department of Ophthalmology
Rochester, Minnesota, United States, 55905
Sponsors and Collaborators
Jaeb Center for Health Research
Pediatric Eye Disease Investigator Group
National Eye Institute (NEI)
Investigators
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Study Chair: Susan A Cotter, O.D., M.S. Southern California College of Optometry, Fullerton, CA
Study Chair: Brian G Mohney, M.D. Department of Ophthalmology, Mayo Clinic, Rochester, MN
Additional Information:
Publications of Results:
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Responsible Party: Jaeb Center for Health Research
ClinicalTrials.gov Identifier: NCT01032330    
Other Study ID Numbers: NEI-146
2U10EY011751 ( U.S. NIH Grant/Contract )
First Posted: December 15, 2009    Key Record Dates
Results First Posted: May 8, 2019
Last Update Posted: May 19, 2020
Last Verified: May 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Yes
Plan Description: In accordance with the NIH data sharing policy, a de-identified database is placed in the public domain on the PEDIG public website after the completion of each protocol and publication of the primary manuscript.
Time Frame: The data from the 6-month study is entered. The data for the 3-year study will be made available in 2020.
Access Criteria: Users will need a valid email address
URL: https://public.jaeb.org/pedig/stdy/153
Keywords provided by Jaeb Center for Health Research:
intermittent exotropia
IXT
natural history
occlusion therapy
occlusion
patching
strabismus
strabismus treatment
stereoacuity
motor alignment
Additional relevant MeSH terms:
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Exotropia
Strabismus
Ocular Motility Disorders
Cranial Nerve Diseases
Nervous System Diseases
Eye Diseases