Working…
COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC: https://www.coronavirus.gov.

Get the latest research information from NIH: https://www.nih.gov/coronavirus.
ClinicalTrials.gov
ClinicalTrials.gov Menu

Bilateral Lateral Rectus Recession Versus Unilateral Recess-Resect for Intermittent Exotropia (IXT1)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT01032603
Recruitment Status : Active, not recruiting
First Posted : December 15, 2009
Results First Posted : May 7, 2019
Last Update Posted : November 24, 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 purpose of this study is to evaluate the effectiveness of bilateral lateral rectus muscle recession versus unilateral lateral rectus recession with medial rectus resection procedures for the treatment of basic type and pseudo divergence excess type intermittent exotropia.

Condition or disease Intervention/treatment Phase
Exotropia Procedure: Bilateral lateral rectus recession (BLRc) Procedure: Unilateral lateral rectus recession with medial rectus resection (R&R) Not Applicable

Show Show detailed description

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 197 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Randomized Trial of Bilateral Lateral Rectus Recession Versus Unilateral Lateral Rectus Recession With Medial Rectus Resection for Intermittent Exotropia
Actual Study Start Date : June 1, 2010
Actual Primary Completion Date : February 9, 2017
Estimated Study Completion Date : February 28, 2022

Arm Intervention/treatment
Active Comparator: Bilateral lateral rectus recession
Bilateral lateral rectus recession surgery
Procedure: Bilateral lateral rectus recession (BLRc)
Bilateral lateral rectus recession surgery
Other Names:
  • BLR
  • BLRc

Active Comparator: Unilateral lateral rectus recession
Unilateral lateral rectus recession w/ medial rectus resection surgery
Procedure: Unilateral lateral rectus recession with medial rectus resection (R&R)
A unilateral lateral rectus recession combined with a medial rectus resection in the same eye. Choice of eye at investigator discretion based on any interocular difference, position under anesthesia, fixation preference, or forced duction testing. Reason for choice of eye will be recorded.
Other Name: R&R




Primary Outcome Measures :
  1. Number of Participants With Suboptimal Surgical Outcome as Assessed by Motor Alignment and Stereoacuity at Near by 3 Years [ Time Frame: 3 years ]

    A participant's intermittent exotropia (IXT) was considered to be a suboptimal surgical outcome if at any visit occurring 6 months or later, ANY of the following criteria are present by masked examiner testing:

    1. Exotropia at distance OR near at any time during the exam (i.e., can be constant or intermittent; determined by a cover/uncover test) with a magnitude of ≥10Δ by SPCT, confirmed by a retest
    2. Constant esotropia at distance OR near (determined by at least 3 cover/uncover tests-one must be before any dissociation) with a magnitude of ≥6Δ by SPCT, confirmed by a retest
    3. Decrease in Randot Preschool near stereoacuity ≥2 octaves (≥0.6 log arcsec) from enrollment, or to nil, confirmed by a retest Participants who underwent reoperation (or treatment with botulinum toxin) without first meeting any of the above suboptimal surgical outcome criteria were also counted as suboptimal surgical outcomes in the primary analysis.


Secondary Outcome Measures :
  1. Patients With Exotropia by 3 Years [ Time Frame: Enrollment to 3 years ]
    Exotropia ≥10Δ by simultaneous prism and cover test (SPCT) at distance or near, confirmed by a retest, by 3 years. Criteria was met before any reoperation, and regardless of whether suboptimal surgical outcome was met by another criteria.

  2. Patients With Constant Esotropia by 3 Years [ Time Frame: Enrollment to 3 years ]
    Constant esotropia ≥6Δ by simultaneous prism and cover test (SPCT) at distance or near, confirmed by a retest, by 3 years. Criteria was met before any reoperation, and regardless of whether suboptimal surgical outcome was met by another criteria.

  3. Number of Participants With Stereo Loss by 3 Years [ Time Frame: Enrollment to 3 years ]
    Decrease in Preschool Randot near stereoacuity ≥2 octaves (≥0.6 log arcsec) from enrollment, or to nil, confirmed by a retest, by 3 years. Criteria was met before any reoperation, and regardless of whether suboptimal surgical outcome was met by another criteria.

  4. Number of Participants With Exotropia Control at Distance at 3 Years [ Time Frame: 3 years after enrollment ]

    Exotropia control at distance was assessed in all patients who completed the 3-year visit. Numeric values for exotropia control were assigned so that the following seven 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

  5. Mean Distance Control at 3 Years [ Time Frame: 3 years after enrollment ]

    Mean exotropia control at distance was assessed in all patients who completed the 3-year visit. All 3-year visit data will be analyzed regardless of what treatment(s) a patient has received and regardless of whether the patient has undergone reoperation. Control at distance was analyzed as a continuous variable and compared between treatment groups using analysis of covariance (ANOVA) models that adjust for the corresponding baseline value (e.g. ANCOVA model of 3-year distance control will adjust for baseline distance control).

    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. Change in Distance Exotropia Control at 3 Years [ Time Frame: Enrollment to 3 years ]

    Change is defined as the baseline value minus the 3-year value, therefore positive change = improvement.

    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. Number of Participants With Exotropia Control at Near at 3 Years [ Time Frame: 3 years after enrollment ]

    Exotropia control at near was assessed in all patients who completed the 3-year visit.

    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. Mean Near Control at 3 Years [ Time Frame: 3 years after enrollment ]

    Mean exotropia control at near was assessed in all patients who completed the 3-year visit. All 3-year visit data will be analyzed regardless of what treatment(s) a patient has received and regardless of whether the patient has undergone reoperation. Control at near was analyzed as a continuous variable and compared between treatment groups using analysis of covariance (ANOVA) models that adjust for the corresponding baseline value (e.g. ANCOVA model of 3-year near control will adjust for baseline near control).

    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.


  9. Change in Near Exotropia Control at 3 Years [ Time Frame: Enrollment to 3 Years ]

    Change is defined as the baseline value minus the 3-year value, therefore positive change = improvement.

    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.


  10. Number of Participants With Distance PACT at 3 Years [ Time Frame: 3 years after enrollment ]

    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. PACT was assessed in all patients who completed the 3-year visit.

    ∆ = prism diopters; eso = esodeviation; exo = exodeviation


  11. Mean Distance PACT at 3 Years [ Time Frame: 3 years after enrollment ]
    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. Mean PACT was assessed in all patients who completed the 3-year visit. All 3-year visit data will be analyzed regardless of what treatment(s) a patient has received and regardless of whether the patient has undergone reoperation. PACT was analyzed as a continuous variable and compared between treatment groups using analysis of covariance (ANOVA) models that adjust for the corresponding baseline value (e.g. ANCOVA model of 3-year PACT at distance will adjust for baseline PACT at distance).

  12. Change in Distance PACT From Baseline to 3 Years [ Time Frame: Enrollment to 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. Change is defined as the baseline value minus the 3-year value, therefore positive change = improvement. If the 3-year PACT is an esodeviation, change in PACT from baseline is the reduction in the exodeviation plus the amount of the 3-year exodeviation.

  13. Number of Participants With Near PACT at 3 Years [ Time Frame: 3 years after enrollment ]

    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. PACT was assessed in all patients who completed the 3-year visit.

    ∆ = prism diopters; eso = esodeviation; exo = exodeviation


  14. Mean Near PACT at 3 Years [ Time Frame: 3 years after enrollment ]
    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. Mean PACT was assessed in all patients who completed the 3-year visit. All 3-year visit data will be analyzed regardless of what treatment(s) a patient has received and regardless of whether the patient has undergone reoperation. PACT was analyzed as a continuous variable and compared between treatment groups using analysis of covariance (ANOVA) models that adjust for the corresponding baseline value (e.g. ANCOVA model of 3-year PACT at near will adjust for baseline PACT at near).

  15. Change in Near PACT From Baseline to 3 Years [ Time Frame: Enrollment to 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. Change is defined as the baseline value minus the 3-year value, therefore positive change = improvement. If the 3-year PACT is an esodeviation, change in PACT from baseline is the reduction in the exodeviation plus the amount of the 3-year exodeviation.

  16. Participants With Near Stereoacuity Measures at 3 Years [ Time Frame: 3 years after enrollment ]

    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.

    Stereoacuity Testing: stereoacuity was assessed in current refractive correction using the following:

    Preschool Randot stereotest at near (performed at 40 cm): If stereoacuity is worse than 40 arcsec, it must be retested and the better of the 2 measurements will be used for eligibility.

    Distance Randot stereotest (performed at 3 meters)


  17. Mean Near Stereoacuity at 3 Years [ Time Frame: 3 years after enrollment ]

    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 seconds of arc, or arcsec).

    Stereoacuity Testing: stereoacuity was assessed in current refractive correction using the following:

    Preschool Randot stereotest at near (performed at 40 cm): If stereoacuity is worse than 40 arcsec, it must be retested and the better of the 2 measurements will be used for eligibility.

    Distance Randot stereotest (performed at 3 meters)


  18. Change in Near Stereoacuity From Baseline to 3 Years [ Time Frame: Enrollment to 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 seconds of arc, or arcsec).

    Change is defined as the baseline value minus the 3-year value, therefore positive change = improvement.


  19. Participants Distance Stereoacuity at 3 Years [ Time Frame: 3 years after enrollment ]

    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.

    Stereoacuity Testing: stereoacuity was assessed in current refractive correction using the following:

    Preschool Randot stereotest at near (performed at 40 cm): If stereoacuity is worse than 40 arcsec, it must be retested and the better of the 2 measurements will be used for eligibility.

    Distance Randot stereotest (performed at 3 meters)


  20. Mean Distance Stereoacuity at 3 Years [ Time Frame: 3 years after enrollment ]

    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 seconds of arc, or arcsec).

    Stereoacuity Testing: stereoacuity was assessed in current refractive correction using the following:

    Preschool Randot stereotest at near (performed at 40 cm): If stereoacuity is worse than 40 arcsec, it must be retested and the better of the 2 measurements will be used for eligibility.

    Distance Randot stereotest (performed at 3 meters)


  21. Change in Distance Stereoacuity From Baseline to 3 Years [ Time Frame: Enrollment to 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 seconds of arc, or arcsec).

    Change is defined as the baseline value minus the 3-year value, therefore positive change = improvement.


  22. Health Related Quality of Life [ Time Frame: 3 years after enrollment ]

    Health-related quality of life will be assessed using the Intermittent Exotropia Questionnaire (IXTQ). This questionnaire consists of 6 components:

    1. Child questionnaire - consists of 12 items which assess how the child feels about his/her eye condition.

      • One version for children aged 5 to < 8 years has a 3-level response scale
      • The version for children aged 8 years and older has a 5-level response scale
    2. Parent proxy questionnaire - consists of 12 items which assess how the parent feels the child's eye condition affects the child
    3. Parental questionnaire - consists of 17 items which assess how the child's eye condition affects the parent. Has 3 sub-scales: surgical, functional, and psycho-social.

    All scales ranged from 0 to 100; higher values indicated a better quality of life. Sub-scales were not combined, but rather were each evaluated individually on a scale of 0-100.


  23. Cumulative Number of Patients With Reoperation by 3 Years [ Time Frame: 3 years after enrollment ]

    The cumulative proportion of re-operation by 3 years was compared between treatment groups using methods similar to the primary analysis (i.e. using Kaplan-Meier method). A treatment-group difference and a corresponding 95% confidence interval were also calculated. Reasons for re-operation included:

    XT; XT and worsening stereo ; XT, worsening stereo and social concerns ; XT, diplopia, and headaches ; XT and squinting with one eye closed ; ET ; ET, worsening stereo, and diplopia; ET, worsening stereo and social concerns ; ET, worsening stereo, social concerns, and amblyopia ; Inferior oblique overaction


  24. Number of Participants With Complete or Near-Complete Resolution at 3 Years [ Time Frame: 3 years after enrollment ]
    Complete or near-complete resolution was defined as meeting all of the following at the 3 year visit: 1) exodeviation <10 Δ (tropia or phoria) by both SPCT and PACT at distance and near and ≥10 Δ reduction in PACT magnitude from the largest of the distance and near angles at enrollment, 2) esotropia <6 Δ at distance and near by SPCT, 3) no decrease in Randot Preschool stereoacuity of ≥2 octaves from the enrollment stereoacuity or to nil, 4) no reoperation or treatment with botulinum toxin, and 5) no non-surgical treatment for a recurrent or residual exodeviation.

  25. Participants Suboptimal Surgical Outcome at 3 Years [ Time Frame: 3 years after enrollment ]

    Suboptimal surgical outcome at the 3-year visit was defined as meeting any of the three suboptimal surgical outcome criteria at the 3-year visit (regardless of whether the criterion had been met at an earlier visit), or undergoing reoperation at any time.

    The three criteria for suboptimal surgical outcome were:

    1. Exotropia at distance OR near at any time during the exam (i.e., can be constant or intermittent; determined by a cover/uncover test) with a magnitude of ≥10Δ by SPCT, confirmed by a retest
    2. Constant esotropia at distance OR near (determined by at least 3 cover/uncover tests-one must be before any dissociation) with a magnitude of ≥6Δ by SPCT, confirmed by a retest
    3. Decrease in Randot Preschool near stereoacuity ≥2 octaves (≥0.6 log arcsec) from enrollment, or to nil, confirmed by a retest



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.


Layout table for eligibility information
Ages Eligible for Study:   3 Years to 10 Years   (Child)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Age 3 to < 11 years
  • Intermittent exotropia (manifest deviation) meeting all of the following:

    • Intermittent exotropia at distance OR constant exotropia at distance and either intermittent exotropia or exophoria at near
    • Largest exodeviation at either distance, near OR remote distance between 15 and 50 prism diopters (PD) (inclusive) by prism and alternate cover test (PACT)
    • Exodeviation at least 15 PD at distance and near by PACT
    • Basic type or pseudo divergence excess type
  • Stereoacuity of 400 arcsec or better at near by Preschool Randot stereotest (better of 2 measures)
  • Visual acuity in the worse eye at least 0.3 logMAR (20/40 on ATS HOTV or 70 letters on E-ETDRS)
  • No interocular difference of visual acuity more than 0.2 logMAR (2 lines on ATS HOTV or 10 letters on E-ETDRS testing)
  • Absence of high AC/A ratio (exclude > 6:1)
  • No previous intraocular surgery, strabismus surgery, or botulinum toxin treatment
  • Investigator planning to perform surgery for correction of IXT
  • No hyperopia greater than +3.50 D spherical equivalent (SE) in either eye

Exclusion Criteria:

  • Coexisting vertical deviation, oblique muscle dysfunction, dissociated vertical deviation (DVD), or A or V pattern, any of which the investigator plans to address with vertical transposition of horizontal rectus muscles, oblique surgery, or vertical rectus muscle surgery, i.e., only small vertical deviations, oblique muscle dysfunction, DVD, and A or V patterns not requiring surgery are allowed
  • Limitation of ocular rotations due to restrictive or paretic strabismus
  • Craniofacial malformations affecting the orbits
  • Interocular visual acuity difference of 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) and/or investigator plans to initiate amblyopia treatment at this time.
  • High AC/A ratio (exclude > 6:1 by gradient method)
  • Prior strabismus surgery or botulinum toxin injection
  • Ocular disorders that would reduce visual acuity (except refractive error)
  • Prior intraocular or refractive surgery
  • Significant neurological impairment such as cerebral palsy. Patients with mild speech and/or learning disabilities are eligible.
  • 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): NCT01032603


Locations
Layout table for location information
United States, Tennessee
Vanderbilt Children's Hospital
Nashville, Tennessee, United States, 37232-8808
Sponsors and Collaborators
Jaeb Center for Health Research
Pediatric Eye Disease Investigator Group
National Eye Institute (NEI)
Investigators
Layout table for investigator information
Study Chair: Sean P Donahue, M.D., Ph.D. Pediatric Ophthalmology Service, Vanderbilt Children's Hospital, Nashville, TN
  Study Documents (Full-Text)

Documents provided by Jaeb Center for Health Research:
Study Protocol  [PDF] June 21, 2017
Informed Consent Form  [PDF] July 23, 2013
Statistical Analysis Plan  [PDF] March 1, 2017

Additional Information:
Publications of Results:
Layout table for additonal information
Responsible Party: Jaeb Center for Health Research
ClinicalTrials.gov Identifier: NCT01032603    
Other Study ID Numbers: NEI-145
2U10EY011751 ( U.S. NIH Grant/Contract )
First Posted: December 15, 2009    Key Record Dates
Results First Posted: May 7, 2019
Last Update Posted: November 24, 2020
Last Verified: November 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: Data will be made available after publication of each primary manuscript.
Access Criteria: Users accessing the data must enter an email address.
Keywords provided by Jaeb Center for Health Research:
IXT
Exotropia
Strabismus
Intermittent exotropia
Additional relevant MeSH terms:
Layout table for MeSH terms
Exotropia
Strabismus
Ocular Motility Disorders
Cranial Nerve Diseases
Nervous System Diseases
Eye Diseases