Clinical Trial: A Pilot Clinical Trial of Overminus Spectacle Therapy for Intermittent Exotropia

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Pilot Randomized Clinical Trial of Overminus Spectacle Therapy for Intermittent Exotropia

Brief Summary: The objective of this short-term, pilot randomized trial comparing 2.50 diopters (D) overminus lens treatment vs. non-overminus (spectacles without overminus or no spectacles) in children with intermittent exotropia (IXT) 3 to <7 years of age is to determine whether to proceed to a full-scale, longer-term randomized trial.

Detailed Summary:

The objective of this short-term, pilot randomized trial comparing 2.50D overminus lens treatment vs. non-overminus (spectacles without overminus or no spectacles) is to determine whether to proceed to a full-scale, longer-term randomized trial. This decision will be based primarily on assessing the initial (8-week) response to overminus by comparing treatment groups on the following outcomes:

• Mean distance IXT control score (each patient's score is the mean of 3 control scores) (primary outcome)
• The proportion of subjects with treatment response, defined as 1 or more points improvement in mean of 3 distance IXT control scores (secondary outcome)
• Adverse effects, near visual acuity outcomes, and spectacle wear compliance

Current Primary Outcome: Mean Distance Exotropia Control Score [ Time Frame: 8 weeks ]

Original Primary Outcome:

• Mean distance control score [ Time Frame: 8 weeks ]
  A comparison of mean distance control scores (mean of the 3 assessments over the exam) between the 2.50D overminus group and the non-overminus group (spectacles without overminus or no spectacles) at 8 weeks.
• Near control score [ Time Frame: 8 weeks ]
  Control of exodeviation will be assessed in the habitual correction at distance (6 meters) and near (1/3 meter) using a standardized IXT control scale.

Current Secondary Outcome:

• Mean Near Exotropia Control Score [ Time Frame: 8 weeks ]
  At each visit, control of the exodeviation was measured at near (1/3 meters) using the Office Control Score which ranges from 0 (phoria, best control) to 5 (constant exotropia, worst control). Due to the variability of single measures of control, we used a "triple control score," which is a mean of 3 measures obtained at specific time-points during a 20- to 40-minute office examination. The secondary analysis was an intention-to-treat treatment group comparison of mean 8-week near control using an analysis of covariance (ANCOVA) model which adjusted for baseline near control.
• Distribution of Distance Control Score at 8-week Outcome [ Time Frame: 8 weeks ]
  Control of exodeviation will be assessed in the habitual correction at distance (6 meters) and near (1/3 meter) using a standardized IXT control scale.
• Distribution of Near Control Score at 8-week Outcome [ Time Frame: 8 weeks ]
  Control of exodeviation will be assessed in the habitual correction at distance (6 meters) and near (1/3 meter) using a standardized IXT control scale.
• Proportion of Subjects With Distance Control Treatment Response [ Time Frame: 8 weeks ]
  A comparison of the proportion of subjects showing a "treatment response," defined as an improvement of at least 1 point in distance control (mean of the 3 assessments over the exam) between enrollment and 8 weeks.
• Symptom Survey Response to Question: Has Child Looked Over His/Her Spectacles Since Enrollment? [ Time Frame: 8 weeks ]
  A brief survey of symptoms that may be associated with overminus such as headaches, eye strain, and problems with spectacle wear will be administered to the parents of the subjects. Parents are asked to respond to the survey questions based on their observations of their child in the past 2 weeks. Response options are based on frequency of observations; never, rarely, sometimes, often, always, and not applicable. Survey items were derived based on expert opinion of pediatric ophthalmologists and optometrists on the study planning committee. The response options were a 5-point Likert-type scale based on frequency of observations: never = score of 0, almost never = 1, sometimes = 2, often = 3, and always = 4.
• Stereoacuity [ Time Frame: 8 weeks ]
  Stereoacuity will be assessed with habitual correction using the Randot Preschool stereotest at near (performed at 40 cm). A specific level of stereoacuity is not required for eligibility.
• Distance Visual Acuity [ Time Frame: 8 weeks ]
  Monocular distance visual acuity testing with the habitual correction and without cycloplegia was measured using the Amblyopia Treatment Study HOTV testing protocol on any certified visual acuity system. The treatment groups were not different with respect to 8-week control PACT at distance
• Binocular Near Visual Acuity [ Time Frame: 8 weeks ]
  Binocular near visual acuity was tested in habitual correction using the ATS4 near visual acuity test. The treatment groups were not different with respect to 8-week control at near.
• Symptom Survey Response to Question: Has Your Child Had Eyestrain (Tired, Sore, or Uncomfortable Eyes)? [ Time Frame: 8 weeks ]
  A brief survey of symptoms that may be associated with overminus such as headaches, eye strain, and problems with spectacle wear will be administered to the parents of the subjects. Parents are asked to respond to the survey questions based on their observations of their child in the past 2 weeks. Response options are based on frequency of observations; never, rarely, sometimes, often, always, and not applicable. Survey items were derived based on expert opinion of pediatric ophthalmologists and optometrists on the study planning committee. The response options were a 5-point Likert-type scale based on frequency of observations: never = score of 0, almost never = 1, sometimes = 2, often = 3, and always = 4.
• Symptom Survey Response to Question: Since Enrollment Has Your Child Avoided Reading or Doing Things up Close? [ Time Frame: 8 weeks ]
  A brief survey of symptoms that may be associated with overminus such as headaches, eye strain, and problems with spectacle wear will be administered to the parents of the subjects. Parents are asked to respond to the survey questions based on their observations of their child in the past 2 weeks. Response options are based on frequency of observations; never, rarely, sometimes, often, always, and not applicable. Survey items were derived based on expert opinion of pediatric ophthalmologists and optometrists on the study planning committee. The response options were a 5-point Likert-type scale based on frequency of observations: never = score of 0, almost never = 1, sometimes = 2, often = 3, and always = 4.
• Symptom Survey Response to Question: Has Your Child Reported Blurry Vision? [ Time Frame: 8 weeks ]
  
  

  Original Secondary Outcome:

  • Proportion of subjects with treatment response [ Time Frame: 8 weeks ]
    A comparison of the proportion of subjects showing a "treatment response," defined as an improvement of at least 1 point in distance control (mean of the 3 assessments over the exam) between enrollment and 8 weeks.
  • Symptom survey [ Time Frame: 8 weeks ]
    A brief survey of symptoms that may be associated with overminus such as headaches, eye strain, and problems with spectacle wear will be administered to the parents of the subjects. Parents are asked to respond to the survey questions based on their observations of their child in the past 2 weeks. Response options are based on frequency of observations; never, rarely, sometimes, often, always, and not applicable.
  • Stereoacuity [ Time Frame: 8 weeks ]
    Stereoacuity will be assessed with habitual correction using the Randot Preschool stereotest at near (performed at 40 cm). A specific level of stereoacuity is not required for eligibility.
  • Distance Visual Acuity [ Time Frame: 8 weeks ]
    Monocular distance visual acuity testing with the habitual correction and without cycloplegia will be measured using the Amblyopia Treatment Study HOTV testing protocol on any certified visual acuity system.
  • Binocular Near Visual Acuity [ Time Frame: 8 weeks ]
    Binocular near visual acuity will be tested in habitual correction using the ATS4 near visual acuity test.

  
  
  Information By: Jaeb Center for Health Research
  

  Dates:
  Date Received: August 20, 2014
  Date Started: December 2014
  Date Completion:
  Last Updated: April 11, 2017
  Last Verified: April 2017
  

  

  Join Millions

  Sign Up For One Of Our
  Newsletters

  Email

  Sign Up