Clinical Trial: Trial of Overminus Spectacle Therapy for Intermittent Exotropia

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

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

Brief Summary:

The main objectives of this randomized trial comparing overminus lens treatment to non-overminus (spectacles without overminus or spectacles with plano lenses) are to determine:

• The long-term on-treatment effect of overminus treatment on distance intermittent exotropia (IXT) control score.
• The off-treatment effect of overminus treatment on distance IXT control score (following weaning and 3 months off treatment).

Detailed Summary:

The main objectives of this randomized trial comparing overminus lens treatment to non-overminus (spectacles without overminus or spectacles with plano lenses) are to determine:

• The long-term on-treatment effect of overminus treatment on distance IXT control score.
• The off-treatment effect of overminus treatment on distance IXT control score (following weaning and 3 months off treatment).

The recently completed IXT3 pilot study (NCT02223650) addressed the question of whether overminus lens therapy has an initial short-term therapeutic effect for IXT while wearing overminus spectacles. There have been no rigorous studies that address the following important questions related to overminus lens therapy:

• Does overminus lens therapy have a long-term therapeutic effect for IXT while wearing overminus spectacles (over many months or years)?
• Does overminus lens therapy have a long-term therapeutic effect for IXT when overminus spectacles are discontinued?

Sponsor: Jaeb Center for Health Research

Current Primary Outcome:

• Mean Distance Control at 12-Months (On-Treatment Visit) [ Time Frame: 12 months ]
  A comparison of mean control of the distance exodeviation (average of 3 measurements over the exam) between the 2.50 diopters (D) overminus group and the non-overminus group (spectacles without overminus or no spectacles) at 12 months.
• Mean Distance Control at 18-Months (Off-Treatment Visit) [ Time Frame: 18 months ]
  A comparison of mean control of the distance exodeviation (average of 3 measurements over the exam) between the 2.50D overminus group and the non-overminus group (spectacles without overminus or no spectacles) at 18 months (after treatment discontinuation).

Original Primary Outcome:

• Mean Distance Control at 12-Months (On-Treatment Visit) [ Time Frame: 12 months ]
  A comparison of mean control of the distance exodeviation (average of 3 measurements over the exam) between the 2.50D overminus group and the non-overminus group (spectacles without overminus or no spectacles) at 12 months.
• Mean Distance Control at 18-Months (Off-Treatment Visit) [ Time Frame: 18 months ]
  A comparison of mean control of the distance exodeviation (average of 3 measurements over the exam) between the 2.50D overminus group and the non-overminus group (spectacles without overminus or no spectacles) at 18 months (after treatment discontinuation).

Current Secondary Outcome:

• No Spontaneous Tropia [ Time Frame: At 12 months and 18 months ]
  The proportion of subjects with no spontaneous tropia at 12 months and at 18 months will be compared between treatment groups.
• Change in Distance Control [ Time Frame: At 12 months and 18 months ]
  The proportion of subjects with ≥1 point improvement in distance control between baseline and 12 months and between baseline and 18 months will be compared between treatment groups. The proportion of subjects with ≥2 points improvement in distance control will be similarly compared between treatment groups.
• Deterioration as assessed by motor alignment and stereoacuity at near [ Time Frame: At 12 months and 18 months ]
  The cumulative proportion of subjects who meet deterioration criteria by the time point will be estimated for each treatment group.
• Near Control [ Time Frame: At 12 months and 18 months ]
  A comparison of mean control of the near exodeviation (average of 3 measurements over the exam) between the 2.50D overminus group and the non-overminus group (spectacles without overminus or no spectacles) at each timepoint.
• Change in Near Control [ Time Frame: At 12 months and 18 months ]
  For each timepoint, the proportion of subjects with ≥1 point improvement in near control since baseline will be compared between treatment groups. The proportion of subjects with ≥2 points improvement in near control will be similarly compared.
• Angle magnitude [ Time Frame: At 12 months and 18 months ]
  The magnitude of the deviation by Prism Alternate Cover Test (PACT) will be compared between treatment groups.
• Stereoacuity [ Time Frame: At 12 months and 18 months ]
  A comparison of near stereoacuity will be assessed using the Randot Preschool stereotest at near (performed at 40 cm) between treatment groups.
• Compliance with Spectacle Wear [ Time Frame: At 6 months and 12 months ]
  Compliance with spectacle wear will be assessed at the 6-month and 12-month outcome exam. Parents will give an estimate of the proportion of the time their children wore their spectacles. Proportion of time worn will be described as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), or poor (≤ 25%). The distribution of compliance will be assessed for each treatment group at the outcome exam.
• Symptom survey [ Time Frame: At 12 months and 18 months ]
  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.

Original Secondary Outcome:

• No Spontaneous Tropia at 12 Months [ Time Frame: 12 months ]
  The proportion of subjects with no spontaneous tropia at 12 months will be compared between treatment groups.
• Change in Distance Control at 12 Months [ Time Frame: 12 months ]
  The proportion of subjects with ≥1 point improvement in distance control between baseline and 12 months will be compared between treatment groups.
• No Spontaneous Tropia at 18 Months [ Time Frame: 18 Months ]
  The proportion of subjects with no spontaneous tropia at 18 months will be compared between treatment groups.
• Change in Distance Control at 18 Months [ Time Frame: 18 Months ]
  The proportion of subjects with ≥1 point improvement in distance control between baseline and 18 months will be compared between treatment groups.
• Deterioration [ Time Frame: At 12 months and 18 months ]
  The cumulative proportion of subjects who meet deterioration criteria by the time point will be estimated for each treatment group.
• Near Control [ Time Frame: At 12 months and 18 months ]
  Near control will be evaluated similarly to the change in distance control outcomes.
• Angle magnitude [ Time Frame: At 12 months and 18 months ]
  The magnitude of the deviation by Prism Alternate Cover Test (PACT) will be compared between treatment groups.
• Stereoacuity [ Time Frame: At 12 months and 18 months ]
  A comparison of near stereoacuity will be assessed with habitual correction using the Randot Preschool stereotest at near (performed at 40 cm) between treatment groups.
• Compliance with Spectacle Wear [ Time Frame: At 6 months and 12 months ]
  Compliance with spectacle wear will be assessed at the 6-month and 12-month outcome exam. Parents will give an estimate of the proportion of the time their children wore their spectacles. Proportion of time worn will be described as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), or poor (≤ 25%). The distribution of compliance will be assessed for each treatment group at the outcome exam.
• Symptom survey [ Time Frame: At 12 months and 18 months ]
  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.

Information By: Jaeb Center for Health Research

Dates:
Date Received: June 16, 2016
Date Started: January 16, 2017
Date Completion: May 2020
Last Updated: April 11, 2017
Last Verified: April 2017