A Pilot Clinical Trial of Overminus Spectacle Therapy for Intermittent Exotropia

Not Applicable

Completed

Conditions: Intermittent Exotropia

Interventions: Device: Overminus treatment
Device: Non-overminus treatment

Registration Number: NCT02223650

Lead Sponsor: Jaeb Center for Health Research

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 Description: 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

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 58

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Overminus Treatment	Overminus treatment	2.50D overminus spectacles
Non-overminus Treatment	Non-overminus treatment	spectacles without overminus or no spectacles

Primary Outcome Measures

Name	Time	Method
Mean Distance Exotropia Control Score	8 weeks	At each visit, control of the exodeviation was measured at distance (6 meters) and 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 primary analysis was an intention-to-treat treatment group comparison of mean 8-week distance control using an analysis of covariance (ANCOVA) model which adjusted for baseline distance control. \*Mohney BG, Holmes JM. An office-based scale for assessing control in intermittent exotropia. Strabismus 2006;14(3):147-50.

Secondary Outcome Measures

Name	Time	Method
Distance Visual Acuity	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
Distribution of Near Control Score at 8-week Outcome	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.
Symptom Survey Response to Question: Has Your Child Reported Blurry Vision?	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.
Mean Near Exotropia Control Score	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.
Proportion of Subjects With Distance Control Treatment Response	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.
Stereoacuity	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.
Symptom Survey Response to Question: Has Your Child Had Eyestrain (Tired, Sore, or Uncomfortable Eyes)?	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.
Distribution of Distance Control Score at 8-week Outcome	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.
Symptom Survey Response to Question: Has Child Looked Over His/Her Spectacles Since Enrollment?	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.
Binocular Near Visual Acuity	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: Since Enrollment Has Your Child Avoided Reading or Doing Things up Close?	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.
Proportion of Subjects With Near Control Treatment Response	8 weeks	A comparison of the proportion of subjects showing a "treatment response," defined as an improvement of at least 1 point in near control (mean of the 3 assessments over the exam) between enrollment and 8 weeks.