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.
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
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
58
2.50D overminus spectacles
spectacles without overminus or no spectacles
Marshall B. Ketchum University
Fullerton, California, United States
Mayo Clinic
Rochester, Minnesota, United States
Mean Distance Exotropia Control Score
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.
Time frame: 8 weeks
Mean Near Exotropia Control Score
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.
Time frame: 8 weeks
Distribution of Distance Control Score at 8-week Outcome
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.
Time frame: 8 weeks
Distribution of Near Control Score at 8-week Outcome
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.
Time frame: 8 weeks
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Proportion of Subjects With Distance Control Treatment Response
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.
Time frame: 8 weeks
Symptom Survey Response to Question: Has Child Looked Over His/Her Spectacles Since Enrollment?
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.
Time frame: 8 weeks
Stereoacuity
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.
Time frame: 8 weeks
Distance Visual Acuity
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
Time frame: 8 weeks
Binocular Near Visual Acuity
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.
Time frame: 8 weeks
Symptom Survey Response to Question: Has Your Child Had Eyestrain (Tired, Sore, or Uncomfortable Eyes)?
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.
Time frame: 8 weeks
Symptom Survey Response to Question: Since Enrollment Has Your Child Avoided Reading or Doing Things up Close?
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.
Time frame: 8 weeks
Symptom Survey Response to Question: Has Your Child Reported Blurry Vision?
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.
Time frame: 8 weeks
Proportion of Subjects With Near Control Treatment Response
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.
Time frame: 8 weeks