Exotropia Intermittent
Conditions
Keywords
Prism
Brief summary
The objective of this short-term, pilot randomized trial comparing spectacles with relieving prism to spectacles without prism 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 prism by comparing treatment groups on the following outcomes: * Mean distance intermittent exotropia (IXT) control score (the mean of 3 control scores) (primary outcome) * The proportion of participants demonstrating a treatment response, defined as ≥1 point improvement in the mean distance IXT control score without spontaneous exotropia during control testing (secondary outcome) * The proportion of participants reporting adverse effects and good/excellent spectacle wear compliance
Interventions
DEVICEPrism Glasses
Spectacles with refractive correction and base-in relieving prism (40% of the greater of the exodeviation by PACT at distance or near) equally divided between the 2 lenses
DEVICENon-Prism Glasses
Spectacles with refractive correction (or plano spectacles if no significant refractive error) and no prism
Sponsors
Pediatric Eye Disease Investigator Group
National Eye Institute (NEI)
Jaeb Center for Health Research
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
At the 8-week outcome visit, a Masked Examiner, who is a pediatric ophthalmologist, pediatric optometrist, or certified orthoptist, will assess the control of the exodeviation and perform PACT testing. The Masked Examiner must be someone other than the investigator.
Eligibility
Sex/Gender
ALL
Age
3 Years to 13 Years
Healthy volunteers
No
Inclusion criteria
Intermittent Exotropia meeting all of the following criteria: * Age 3 to 13 years * Mean distance control score of ≥2.00 points with at least 1 measure of 3, 4, or 5 points (i.e, spontaneous tropia) from the 3 assessments during the exam * A near control score ≤4 on at least 1 of 3 assessments (cannot have score of 5, 5, 5) * Distance exodeviation between 16 Prism Diopters (Δ) and 35 Δ (inclusive) by PACT * Near exodeviation between 10 Δ and 35 Δ (inclusive) by PACT * Near deviation does not exceed distance deviation by more than 10 Δ by PACT (i.e., convergence insufficiency-type IXT excluded) * Refractive error between -6.00 Diopters (D) spherical equivalent (SE) and +2.50 D SE (inclusive) (based on a cycloplegic refraction performed within 7 months but prior to the day of enrollment) * Refractive correction (must be worn for at least 1 week if refractive error meets any of the following (based on a cycloplegic refraction performed within 7 months but prior to the day of enrollment): * SE anisometropia ≥1.00 D * Astigmatism ≥1.00 D in either eye * SE myopia ≥-0.50 D in either eye * If spectacles have been prescribed and are worn, they must meet the following pre- enrollment criteria: * SE anisometropia corrected to within 1.00 D of full SE anisometropic difference * Astigmatism corrected to within 1.00 D of full magnitude; axis within 10 degrees if astigmatism ≤1.00 D and axis within 5 degrees if astigmatism \>1.00 D
Exclusion criteria
* Dissociated vertical deviation (DVD) * Vertical deviation \>3 Δ in primary gaze at distance or near * Patterns (such as an A or V pattern) with a downgaze measurement of \>10 Δ difference from straight ahead by PACT, measured per investigator's routine method * Treatment for IXT or amblyopia (other than refractive correction) within the past 4 weeks, including vision therapy, orthoptics, patching, atropine, or other penalization * Substantial overminus spectacles (spectacles overminused by more than 1.00 D SE than the most recent cycloplegic refraction and also results in minus SE power in the spectacles; underplussing is allowed) within the past 4 weeks * Prior strabismus, intraocular, or refractive surgery (including BOTOX injection) * Previous use of prism spectacles Additional Eligibility Criteria for Randomization Based on Prism Adaptation Testing * Exodeviation by PACT while wearing trial relieving prism for 30 minutes is smaller at distance or near than measured during initial testing (e.g. not fully adapting to prism at both distances) * No new esotropia on cover test at near while wearing trial relieving prism for 30 minutes, compared with enrollment measurement taken without prism * No esodeviation \>6 Δ on PACT at near while wearing trial relieving prism for 30 minutes
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Exotropia Control Score at Distance, Continuous Score | 8 weeks | The primary analysis will be an intent-to-treat comparison of mean 8-week control of the distance exodeviation (average of 3 measurements) between treatment groups using an analysis of covariance (ANCOVA) model, which adjusts for baseline distance control. Distance control scores range from 0 to 5 with higher scores indicating a worse outcome. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Child Assessment of Symptoms - Do Your Eyes Feel Funny? | 8 Weeks | Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | 8 Weeks | Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | 8 Weeks | Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | 8 Weeks | Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | 8 Weeks | Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Exotropia Control Score at Distance, % With Treatment Response | 8 weeks | The secondary analysis will calculate the percentage of participants with a treatment response, defined as ≥1 point improvement in control of their distance exodeviation (average of 3 measurements) between baseline and the 8-week outcome exam. |
| Exotropia Control Score at Distance and Near, % With No Spontaneous Tropia | 8 Weeks | The proportion of participants with no spontaneous tropia at 8 weeks will be compared between treatment groups using a two-sided Barnard's test with alpha of 0.05, with calculation of a two-sided 95% confidence interval on the difference in proportions. No spontaneous tropia at the 8-week primary outcome exam is defined as a score of ≤2 (0, 1, or 2) on all three assessments of control at distance and at near. |
| Exotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks | 8 Weeks | Control of the exodeviation was measured at distance using the IXT Office Control Score, (Mohney, 2006) which ranges from 0 (phoria) to 5 (constant exotropia). Control levels 3-5 were assigned based on the duration of manifest exotropia during a 30-second period before any dissociation. If no exotropia was observed, control levels 0-2 were assigned based on the longest time to reestablishing fusion after 3 consecutive 10-second periods of dissociation. Control was measured at the beginning, middle, and end (3 tests) of a 20- to 40-minute office examination, and the mean was used. The change in distance control from baseline to 8 weeks will be calculated. A negative value indicates improvement. |
| Exotropia Control Score at Near, Continuous Score | 8 Weeks | Near control will be evaluated similarly to the primary outcome and outcome measures 2-4. Near control scores range from 0 to 5 with higher scores indicating a worse outcome. |
| Exodeviation by PACT at Distance, Continuous | 8 Weeks | The measure of ocular alignment at distance by PACT will be summarized at 8 weeks for each treatment group. A higher deviation is worse. |
| Exodeviation by PACT at Near, Continuous | 8 Weeks | The measure of ocular alignment at near by PACT will be summarized at 8 weeks for each treatment group. A higher deviation is worse. |
| Randot Preschool Stereoacuity at Near, Continuous | 8 Weeks | Randot® Preschool Stereoacuity test (Stereo Optical Co., Inc., Chicago, IL). For analysis, stereoacuity was converted from seconds of arc scores to log arcsec values (in parentheses) as follows: 40 (1.60), 60 (1.78), 100 (2.00), 200 (2.30), 400 (2.60), 800 (2.90); participants with no detectable (nil) stereoacuity were assigned the value of 1600 (3.20). The measure of Randot Preschool Stereoacuity at near will be summarized at 8 weeks for each treatment group. A lower score is better. |
| Compliance of Spectacle Wear | 8 weeks | Parents will be asked to complete a compliance calendar by recording the percentage of time their child has worn the study-prescribed spectacle correction each day. Proportion of time worn each day will be described as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), poor (1 to 25%), or none (0%). Based on review of the calendars and discussion with parents at the 8-week outcome exam, the investigator will record the total proportion of time worn as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), poor (1 to 25%), or none (0%: did not fill prescription or never picked up spectacles). The distribution of compliance will be assessed for each treatment group at the outcome exam. |
| Child Assessment of Symptoms - Do Your Eyes Hurt? | 8 Weeks | Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Child Assessment of Symptoms - Do You Have Double Vision? | 8 Weeks | Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Child Assessment of Symptoms - Is it Hard for You to Stare at Things? | 8 Weeks | Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun? | 8 Weeks | Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Child Assessment of Symptoms - Do Your Eyes go in and Out? | 8 Weeks | Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Child Assessment of Symptoms - Is it Hard to Focus Your Eyes? | 8 Weeks | Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | 8 Weeks | Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | 8 Weeks | Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
| Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | 8 Weeks | Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Suppression | 8 Weeks | The suppression assessment is a standardized method of assessing the depth of suppression experienced while the participant is tropic (NOT aligned). Scoring is reported on an ordinal scale from 0 (no suppression) to 3 (dense suppression). Missing refers to cases in which participants were unable to understand the test and/or gave unreliable responses. As an exploratory analysis, the distribution of suppression level (none, mild, moderate, severe, missing) will be tabulated after 8 weeks by treatment group. |
| Fusional Convergence - Continuous Recovery Point | 8 Weeks | As an exploratory analysis, the distribution of fusional convergence amplitude (break point, blur point, and recovery) at 8 weeks will be summarized for each treatment group. Fusional amplitudes are a measure of how well a participant can converge their eyes using fusional vergence. It is measured by increasing base-out prism to the point that the participant is no longer able to control the deviation. The total amount of fusion is the magnitude of the base-out prism the participant was able to overcome plus the magnitude of the deviation. A higher number of prism diopters for break point is better than a lower number. A lower number for recovery is better than a higher number. |
| Fusional Convergence - Continuous Break Point | 8 Weeks | As an exploratory analysis, the distribution of fusional convergence amplitude (break point, blur point, and recovery) at 8 weeks will be summarized for each treatment group. Fusional amplitudes are a measure of how well a participant can converge their eyes using fusional vergence. It is measured by increasing base-out prism to the point that the participant is no longer able to control the deviation. The total amount of fusion is the magnitude of the base-out prism the participant was able to overcome plus the magnitude of the deviation. A higher number of prism diopters for break point is better than a lower number. A lower number for recovery point is better than a higher number. |
| Distance Visual Acuity (Snellen Equivalent) | 8 Weeks | Distance visual acuity will be assessed at the 8-week outcome exam. Any optotype method can be used for testing. The distribution of distance visual acuity Snellen Equivalents will be tabulated for each treatment group. A lower Snellen Equivalent is best. |
Countries
United States
Participant flow
Recruitment details
Between 09/01/2019 and 07/30/2020, 61 participants were enrolled into the study across 28 clinical sites. After prism-adaptation testing to confirm eligibility, 4 participants did not meet eligibility criteria and 57 participants were randomized to receive either 40% base-in prism spectacles (n=28) or non-prism spectacles (n=29).
Pre-assignment details
After enrollment testing and prior to randomization, an in-office prism adaptation test was administered so that children with full prism adaptation (i.e., deviation magnitude increases by the amount of prism worn) would be excluded from the trial. Of 61 participants enrolled, 4 participants did not meet eligibility criteria after prism-adaptation testing and were dropped prior to randomization.
Participants by arm
| Arm | Count |
|---|---|
| Prism Group Spectacles with refractive correction and base-in relieving prism (40% of the greater of the exodeviation by prism and alternate cover test (PACT) at distance or near) equally divided between the 2 lenses will be prescribed to the participant
Prism Glasses: Spectacles with refractive correction and base-in relieving prism (40% of the greater of the exodeviation by PACT at distance or near) equally divided between the 2 lenses | 28 |
| Non-Prism Group Spectacles with refractive correction (or plano spectacles if no significant refractive error) and no prism will be prescribed to the participant
Non-Prism Glasses: Spectacles with refractive correction (or plano spectacles if no significant refractive error) and no prism | 29 |
| Total | 57 |
Baseline characteristics
| Characteristic | Prism Group | Total | Non-Prism Group |
|---|---|---|---|
| Age, Categorical <=18 years | 28 Participants | 57 Participants | 29 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Continuous | 6.4 years STANDARD_DEVIATION 2.4 | 6.6 years STANDARD_DEVIATION 2.2 | 6.8 years STANDARD_DEVIATION 2.1 |
| Age, Customized 3 to <5 years | 10 Participants | 17 Participants | 7 Participants |
| Age, Customized 5 to <7 years | 7 Participants | 17 Participants | 10 Participants |
| Age, Customized 7 to <9 years | 8 Participants | 16 Participants | 8 Participants |
| Age, Customized >=9 years | 3 Participants | 7 Participants | 4 Participants |
| Exodeviation by PACT at Distance, Categorical 10 to 15 pd | 0 Participants | 0 Participants | 0 Participants |
| Exodeviation by PACT at Distance, Categorical 16 to 18 pd | 3 Participants | 8 Participants | 5 Participants |
| Exodeviation by PACT at Distance, Categorical 1 to 9 pd | 0 Participants | 0 Participants | 0 Participants |
| Exodeviation by PACT at Distance, Categorical 20 to 25 pd | 18 Participants | 33 Participants | 15 Participants |
| Exodeviation by PACT at Distance, Categorical 30 to 35 pd | 7 Participants | 16 Participants | 9 Participants |
| Exodeviation by PACT at Distance, Categorical 40 to 45 pd | 0 Participants | 0 Participants | 0 Participants |
| Exodeviation by PACT at Distance, Continuous | 25.1 Prism Diopters (pd) STANDARD_DEVIATION 4.7 | 25.0 Prism Diopters (pd) STANDARD_DEVIATION 5.2 | 24.9 Prism Diopters (pd) STANDARD_DEVIATION 5.6 |
| Exodeviation by PACT at Near, Categorical 10 to 15 pd | 2 Participants | 8 Participants | 6 Participants |
| Exodeviation by PACT at Near, Categorical 16 to 18 pd | 8 Participants | 15 Participants | 7 Participants |
| Exodeviation by PACT at Near, Categorical 1 to 9 pd | 0 Participants | 0 Participants | 0 Participants |
| Exodeviation by PACT at Near, Categorical 20 to 25 pd | 15 Participants | 23 Participants | 8 Participants |
| Exodeviation by PACT at Near, Categorical 30 to 35 pd | 3 Participants | 11 Participants | 8 Participants |
| Exodeviation by PACT at Near, Categorical 40 to 45 pd | 0 Participants | 0 Participants | 0 Participants |
| Exodeviation by PACT at Near, Continuous | 21.5 Prism Diopters (pd) STANDARD_DEVIATION 5.1 | 21.3 Prism Diopters (pd) STANDARD_DEVIATION 6.4 | 21.1 Prism Diopters (pd) STANDARD_DEVIATION 7.5 |
| Exotropia Control Score at Distance, Categorical 0 to <1 unit | 0 Participants | 0 Participants | 0 Participants |
| Exotropia Control Score at Distance, Categorical 1 to <2 units | 0 Participants | 0 Participants | 0 Participants |
| Exotropia Control Score at Distance, Categorical 2 to <3 units | 8 Participants | 16 Participants | 8 Participants |
| Exotropia Control Score at Distance, Categorical 3 to <4 units | 10 Participants | 20 Participants | 10 Participants |
| Exotropia Control Score at Distance, Categorical 4 to 5 units | 10 Participants | 21 Participants | 11 Participants |
| Exotropia Control Score at Distance, Continuous | 3.4 units on a scale STANDARD_DEVIATION 0.9 | 3.5 units on a scale STANDARD_DEVIATION 0.9 | 3.5 units on a scale STANDARD_DEVIATION 0.9 |
| Exotropia Control Score at Near, Categorical 0 to 1 unit | 2 Participants | 8 Participants | 6 Participants |
| Exotropia Control Score at Near, Categorical 1 to <2 units | 9 Participants | 18 Participants | 9 Participants |
| Exotropia Control Score at Near, Categorical 2 to <3 units | 6 Participants | 15 Participants | 9 Participants |
| Exotropia Control Score at Near, Categorical 3 to <4 units | 6 Participants | 10 Participants | 4 Participants |
| Exotropia Control Score at Near, Categorical 4 to 5 units | 5 Participants | 6 Participants | 1 Participants |
| Exotropia Control Score at Near, Continuous | 2.3 units on a scale STANDARD_DEVIATION 1.3 | 2.0 units on a scale STANDARD_DEVIATION 1.2 | 1.7 units on a scale STANDARD_DEVIATION 1.1 |
| Race/Ethnicity, Customized Asian | 0 Participants | 3 Participants | 3 Participants |
| Race/Ethnicity, Customized Black/African American | 6 Participants | 8 Participants | 2 Participants |
| Race/Ethnicity, Customized Hispanic | 4 Participants | 11 Participants | 7 Participants |
| Race/Ethnicity, Customized More than one race | 2 Participants | 2 Participants | 0 Participants |
| Race/Ethnicity, Customized White | 16 Participants | 33 Participants | 17 Participants |
| Randot Preschool Stereoacuity at Near, Categorical 100 (2.00) | 9 Participants | 16 Participants | 7 Participants |
| Randot Preschool Stereoacuity at Near, Categorical 200 (2.30) | 3 Participants | 7 Participants | 4 Participants |
| Randot Preschool Stereoacuity at Near, Categorical 400 (2.60) | 5 Participants | 8 Participants | 3 Participants |
| Randot Preschool Stereoacuity at Near, Categorical 40 (1.60) | 2 Participants | 5 Participants | 3 Participants |
| Randot Preschool Stereoacuity at Near, Categorical 60 (1.78) | 6 Participants | 14 Participants | 8 Participants |
| Randot Preschool Stereoacuity at Near, Categorical 800 (2.90) | 2 Participants | 4 Participants | 2 Participants |
| Randot Preschool Stereoacuity at Near, Categorical Nil (3.10) | 1 Participants | 3 Participants | 2 Participants |
| Randot Preschool Stereoacuity at Near, Continuous | 2.3 log arcsec STANDARD_DEVIATION 0.4 | 2.3 log arcsec STANDARD_DEVIATION 0.4 | 2.3 log arcsec STANDARD_DEVIATION 0.5 |
| Refractive Error Average of Eyes, Categorical 0.00 to <1.00 diopters | 12 Participants | 28 Participants | 16 Participants |
| Refractive Error Average of Eyes, Categorical -1.00 to <-0.00 diopters | 4 Participants | 8 Participants | 4 Participants |
| Refractive Error Average of Eyes, Categorical 1.00 to <2.00 diopters | 9 Participants | 15 Participants | 6 Participants |
| Refractive Error Average of Eyes, Categorical -2.00 to <-1.00 diopters | 2 Participants | 2 Participants | 0 Participants |
| Refractive Error Average of Eyes, Categorical -6.00 to <-2.00 diopters | 1 Participants | 4 Participants | 3 Participants |
| Refractive Error Average of Eyes, Continuous | 0.3 Spherical Equivalent Diopters STANDARD_DEVIATION 1 | 0.2 Spherical Equivalent Diopters STANDARD_DEVIATION 1.2 | 0.1 Spherical Equivalent Diopters STANDARD_DEVIATION 1.4 |
| Region of Enrollment United States | 28 participants | 57 participants | 29 participants |
| Sex: Female, Male Female | 17 Participants | 33 Participants | 16 Participants |
| Sex: Female, Male Male | 11 Participants | 24 Participants | 13 Participants |
| Suppression Dense (3 suppression) | 18 Participants | 28 Participants | 10 Participants |
| Suppression Mild (1 suppression) | 1 Participants | 5 Participants | 4 Participants |
| Suppression Missing | 2 Participants | 6 Participants | 4 Participants |
| Suppression Moderate (2 suppression) | 4 Participants | 12 Participants | 8 Participants |
| Suppression None (0 suppression) | 3 Participants | 6 Participants | 3 Participants |
| Treatment for Intermittent Exotropia Prior to Enrollment None | 18 Participants | 37 Participants | 19 Participants |
| Treatment for Intermittent Exotropia Prior to Enrollment Overminus Lenses | 2 Participants | 5 Participants | 3 Participants |
| Treatment for Intermittent Exotropia Prior to Enrollment Patching | 7 Participants | 12 Participants | 5 Participants |
| Treatment for Intermittent Exotropia Prior to Enrollment Patching and Atropine | 0 Participants | 1 Participants | 1 Participants |
| Treatment for Intermittent Exotropia Prior to Enrollment Patching and Overminus Lenses | 1 Participants | 1 Participants | 0 Participants |
| Treatment for Intermittent Exotropia Prior to Enrollment Vision Therapy and Overminus Lenses | 0 Participants | 1 Participants | 1 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 28 | 0 / 29 |
| other Total, other adverse events | 0 / 28 | 0 / 29 |
| serious Total, serious adverse events | 0 / 28 | 0 / 29 |
Outcome results
Primary
Exotropia Control Score at Distance, Continuous Score
The primary analysis will be an intent-to-treat comparison of mean 8-week control of the distance exodeviation (average of 3 measurements) between treatment groups using an analysis of covariance (ANCOVA) model, which adjusts for baseline distance control. Distance control scores range from 0 to 5 with higher scores indicating a worse outcome.
Time frame: 8 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prism Group | Exotropia Control Score at Distance, Continuous Score | 3.6 units on a scale | Standard Deviation 1.3 |
| Non-Prism Group | Exotropia Control Score at Distance, Continuous Score | 3.3 units on a scale | Standard Deviation 1.5 |
Comparison: The primary analysis was the treatment group difference (and 95% CI) in mean distance control at the 8-week outcome visit using an ANCOVA adjusted for baseline distance control. The planned convenience sample size of 64 was expected to provide outcome data for at least 60 participants (30 per group).95% CI: [-0.5, 1.1]
Secondary
Child Assessment of Symptoms - Do You Have Double Vision?
Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Child Assessment of Symptoms - Do You Have Double Vision? | Never | 17 Participants |
| Prism Group | Child Assessment of Symptoms - Do You Have Double Vision? | Sometimes | 8 Participants |
| Prism Group | Child Assessment of Symptoms - Do You Have Double Vision? | Almost Always | 0 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do You Have Double Vision? | Never | 17 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do You Have Double Vision? | Sometimes | 7 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do You Have Double Vision? | Almost Always | 1 Participants |
Secondary
Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun?
Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun? | Never | 11 Participants |
| Prism Group | Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun? | Sometimes | 8 Participants |
| Prism Group | Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun? | Almost Always | 6 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun? | Never | 14 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun? | Sometimes | 5 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun? | Almost Always | 6 Participants |
Secondary
Child Assessment of Symptoms - Do Your Eyes Feel Funny?
Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Child Assessment of Symptoms - Do Your Eyes Feel Funny? | Never | 17 Participants |
| Prism Group | Child Assessment of Symptoms - Do Your Eyes Feel Funny? | Sometimes | 7 Participants |
| Prism Group | Child Assessment of Symptoms - Do Your Eyes Feel Funny? | Almost Always | 1 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes Feel Funny? | Never | 20 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes Feel Funny? | Sometimes | 3 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes Feel Funny? | Almost Always | 2 Participants |
Secondary
Child Assessment of Symptoms - Do Your Eyes go in and Out?
Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Child Assessment of Symptoms - Do Your Eyes go in and Out? | Never | 20 Participants |
| Prism Group | Child Assessment of Symptoms - Do Your Eyes go in and Out? | Sometimes | 2 Participants |
| Prism Group | Child Assessment of Symptoms - Do Your Eyes go in and Out? | Almost Always | 3 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes go in and Out? | Never | 19 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes go in and Out? | Sometimes | 3 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes go in and Out? | Almost Always | 3 Participants |
Secondary
Child Assessment of Symptoms - Do Your Eyes Hurt?
Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Child Assessment of Symptoms - Do Your Eyes Hurt? | Never | 15 Participants |
| Prism Group | Child Assessment of Symptoms - Do Your Eyes Hurt? | Sometimes | 6 Participants |
| Prism Group | Child Assessment of Symptoms - Do Your Eyes Hurt? | Almost Always | 4 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes Hurt? | Never | 22 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes Hurt? | Sometimes | 3 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Do Your Eyes Hurt? | Almost Always | 0 Participants |
Secondary
Child Assessment of Symptoms - Is it Hard for You to Stare at Things?
Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Child Assessment of Symptoms - Is it Hard for You to Stare at Things? | Never | 16 Participants |
| Prism Group | Child Assessment of Symptoms - Is it Hard for You to Stare at Things? | Sometimes | 7 Participants |
| Prism Group | Child Assessment of Symptoms - Is it Hard for You to Stare at Things? | Almost Always | 2 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Is it Hard for You to Stare at Things? | Never | 15 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Is it Hard for You to Stare at Things? | Sometimes | 8 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Is it Hard for You to Stare at Things? | Almost Always | 2 Participants |
Secondary
Child Assessment of Symptoms - Is it Hard to Focus Your Eyes?
Adverse symptoms of intermittent exotropia will be summarized at the 8-week outcome exam using a symptom survey that is administered to the child. Response options are based on frequency of observations: never, sometimes, and always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Child Assessment of Symptoms - Is it Hard to Focus Your Eyes? | Never | 16 Participants |
| Prism Group | Child Assessment of Symptoms - Is it Hard to Focus Your Eyes? | Sometimes | 5 Participants |
| Prism Group | Child Assessment of Symptoms - Is it Hard to Focus Your Eyes? | Almost Always | 4 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Is it Hard to Focus Your Eyes? | Never | 12 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Is it Hard to Focus Your Eyes? | Sometimes | 11 Participants |
| Non-Prism Group | Child Assessment of Symptoms - Is it Hard to Focus Your Eyes? | Almost Always | 2 Participants |
Secondary
Compliance of Spectacle Wear
Parents will be asked to complete a compliance calendar by recording the percentage of time their child has worn the study-prescribed spectacle correction each day. Proportion of time worn each day will be described as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), poor (1 to 25%), or none (0%). Based on review of the calendars and discussion with parents at the 8-week outcome exam, the investigator will record the total proportion of time worn as excellent (76% to 100%), good (51% to 75%), fair (26% to 50%), poor (1 to 25%), or none (0%: did not fill prescription or never picked up spectacles). The distribution of compliance will be assessed for each treatment group at the outcome exam.
Time frame: 8 weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Compliance of Spectacle Wear | None (0%) | 0 Participants |
| Prism Group | Compliance of Spectacle Wear | Excellent (76% to 100%) | 22 Participants |
| Prism Group | Compliance of Spectacle Wear | Good (51% to 75%) | 3 Participants |
| Prism Group | Compliance of Spectacle Wear | Fair (26% to 50%) | 0 Participants |
| Prism Group | Compliance of Spectacle Wear | Poor (1% to 25%) | 0 Participants |
| Non-Prism Group | Compliance of Spectacle Wear | Poor (1% to 25%) | 0 Participants |
| Non-Prism Group | Compliance of Spectacle Wear | Fair (26% to 50%) | 1 Participants |
| Non-Prism Group | Compliance of Spectacle Wear | Excellent (76% to 100%) | 22 Participants |
| Non-Prism Group | Compliance of Spectacle Wear | None (0%) | 0 Participants |
| Non-Prism Group | Compliance of Spectacle Wear | Good (51% to 75%) | 2 Participants |
Secondary
Exodeviation by PACT at Distance, Continuous
The measure of ocular alignment at distance by PACT will be summarized at 8 weeks for each treatment group. A higher deviation is worse.
Time frame: 8 Weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prism Group | Exodeviation by PACT at Distance, Continuous | 30.6 prism diopters | Standard Deviation 9.3 |
| Non-Prism Group | Exodeviation by PACT at Distance, Continuous | 26.5 prism diopters | Standard Deviation 8.1 |
Secondary
Exodeviation by PACT at Near, Continuous
The measure of ocular alignment at near by PACT will be summarized at 8 weeks for each treatment group. A higher deviation is worse.
Time frame: 8 Weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prism Group | Exodeviation by PACT at Near, Continuous | 28.7 prism diopters | Standard Deviation 8.2 |
| Non-Prism Group | Exodeviation by PACT at Near, Continuous | 19.0 prism diopters | Standard Deviation 9.8 |
Secondary
Exotropia Control Score at Distance and Near, % With No Spontaneous Tropia
The proportion of participants with no spontaneous tropia at 8 weeks will be compared between treatment groups using a two-sided Barnard's test with alpha of 0.05, with calculation of a two-sided 95% confidence interval on the difference in proportions. No spontaneous tropia at the 8-week primary outcome exam is defined as a score of ≤2 (0, 1, or 2) on all three assessments of control at distance and at near.
Time frame: 8 Weeks
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Prism Group | Exotropia Control Score at Distance and Near, % With No Spontaneous Tropia | 48 percentage of participants |
| Non-Prism Group | Exotropia Control Score at Distance and Near, % With No Spontaneous Tropia | 51 percentage of participants |
95% CI: [-27, 19]
Secondary
Exotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks
Control of the exodeviation was measured at distance using the IXT Office Control Score, (Mohney, 2006) which ranges from 0 (phoria) to 5 (constant exotropia). Control levels 3-5 were assigned based on the duration of manifest exotropia during a 30-second period before any dissociation. If no exotropia was observed, control levels 0-2 were assigned based on the longest time to reestablishing fusion after 3 consecutive 10-second periods of dissociation. Control was measured at the beginning, middle, and end (3 tests) of a 20- to 40-minute office examination, and the mean was used. The change in distance control from baseline to 8 weeks will be calculated. A negative value indicates improvement.
Time frame: 8 Weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prism Group | Exotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks | 0.1 units on a scale | Standard Deviation 1.4 |
| Non-Prism Group | Exotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks | -0.2 units on a scale | Standard Deviation 1.5 |
Secondary
Exotropia Control Score at Distance, % With Treatment Response
The secondary analysis will calculate the percentage of participants with a treatment response, defined as ≥1 point improvement in control of their distance exodeviation (average of 3 measurements) between baseline and the 8-week outcome exam.
Time frame: 8 weeks
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Prism Group | Exotropia Control Score at Distance, % With Treatment Response | 32 percentage of participants |
| Non-Prism Group | Exotropia Control Score at Distance, % With Treatment Response | 24 percentage of participants |
95% CI: [-17, 32]
Secondary
Exotropia Control Score at Near, Continuous Score
Near control will be evaluated similarly to the primary outcome and outcome measures 2-4. Near control scores range from 0 to 5 with higher scores indicating a worse outcome.
Time frame: 8 Weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prism Group | Exotropia Control Score at Near, Continuous Score | 1.7 units on a scale | Standard Deviation 1.1 |
| Non-Prism Group | Exotropia Control Score at Near, Continuous Score | 1.7 units on a scale | Standard Deviation 1.3 |
Comparison: The secondary analysis was the treatment group difference (and 95% CI) in mean near control at the 8-week outcome visit using an ANCOVA adjusted for baseline near control.95% CI: [-0.7, 0.7]
Secondary
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?
Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Almost Never | 2 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Often | 1 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Sometimes | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Almost Always | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Never | 22 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Almost Always | 0 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Never | 15 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Almost Never | 6 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Sometimes | 3 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close? | Often | 1 Participants |
Secondary
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose?
Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Almost Never | 3 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Often | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Sometimes | 5 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Almost Always | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Never | 17 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Almost Always | 0 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Never | 14 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Almost Never | 5 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Sometimes | 5 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose? | Often | 1 Participants |
Secondary
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?
Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Almost Always | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Never | 16 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Almost Never | 5 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Sometimes | 4 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Often | 0 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Often | 1 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Sometimes | 9 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Never | 11 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Almost Always | 0 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain? | Almost Never | 4 Participants |
Secondary
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?
Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Almost Never | 8 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Often | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Sometimes | 2 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Almost Always | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Never | 15 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Almost Always | 0 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Never | 14 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Almost Never | 6 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Sometimes | 5 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches? | Often | 0 Participants |
Secondary
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?
Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Almost Never | 7 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Often | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Sometimes | 5 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Almost Always | 1 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Never | 12 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Almost Always | 0 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Never | 14 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Almost Never | 3 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Sometimes | 5 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles? | Often | 3 Participants |
Secondary
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?
Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Never | 21 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Often | 1 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Almost Never | 2 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Almost Always | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Sometimes | 1 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Almost Always | 0 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Sometimes | 1 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Never | 21 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Almost Never | 3 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision? | Often | 0 Participants |
Secondary
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them?
Adverse symptoms of intermittent exotropia and spectacle wear will be summarized at the 8-week outcome exam using a symptom survey that is administered to the parent. Response options are based on frequency of observations: never, almost never, sometimes, often, and almost always. The distribution of scores on each survey item will be tabulated by treatment group after 8-weeks.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Almost Never | 11 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Often | 3 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Sometimes | 6 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Almost Always | 0 Participants |
| Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Never | 5 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Almost Always | 1 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Never | 10 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Almost Never | 5 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Sometimes | 8 Participants |
| Non-Prism Group | Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Taken His/Her Spectacles Off When he/She Should be Wearing Them? | Often | 1 Participants |
Secondary
Randot Preschool Stereoacuity at Near, Continuous
Randot® Preschool Stereoacuity test (Stereo Optical Co., Inc., Chicago, IL). For analysis, stereoacuity was converted from seconds of arc scores to log arcsec values (in parentheses) as follows: 40 (1.60), 60 (1.78), 100 (2.00), 200 (2.30), 400 (2.60), 800 (2.90); participants with no detectable (nil) stereoacuity were assigned the value of 1600 (3.20). The measure of Randot Preschool Stereoacuity at near will be summarized at 8 weeks for each treatment group. A lower score is better.
Time frame: 8 Weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prism Group | Randot Preschool Stereoacuity at Near, Continuous | 2.2 log arc seconds | Standard Deviation 0.4 |
| Non-Prism Group | Randot Preschool Stereoacuity at Near, Continuous | 1.9 log arc seconds | Standard Deviation 0.4 |
Other Pre-specified
Distance Visual Acuity (Snellen Equivalent)
Distance visual acuity will be assessed at the 8-week outcome exam. Any optotype method can be used for testing. The distribution of distance visual acuity Snellen Equivalents will be tabulated for each treatment group. A lower Snellen Equivalent is best.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/20 | 10 Participants |
| Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/32 | 2 Participants |
| Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/25 | 9 Participants |
| Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/40 | 1 Participants |
| Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/16 (best) | 3 Participants |
| Non-Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/40 | 4 Participants |
| Non-Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/16 (best) | 1 Participants |
| Non-Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/20 | 9 Participants |
| Non-Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/25 | 8 Participants |
| Non-Prism Group | Distance Visual Acuity (Snellen Equivalent) | 20/32 | 3 Participants |
Other Pre-specified
Fusional Convergence - Continuous Break Point
As an exploratory analysis, the distribution of fusional convergence amplitude (break point, blur point, and recovery) at 8 weeks will be summarized for each treatment group. Fusional amplitudes are a measure of how well a participant can converge their eyes using fusional vergence. It is measured by increasing base-out prism to the point that the participant is no longer able to control the deviation. The total amount of fusion is the magnitude of the base-out prism the participant was able to overcome plus the magnitude of the deviation. A higher number of prism diopters for break point is better than a lower number. A lower number for recovery point is better than a higher number.
Time frame: 8 Weeks
Population: 3 participants in the Prism group and 2 participants in the Non-Prism group were unable to perform testing at 8 weeks and are not included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prism Group | Fusional Convergence - Continuous Break Point | 17.8 prism diopters | Standard Deviation 11.5 |
| Non-Prism Group | Fusional Convergence - Continuous Break Point | 17.5 prism diopters | Standard Deviation 10.9 |
Other Pre-specified
Fusional Convergence - Continuous Recovery Point
As an exploratory analysis, the distribution of fusional convergence amplitude (break point, blur point, and recovery) at 8 weeks will be summarized for each treatment group. Fusional amplitudes are a measure of how well a participant can converge their eyes using fusional vergence. It is measured by increasing base-out prism to the point that the participant is no longer able to control the deviation. The total amount of fusion is the magnitude of the base-out prism the participant was able to overcome plus the magnitude of the deviation. A higher number of prism diopters for break point is better than a lower number. A lower number for recovery is better than a higher number.
Time frame: 8 Weeks
Population: 3 participants in the Prism group and 2 participants in the Non-Prism group were unable to perform testing at 8 weeks and are not included.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prism Group | Fusional Convergence - Continuous Recovery Point | 9.4 prism diopters | Standard Deviation 10.1 |
| Non-Prism Group | Fusional Convergence - Continuous Recovery Point | 10.6 prism diopters | Standard Deviation 9.4 |
Other Pre-specified
Suppression
The suppression assessment is a standardized method of assessing the depth of suppression experienced while the participant is tropic (NOT aligned). Scoring is reported on an ordinal scale from 0 (no suppression) to 3 (dense suppression). Missing refers to cases in which participants were unable to understand the test and/or gave unreliable responses. As an exploratory analysis, the distribution of suppression level (none, mild, moderate, severe, missing) will be tabulated after 8 weeks by treatment group.
Time frame: 8 Weeks
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Prism Group | Suppression | Dense (3 suppression) | 12 Participants |
| Prism Group | Suppression | None (0 suppression) | 1 Participants |
| Prism Group | Suppression | Missing | 1 Participants |
| Prism Group | Suppression | Mild (1 suppression) | 5 Participants |
| Prism Group | Suppression | Moderate (2 suppression) | 6 Participants |
| Non-Prism Group | Suppression | Mild (1 suppression) | 3 Participants |
| Non-Prism Group | Suppression | Moderate (2 suppression) | 4 Participants |
| Non-Prism Group | Suppression | Dense (3 suppression) | 10 Participants |
| Non-Prism Group | Suppression | Missing | 3 Participants |
| Non-Prism Group | Suppression | None (0 suppression) | 5 Participants |