Trial Outcomes & Findings for Base-in Prism Spectacles for Intermittent Exotropia (NCT NCT03998670)

NCT ID: NCT03998670

Last Updated: 2023-10-04

Results Overview

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.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

61 participants

Primary outcome timeframe

8 weeks

Results posted on

2023-10-04

Participant Flow

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).

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.

Participant milestones

Participant milestones
Measure
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
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
Overall Study
STARTED
28
29
Overall Study
COMPLETED
25
25
Overall Study
NOT COMPLETED
3
4

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Base-in Prism Spectacles for Intermittent Exotropia

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Prism Group
n=28 Participants
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
Non-Prism Group
n=29 Participants
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
Total
n=57 Participants
Total of all reporting groups
Suppression
None (0 suppression)
3 Participants
n=5 Participants
3 Participants
n=7 Participants
6 Participants
n=5 Participants
Age, Categorical
<=18 years
28 Participants
n=5 Participants
29 Participants
n=7 Participants
57 Participants
n=5 Participants
Age, Categorical
Between 18 and 65 years
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Age, Categorical
>=65 years
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Age, Continuous
6.4 years
STANDARD_DEVIATION 2.4 • n=5 Participants
6.8 years
STANDARD_DEVIATION 2.1 • n=7 Participants
6.6 years
STANDARD_DEVIATION 2.2 • n=5 Participants
Age, Customized
3 to <5 years
10 Participants
n=5 Participants
7 Participants
n=7 Participants
17 Participants
n=5 Participants
Age, Customized
5 to <7 years
7 Participants
n=5 Participants
10 Participants
n=7 Participants
17 Participants
n=5 Participants
Age, Customized
7 to <9 years
8 Participants
n=5 Participants
8 Participants
n=7 Participants
16 Participants
n=5 Participants
Age, Customized
>=9 years
3 Participants
n=5 Participants
4 Participants
n=7 Participants
7 Participants
n=5 Participants
Sex: Female, Male
Female
17 Participants
n=5 Participants
16 Participants
n=7 Participants
33 Participants
n=5 Participants
Sex: Female, Male
Male
11 Participants
n=5 Participants
13 Participants
n=7 Participants
24 Participants
n=5 Participants
Race/Ethnicity, Customized
Asian
0 Participants
n=5 Participants
3 Participants
n=7 Participants
3 Participants
n=5 Participants
Race/Ethnicity, Customized
Black/African American
6 Participants
n=5 Participants
2 Participants
n=7 Participants
8 Participants
n=5 Participants
Race/Ethnicity, Customized
Hispanic
4 Participants
n=5 Participants
7 Participants
n=7 Participants
11 Participants
n=5 Participants
Race/Ethnicity, Customized
White
16 Participants
n=5 Participants
17 Participants
n=7 Participants
33 Participants
n=5 Participants
Race/Ethnicity, Customized
More than one race
2 Participants
n=5 Participants
0 Participants
n=7 Participants
2 Participants
n=5 Participants
Region of Enrollment
United States
28 participants
n=5 Participants
29 participants
n=7 Participants
57 participants
n=5 Participants
Refractive Error Average of Eyes, Continuous
0.3 Spherical Equivalent Diopters
STANDARD_DEVIATION 1.0 • n=5 Participants
0.1 Spherical Equivalent Diopters
STANDARD_DEVIATION 1.4 • n=7 Participants
0.2 Spherical Equivalent Diopters
STANDARD_DEVIATION 1.2 • n=5 Participants
Refractive Error Average of Eyes, Categorical
-6.00 to <-2.00 diopters
1 Participants
n=5 Participants
3 Participants
n=7 Participants
4 Participants
n=5 Participants
Refractive Error Average of Eyes, Categorical
-2.00 to <-1.00 diopters
2 Participants
n=5 Participants
0 Participants
n=7 Participants
2 Participants
n=5 Participants
Refractive Error Average of Eyes, Categorical
-1.00 to <-0.00 diopters
4 Participants
n=5 Participants
4 Participants
n=7 Participants
8 Participants
n=5 Participants
Refractive Error Average of Eyes, Categorical
0.00 to <1.00 diopters
12 Participants
n=5 Participants
16 Participants
n=7 Participants
28 Participants
n=5 Participants
Refractive Error Average of Eyes, Categorical
1.00 to <2.00 diopters
9 Participants
n=5 Participants
6 Participants
n=7 Participants
15 Participants
n=5 Participants
Treatment for Intermittent Exotropia Prior to Enrollment
Overminus Lenses
2 Participants
n=5 Participants
3 Participants
n=7 Participants
5 Participants
n=5 Participants
Treatment for Intermittent Exotropia Prior to Enrollment
Patching
7 Participants
n=5 Participants
5 Participants
n=7 Participants
12 Participants
n=5 Participants
Treatment for Intermittent Exotropia Prior to Enrollment
Patching and Atropine
0 Participants
n=5 Participants
1 Participants
n=7 Participants
1 Participants
n=5 Participants
Treatment for Intermittent Exotropia Prior to Enrollment
Patching and Overminus Lenses
1 Participants
n=5 Participants
0 Participants
n=7 Participants
1 Participants
n=5 Participants
Treatment for Intermittent Exotropia Prior to Enrollment
Vision Therapy and Overminus Lenses
0 Participants
n=5 Participants
1 Participants
n=7 Participants
1 Participants
n=5 Participants
Treatment for Intermittent Exotropia Prior to Enrollment
None
18 Participants
n=5 Participants
19 Participants
n=7 Participants
37 Participants
n=5 Participants
Randot Preschool Stereoacuity at Near, Continuous
2.3 log arcsec
STANDARD_DEVIATION 0.4 • n=5 Participants
2.3 log arcsec
STANDARD_DEVIATION 0.5 • n=7 Participants
2.3 log arcsec
STANDARD_DEVIATION 0.4 • n=5 Participants
Randot Preschool Stereoacuity at Near, Categorical
40 (1.60)
2 Participants
n=5 Participants
3 Participants
n=7 Participants
5 Participants
n=5 Participants
Randot Preschool Stereoacuity at Near, Categorical
60 (1.78)
6 Participants
n=5 Participants
8 Participants
n=7 Participants
14 Participants
n=5 Participants
Randot Preschool Stereoacuity at Near, Categorical
100 (2.00)
9 Participants
n=5 Participants
7 Participants
n=7 Participants
16 Participants
n=5 Participants
Randot Preschool Stereoacuity at Near, Categorical
200 (2.30)
3 Participants
n=5 Participants
4 Participants
n=7 Participants
7 Participants
n=5 Participants
Randot Preschool Stereoacuity at Near, Categorical
400 (2.60)
5 Participants
n=5 Participants
3 Participants
n=7 Participants
8 Participants
n=5 Participants
Randot Preschool Stereoacuity at Near, Categorical
800 (2.90)
2 Participants
n=5 Participants
2 Participants
n=7 Participants
4 Participants
n=5 Participants
Randot Preschool Stereoacuity at Near, Categorical
Nil (3.10)
1 Participants
n=5 Participants
2 Participants
n=7 Participants
3 Participants
n=5 Participants
Suppression
Mild (1 suppression)
1 Participants
n=5 Participants
4 Participants
n=7 Participants
5 Participants
n=5 Participants
Suppression
Moderate (2 suppression)
4 Participants
n=5 Participants
8 Participants
n=7 Participants
12 Participants
n=5 Participants
Suppression
Dense (3 suppression)
18 Participants
n=5 Participants
10 Participants
n=7 Participants
28 Participants
n=5 Participants
Suppression
Missing
2 Participants
n=5 Participants
4 Participants
n=7 Participants
6 Participants
n=5 Participants
Exotropia Control Score at Distance, Continuous
3.4 units on a scale
STANDARD_DEVIATION 0.9 • n=5 Participants
3.5 units on a scale
STANDARD_DEVIATION 0.9 • n=7 Participants
3.5 units on a scale
STANDARD_DEVIATION 0.9 • n=5 Participants
Exotropia Control Score at Near, Continuous
2.3 units on a scale
STANDARD_DEVIATION 1.3 • n=5 Participants
1.7 units on a scale
STANDARD_DEVIATION 1.1 • n=7 Participants
2.0 units on a scale
STANDARD_DEVIATION 1.2 • n=5 Participants
Exotropia Control Score at Distance, Categorical
0 to <1 unit
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Exotropia Control Score at Distance, Categorical
1 to <2 units
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Exotropia Control Score at Distance, Categorical
2 to <3 units
8 Participants
n=5 Participants
8 Participants
n=7 Participants
16 Participants
n=5 Participants
Exotropia Control Score at Distance, Categorical
3 to <4 units
10 Participants
n=5 Participants
10 Participants
n=7 Participants
20 Participants
n=5 Participants
Exotropia Control Score at Distance, Categorical
4 to 5 units
10 Participants
n=5 Participants
11 Participants
n=7 Participants
21 Participants
n=5 Participants
Exotropia Control Score at Near, Categorical
0 to 1 unit
2 Participants
n=5 Participants
6 Participants
n=7 Participants
8 Participants
n=5 Participants
Exotropia Control Score at Near, Categorical
1 to <2 units
9 Participants
n=5 Participants
9 Participants
n=7 Participants
18 Participants
n=5 Participants
Exotropia Control Score at Near, Categorical
2 to <3 units
6 Participants
n=5 Participants
9 Participants
n=7 Participants
15 Participants
n=5 Participants
Exotropia Control Score at Near, Categorical
3 to <4 units
6 Participants
n=5 Participants
4 Participants
n=7 Participants
10 Participants
n=5 Participants
Exotropia Control Score at Near, Categorical
4 to 5 units
5 Participants
n=5 Participants
1 Participants
n=7 Participants
6 Participants
n=5 Participants
Exodeviation by PACT at Distance, Categorical
1 to 9 pd
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Exodeviation by PACT at Distance, Categorical
10 to 15 pd
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Exodeviation by PACT at Distance, Categorical
16 to 18 pd
3 Participants
n=5 Participants
5 Participants
n=7 Participants
8 Participants
n=5 Participants
Exodeviation by PACT at Distance, Categorical
20 to 25 pd
18 Participants
n=5 Participants
15 Participants
n=7 Participants
33 Participants
n=5 Participants
Exodeviation by PACT at Distance, Categorical
30 to 35 pd
7 Participants
n=5 Participants
9 Participants
n=7 Participants
16 Participants
n=5 Participants
Exodeviation by PACT at Distance, Categorical
40 to 45 pd
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Exodeviation by PACT at Distance, Continuous
25.1 Prism Diopters (pd)
STANDARD_DEVIATION 4.7 • n=5 Participants
24.9 Prism Diopters (pd)
STANDARD_DEVIATION 5.6 • n=7 Participants
25.0 Prism Diopters (pd)
STANDARD_DEVIATION 5.2 • n=5 Participants
Exodeviation by PACT at Near, Categorical
1 to 9 pd
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Exodeviation by PACT at Near, Categorical
10 to 15 pd
2 Participants
n=5 Participants
6 Participants
n=7 Participants
8 Participants
n=5 Participants
Exodeviation by PACT at Near, Categorical
16 to 18 pd
8 Participants
n=5 Participants
7 Participants
n=7 Participants
15 Participants
n=5 Participants
Exodeviation by PACT at Near, Categorical
20 to 25 pd
15 Participants
n=5 Participants
8 Participants
n=7 Participants
23 Participants
n=5 Participants
Exodeviation by PACT at Near, Categorical
30 to 35 pd
3 Participants
n=5 Participants
8 Participants
n=7 Participants
11 Participants
n=5 Participants
Exodeviation by PACT at Near, Categorical
40 to 45 pd
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Exodeviation by PACT at Near, Continuous
21.5 Prism Diopters (pd)
STANDARD_DEVIATION 5.1 • n=5 Participants
21.1 Prism Diopters (pd)
STANDARD_DEVIATION 7.5 • n=7 Participants
21.3 Prism Diopters (pd)
STANDARD_DEVIATION 6.4 • n=5 Participants

PRIMARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Exotropia Control Score at Distance, Continuous Score
3.6 units on a scale
Standard Deviation 1.3
3.3 units on a scale
Standard Deviation 1.5

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Exotropia Control Score at Distance, % With Treatment Response
32 percentage of participants
24 percentage of participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Exotropia Control Score at Distance and Near, % With No Spontaneous Tropia
48 percentage of participants
51 percentage of participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Exotropia Control Score at Distance, Continuous Change Between Baseline and 8 Weeks
0.1 units on a scale
Standard Deviation 1.4
-0.2 units on a scale
Standard Deviation 1.5

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Exotropia Control Score at Near, Continuous Score
1.7 units on a scale
Standard Deviation 1.1
1.7 units on a scale
Standard Deviation 1.3

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Exodeviation by PACT at Distance, Continuous
30.6 prism diopters
Standard Deviation 9.3
26.5 prism diopters
Standard Deviation 8.1

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Exodeviation by PACT at Near, Continuous
28.7 prism diopters
Standard Deviation 8.2
19.0 prism diopters
Standard Deviation 9.8

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Randot Preschool Stereoacuity at Near, Continuous
2.2 log arc seconds
Standard Deviation 0.4
1.9 log arc seconds
Standard Deviation 0.4

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Compliance of Spectacle Wear
Excellent (76% to 100%)
22 Participants
22 Participants
Compliance of Spectacle Wear
Good (51% to 75%)
3 Participants
2 Participants
Compliance of Spectacle Wear
Fair (26% to 50%)
0 Participants
1 Participants
Compliance of Spectacle Wear
Poor (1% to 25%)
0 Participants
0 Participants
Compliance of Spectacle Wear
None (0%)
0 Participants
0 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Child Assessment of Symptoms - Do Your Eyes Hurt?
Never
15 Participants
22 Participants
Child Assessment of Symptoms - Do Your Eyes Hurt?
Sometimes
6 Participants
3 Participants
Child Assessment of Symptoms - Do Your Eyes Hurt?
Almost Always
4 Participants
0 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Child Assessment of Symptoms - Do Your Eyes Feel Funny?
Never
17 Participants
20 Participants
Child Assessment of Symptoms - Do Your Eyes Feel Funny?
Sometimes
7 Participants
3 Participants
Child Assessment of Symptoms - Do Your Eyes Feel Funny?
Almost Always
1 Participants
2 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Child Assessment of Symptoms - Do You Have Double Vision?
Never
17 Participants
17 Participants
Child Assessment of Symptoms - Do You Have Double Vision?
Sometimes
8 Participants
7 Participants
Child Assessment of Symptoms - Do You Have Double Vision?
Almost Always
0 Participants
1 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Child Assessment of Symptoms - Is it Hard for You to Stare at Things?
Never
16 Participants
15 Participants
Child Assessment of Symptoms - Is it Hard for You to Stare at Things?
Sometimes
7 Participants
8 Participants
Child Assessment of Symptoms - Is it Hard for You to Stare at Things?
Almost Always
2 Participants
2 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun?
Never
11 Participants
14 Participants
Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun?
Sometimes
8 Participants
5 Participants
Child Assessment of Symptoms - Do You Have Problems With Your Eyes in the Sun?
Almost Always
6 Participants
6 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Child Assessment of Symptoms - Do Your Eyes go in and Out?
Never
20 Participants
19 Participants
Child Assessment of Symptoms - Do Your Eyes go in and Out?
Sometimes
2 Participants
3 Participants
Child Assessment of Symptoms - Do Your Eyes go in and Out?
Almost Always
3 Participants
3 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Child Assessment of Symptoms - Is it Hard to Focus Your Eyes?
Never
16 Participants
12 Participants
Child Assessment of Symptoms - Is it Hard to Focus Your Eyes?
Sometimes
5 Participants
11 Participants
Child Assessment of Symptoms - Is it Hard to Focus Your Eyes?
Almost Always
4 Participants
2 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?
Never
15 Participants
14 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?
Almost Never
8 Participants
6 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?
Sometimes
2 Participants
5 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?
Often
0 Participants
0 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Headaches?
Almost Always
0 Participants
0 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?
Never
16 Participants
11 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?
Almost Never
5 Participants
4 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?
Sometimes
4 Participants
9 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?
Often
0 Participants
1 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Had Eyestrain?
Almost Always
0 Participants
0 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?
Never
22 Participants
15 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?
Almost Never
2 Participants
6 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?
Sometimes
0 Participants
3 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?
Often
1 Participants
1 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Avoided Reading or Doing Things up Close?
Almost Always
0 Participants
0 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?
Never
21 Participants
21 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?
Almost Never
2 Participants
3 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?
Sometimes
1 Participants
1 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?
Often
1 Participants
0 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Reported Blurry Vision?
Almost Always
0 Participants
0 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?
Never
12 Participants
14 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?
Almost Never
7 Participants
3 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?
Sometimes
5 Participants
5 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?
Often
0 Participants
3 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Looked Over His or Her Spectacles?
Almost Always
1 Participants
0 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
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
10 Participants
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
5 Participants
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
8 Participants
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
1 Participants
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
1 Participants

SECONDARY outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose?
Never
17 Participants
14 Participants
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
5 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose?
Sometimes
5 Participants
5 Participants
Parent Assessment of Symptoms and Spectacle Wear - Has Your Child Complained That the Spectacles Hurt His/Her Ears and/or Nose?
Often
0 Participants
1 Participants
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
0 Participants

OTHER_PRE_SPECIFIED outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Distance Visual Acuity (Snellen Equivalent)
20/16 (best)
3 Participants
1 Participants
Distance Visual Acuity (Snellen Equivalent)
20/20
10 Participants
9 Participants
Distance Visual Acuity (Snellen Equivalent)
20/25
9 Participants
8 Participants
Distance Visual Acuity (Snellen Equivalent)
20/32
2 Participants
3 Participants
Distance Visual Acuity (Snellen Equivalent)
20/40
1 Participants
4 Participants

OTHER_PRE_SPECIFIED outcome

Timeframe: 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.

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.

Outcome measures

Outcome measures
Measure
Prism Group
n=22 Participants
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
Non-Prism Group
n=23 Participants
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
Fusional Convergence - Continuous Break Point
17.8 prism diopters
Standard Deviation 11.5
17.5 prism diopters
Standard Deviation 10.9

OTHER_PRE_SPECIFIED outcome

Timeframe: 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.

Outcome measures

Outcome measures
Measure
Prism Group
n=25 Participants
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
Non-Prism Group
n=25 Participants
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
Suppression
None (0 suppression)
1 Participants
5 Participants
Suppression
Mild (1 suppression)
5 Participants
3 Participants
Suppression
Moderate (2 suppression)
6 Participants
4 Participants
Suppression
Dense (3 suppression)
12 Participants
10 Participants
Suppression
Missing
1 Participants
3 Participants

OTHER_PRE_SPECIFIED outcome

Timeframe: 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.

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.

Outcome measures

Outcome measures
Measure
Prism Group
n=22 Participants
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
Non-Prism Group
n=23 Participants
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
Fusional Convergence - Continuous Recovery Point
9.4 prism diopters
Standard Deviation 10.1
10.6 prism diopters
Standard Deviation 9.4

Adverse Events

Prism Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Non-Prism Group

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Raymond Kraker, PEDIG Coordinating Center Director

PEDIG Coordinating Center, Jaeb Center for Health Research

Phone: 813 975 8690

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place