Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.
Inclusion Criteria:
Children under the care of a pediatric optometrist or pediatric ophthalmologist will be
eligible for the study if they meet all the following criteria:
1. Age 3 to < 9 years
2. IXT meeting all of the following criteria:
- Intermittent or constant XT at distance (mean distance control 2.0 or more) with
at least 1 control measure of 3, 4 or 5 (i.e., indicating spontaneous tropia)
- Either IXT, exophoria, or orthophoria at near (cannot have control score of 5 on
all 3 near assessments)
- Distance exodeviation between 15? and 50? by PACT
- Near exodeviation between 0? and 50? by PACT
- Near exodeviation does not exceed distance by more than 10? by PACT (convergence
insufficiency-type IXT excluded)
3. Age-normal visual acuity in both eyes:
- 3 years: 20/50 or better (>=63 letters)
- 4 years: 20/40 or better (>=68 letters)
- 5-6 years: 20/32 or better (>=73 letters)
- 7-<9 years: 20/25 or better (>=78 letters)
4. Interocular difference in distance VA of 2 logMAR lines or less (10 letters or less on
E-ETDRS for patients ≥7 years old). Testing by ATS HOTV for participants 3 to < 7
years old and by E-ETDRS for participants ≥7 years old.
5. Cycloplegic refraction within the last 7 months.
6. Refractive error between -6.00 D SE and +2.00 D SE (inclusive) based on a cycloplegic
refraction within 7 months
7. Participants with refractive error meeting any of the following based on a cycloplegic
refraction within 6 months must be wearing spectacles for at least 2 weeks:
- Myopia > -0.50 D spherical equivalent (SE) in either eye
- Anisometropia > 1.00 D SE
- Astigmatism in either eye > 1.00 D
8. Any refractive correction worn at enrollment (required or not) must meet the following
guidelines based on a cycloplegic refraction within 7 months:
- Anisometropia SE must be within 0.50 D of the full anisometropic difference
correction
- Astigmatism must be corrected within 0.50 D
- Axis must be within ±10 degrees if cylinder power is ≤1.00 D and within ±5
degrees if cylinder power is >1.00 D.
- For hyperopia, the spherical component can be reduced at investigator discretion
provided the reduction is symmetrical and does not meet the definition of
deliberate overminus (see below).
- For myopia, the intent is to fully correct, but the spherical component can be
undercorrected at investigator discretion provided the reduction is symmetrical
and results in no more than -0.50 D SE residual (i.e., uncorrected) myopia.
Deliberate overminus is not allowed.
- Deliberate overminus is defined for this protocol as any refractive correction
prescribed to yield lenses that are overminused by more than -0.50D SE than
cycloplegic refraction SE
- Less than the full cycloplegic hyperopic correction (i.e., prescribing
reduced plus) is not considered the same as overminusing for this protocol
(because most patients without IXT but with hyperopic SE refractions up to
+2.00 D SE would not typically be prescribed a refractive correction.)
- For refractive errors with an emmetropic or myopic SE, the intent is to fully
correct, but the spherical component can be undercorrected at investigator
discretion provided the reduction is symmetrical and results in no more than
-0.50 D SE residual (i.e., uncorrected) myopia. Prescribing a correction that
yields more than 0.50 D more minus SE than the cycloplegic refraction SE is
considered deliberate overminus and is not allowed.
- Note that the refractive correction guidelines and the requirement to wear
refractive correction for at least 2 weeks apply not only to participants who
require refractive correction under the above criteria but also to any other
participant who is wearing refractive correction.
9. Gestational age > 30 weeks
10. Birth weight > 1500 grams
11. Patient and/or parent understands protocol, is willing to enroll, and is willing to
accept that other (i.e., nonrandomized) treatment for IXT will not be offered by the
investigator for 3 months
12. Parent has phone and is willing to be contacted by Jaeb Center staff
13. Relocation outside of area of an active PEDIG site within 3 months not anticipated
Exclusion Criteria:
Individuals meeting any of the following criteria at baseline will be excluded from study
participation:
1. Prior strabismus, intraocular, or refractive surgery (including BOTOX injection)
2. Prior nonsurgical treatment for IXT (e.g., patching, vergence therapy, vision
therapy/orthoptics, base-in prism, or deliberate overminus (more than 1.00 D)
spectacles of >1week duration within the past year
3. Previous amblyopia treatment other than refractive correction
4. Diplopia more than 2 times per day by parental assessment
5. Paretic or restrictive strabismus
6. Craniofacial malformations affecting the orbits
7. Ocular disorders which would reduce VA (except refractive error)
8. Severe developmental delay that would interfere with treatment or evaluation (in the
opinion of the investigator). Participants with mild speech delay or reading and/or
learning disabilities or ADHD are not excluded.
9. Neurological anomaly that could affect ocular motility (e.g., cerebral palsy, Down
syndrome)
10. Immediate family member (child or sibling) of any investigative site personnel
directly affiliated with this study.
11. Known allergy to adhesive patches.
12. Known allergy to silicone.
Eligibility last updated 8/9/22. Questions regarding updates should be directed to the study team contact.