Exotropia
Conditions
Brief summary
This study intends to determine the number and percent of subjects initially diagnosed with divergence excess exotropia which would be reclassified as simulated divergence excess exotropia if tested after 24 hours of monocular occlusion (patching) or after prism adaptation for the distance angle.
Interventions
PROCEDUREPatching
The subject will occlude the non-dominant eye for 24 hours.
PROCEDUREPrism Adaptation
The subject will undergo prism adaptation targeting the pre-occlusion distance angle for 1-2 weeks. • Fresnel prism(s) will be applied to the patient's spectacles equaling the distance angle between the two eyes. At the examiner's discretion depending on the size of the deviation, the prism(s) can be placed solely over the non-dominant eye, or split between the 2 eyes in some combination which results in equalization of the distance exotropia. If the distance angle calls for an amount of prism that cannot be exactly replicated with Fresnel prisms (e.g., 32 PD), the amount of prism used will be determined by rounding down to the nearest practical amount at examiner discretion.
Sponsors
University of Rochester
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
No minimum to 17 Years
Healthy volunteers
No
Inclusion criteria
* Diagnosed with divergence excess exotropia according to standard criteria (see Study Procedures for specifics) * No prior strabismus surgery * Able to cooperate with testing (by examiner determination) * Neurologically normal except for strabismus (ADHD and autism spectrum are not
Exclusion criteria
as long as the subject can cooperate for necessary testing) * Not amblyopic at the time of enrollment (best-corrected visual acuity in both eyes of 20/40 or better) * Under 18 years of age. There is no lower age limit as long as the subject can cooperate for the required testing. * No diagnosis of dissociated vertical deviation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percent of participants reclassified as divergence excess exotropia | 2 weeks | Percentage of patients with distance and near exotropia measurements within 2.5 prism diopters on alternate prism and cover testing after 24 hours of patching or 7-14 days of fresnel prism use. |
| Percent of participants reclassified as simulated divergence excess exotropia | 2 weeks | Percentage of patients with distance and near exotropia measurements differing by more than 2.5 prism diopters on alternate prism and cover testing after 24 hours of patching or 7-14 days of fresnel prism use. |
Countries
Canada, India, Israel, Italy, United States
Outcome results
None listed