Evaluation of Exotropia After Patching the Eye or After Prism Adaptation

Divergence Excess/Simulated Divergence Excess Exotropia (DESDEE)

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.

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

Exclusion Criteria:

• No diagnosis of divergence excess exotropia according to standard criteria (see Study Procedures for specifics)
• Prior strabismus surgery
• Unable to cooperate with testing (by examiner determination)
• Diagnosed with a neurological disorder (ADHD and autism spectrum are not exclusion criteria as long as the subject can cooperate for necessary testing)
• Best-corrected visual acuity in either eye worse than 20/40
• 18 years of age or older
• Diagnosed with dissociated vertical deviation