Relationship among clinical factors in childhood intermittent exotropia.

Purpose: To determine the relationships between stereoacuity, control of exotropia, and angle of deviation in children with intermittent exotropia (IXT).
Methods: Data collected for 652 participants 3 to <11 years of age with IXT meeting eligibility criteria for enrollment into one of two multicenter, randomized clinical trials were used to evaluate relationships between stereoacuity, control, and angle of deviation at enrollment.
Results: Any level of stereoacuity and angle of deviation could be accompanied by any level of control. Worse distance exotropia control was weakly associated with poorer distance stereoacuity (R = 0.26; 99% CI, 0.17-0.36) and larger angles of deviation at distance (R = 0.27; 99% CI, 0.17-0.36). Worse near exotropia control was weakly associated with poorer near stereoacuity (R = 0.17; 99% CI, 0.07-0.27) and moderately associated with larger angles of deviation at near (R = 0.37; 99% CI, 0.28-0.45). There was no association between stereoacuity and angle of deviation at distance (R = 0.07; 99% CI, -0.03 to 0.17) or at near (R = 0.02; 99% CI, -0.08 to 0.12).
Conclusions: Although weak and moderate associations were found between stereoacuity, control, and angle of deviation, a child may exhibit any combination of stereoacuity, control, and angle of deviation. The specific roles of control, stereoacuity, and angle of deviation in the diagnosis, management, and pathogenesis of IXT are unclear, and each appears to yield somewhat independent information.
(Copyright © 2017 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)