Motor Skill Deficits and Associated Factors in Childhood Intermittent Exotropia: A Cross-Sectional Study

The purpose of this study was to evaluate motor skill impairments in children with intermittent exotropia (IXT), and to investigate associations between clinical visual parameters and motor deficits.

In this cross-sectional study, motor proficiency in children with basic-type IXT and age-matched controls was evaluated using the Movement Assessment Battery for Children, Second Edition (MABC-2). All participants had normal best-corrected visual acuity (BCVA). This yielded scores for Total Motor Score, manual dexterity, aiming and catching, and balance. Within the IXT cohort, key ophthalmic characteristics, including deviation control, stereoacuity, and suppression, were documented. Group differences were analyzed, and relationships between visual features and MABC-2 scores in the IXT group were assessed using Spearman's correlation and multivariable regression models. Sensitivity analyses were performed to confirm the robustness of findings.

Children with IXT demonstrated significantly lower Total Motor Score than controls (P < 0.001), with specific deficits in manual dexterity (P < 0.001) and balance (P < 0.001), aiming and catching scores were comparable between groups (P = 0.332). Within the IXT cohort, poorer manual dexterity was significantly associated with reduced stereoacuity. Furthermore, aiming and catching performance was associated with the presence of sensory suppression.

Childhood IXT, despite its intermittent nature, is associated with broad motor deficits extending beyond the ocular motor system. These functional impairments are related to the condition's underlying sensory adaptations. Our findings reveal the widespread implications of disordered binocular vision and underscore the necessity of monitoring motor development in these patients.