Strabismus, a common ocular condition, arises from an imbalance in the extraocular muscle force and deviation of the visual axis due to various factors. Concomitant strabismus is the predominant form of exotropia, with its pathogenesis believed to be associated with hereditary factors, abnormal eye accommodation function, and anomalies in binocular anatomy. Surgical intervention is often necessary for aligning the visual axes of both eyes and facilitating the recovery and establishment of stereoscopic vision. Despite this, the etiology of concomitant exotropia remains incompletely understood. This review consolidates recent research on aberrant molecular expression and pathological morphological changes within extraocular muscles affected by concomitant exotropia, offering insights into disease causation at molecular and pathological levels to underpin future preventive measures and clinical interventions. The discussion encompasses histological changes observed under electron microscopy as well as the impact of heavy chain protein, satellite cells, cadherin, growth factors on extraocular muscle protein expression.