Comparison of clinical features and long-term surgical outcomes in infantile constant and intermittent exotropia

Purpose: To evaluate the long-term surgical outcomes and the clinical features between infantile-onset constant and intermittent exotropia. Methods: The medical records of 67 patients diagnosed as having infantile exotropia before 12 months of age who underwent surgery were reviewed retrospectively. Patients were divided into intermittent exotropia and constant exotropia groups based on presentation before surgery. All patients underwent bilateral lateral rectus recession. Preoperative and postoperative clinical features were investigated. Results: There were 37 children in the intermittent exotropia group and 30 children in the constant exotropia group. The cumulative probabilities of success 3 years after bilateral lateral rectus recession were 91.9% in the intermittent exotropia group and 70% in the constant exotropia group. Constant deviation was more closely associated with both dissociated vertical deviation (DVD) and inferior oblique muscle overaction (IOOA) (P = .009 and P = .009, respectively) and related to poor stereopsis outcome (P = .002) and distance suppression (P = .029). Conclusions: Constant deviation was associated with the development of recurrence, DVD/IOOA, and poor stereopsis after surgery. Constancy of exotropia is a reliable factor for predicting poor surgical outcomes in infantile exotropia at long-term follow-up.