Purpose: To investigate risk factors predisposing to the failure of nonsurgical treatment of consecutive esotropia.Methods: A retrospective review was carried out for all cases diagnosed as having developed consecutive esotropia who following surgical correction of intermittent exotropia between 2013 and 2018 and have failed to conservative treatment. Performing 1:2 case-control match, control subjects were randomly selected from patients who underwent surgeries for intermittent exotropia during the same period but did not develop consecutive esotropia. Various factors were examined for assessing the risks for the failure of nonsurgical intervention in the treatment of consecutive esotropia.Results: A total of 270 patients were enrolled in the study. Ninety cases were diagnosed as consecutive esotropia and 180 as controls. Univariate analysis showed significant association of consecutive esotropia for ineffective nonsurgical treatment with age of the patient at the onset of exotropia, age of the patient at the time of surgery, amblyopia, preoperative deviation, the type of surgical procedure, and the vertical components combined with exotropia (p<0.01).To further explore potential risk factors of consecutive esotropia, conditional logistic regression model was applied. Patients aged below 3 years old at the time of surgery and bilateral lateral rectus recession were shown in conditional logistic regression analysis to be significantly associated with higher incidence of consecutive esotropia (p<0.01).Conclusion: The presence of an early age (below 3 years old) at surgery and bilateral symmetric procedure may be associated with a high risk of consecutive esotropia who failed with conservative therapy. Systematic preoperative examination, close supervision, suitable surgical approach could be optimized to reduce the risk of consecutive esotropia.
Keywords: Consecutive esotropia; conservative therapy; intermittent exotropia; risk factor; surgery.