Discussion of the optimal timing for surgery in early-onset exotropia and the long-term postoperative effect

Abstract

Objective To investigate the optimal timing for surgery in early-onset exotropia(XT) and the long-term postoperative effect. Methods One hundred eleven cases diagnosed with XT before 3 years old who were followed up for at least 2 years after surgery were retrospectively analyzed. Logistic regression was used to study the possible factors of the postoperative orthotropia rate and postoperative synoptophore/Titmus stereopsis, such as the age of onset, age at surgery, the type of strabismus, preoperative synoptophore/Titmus stereopsis and postoperative eye position. Results Based on a chi-square test and Spearman correlation analysis, classification of intermittent and constant XT had a statistically significant correlation with the rate of long-term orthotropia (χ2= 4.125, P<0.05) . Classification of intermittent and constant XT (χ2=3.951, P<0.05) and the postoperative orthotropia (χ2=4.269, P<0.05) had a statistically significant correlation to postoperative synoptophore stereopsis. Classification of intermittent and constant XT had a statistically significant correlation to postoperative Titmus stereopsis (χ2=6.988, P<0.01) . Logistic regression analysis showed that the classification of intermittent and constant XT was the main factor affecting the long- term orthotropia rate (OR=0.445, P<0.05) . Preoperative synoptophore stereopsis was the main factor affecting postoperative synoptophore stereopsis (OR=10.500, P<0.01) . Preoperative Titmus stereopsis and the classification of intermittent and constant XT were the factors affecting postoperative Titmus stereopsis (OR=11.480, 0.175, P<0.05) . Conclusion It is suggested that patients with early-onset XT undergo surgery before the loss of binocular vision function. The loss of stereopsis function and the loss of the ability to control deviation were indications for exotropia surgery. Key words: Strabismus surgery; Exotropia; Infantile; Timing of operation; Vision, binocular