The Effect of Near-work on the Development of Delayed-onset Consecutive Esotropia

Purpose: To identify the correlation between near work and the occurrence of delayed-onset consecutive esotropia after surgery for intermittent exotropia. Methods: A survey and retrospective review were conducted on patients in two groups. The study included patients who visited from January 2019 to January 2020. Patients who re-developed esodeviation after recovering orthophoria after the initial postoperative overcorrection for the surgical correction of intermittent exotropia were included in the delayed-onset esotropia group (Group 1), and patients with persistent orthotropia for at least 3 years after bilateral lateral rectus recession for intermittent exotropia were included in Group 2. We evaluated the daily frequency and hours of distance/near work in both groups. Results: A total of 42 patients were evaluated. Preoperative exodeviation at a distance was 28.5 +/- 4.4 prism diopters (PD) in group 1 and 30.5 +/- 5.2 PD in group 2, with no significant difference between the two groups. The percentages of patients who chose two or more extremely near-work activities a day were 47.8% and 15.8% for groups 1 and 2, respectively; these values were statistically significant (p = 0.02). Twelve patients in Group 2 answered watching TV (63.2%) as the most common activity, which was statistically significant compared to Group 1 (26.1% in Group 1, p = 0.02). The total numbers of hours of extremely near-work a day were 2.7 +/- 2.1 and 1.5 +/- 1.2 hours for groups 1 and 2, respectively, which was also statistically significant (p = 0.037). Conclusions: We found a significant correlation with occurrence of delayed-onset consecutive esotropia with the frequency and hours of extremely near-work after bilateral lateral rectus recession for intermittent exotropia. More attention to extremely near-work should be considered carefully after bilateral lateral rectus recession for intermittent exotropia.

Automated summary

This study investigated the correlation between near work and delayed-onset consecutive esotropia after surgery for intermittent exotropia. The frequency and hours of near work were found to be significantly associated with the occurrence of esotropia, suggesting the importance of closely monitoring near work activities postoperatively.