To evaluate the clinical features and treatment outcomes of smartphone overusers with acute acquired comitant esotropia.

We retrospectively reviewed the medical records of patients ≥ 15 years of age who used a smartphone for > 4 hours a day for > 1 year, and who were diagnosed with acute acquired comitant esotropia from May 2011 to January 2016. We analyzed sex, age at the time of manifestation and duration of esotropia, refractive error, deviated angle at the first and final visits, and the results of refraining from smartphone use, use of the Fresnel prism, and surgery for esotropia.

A total of 13 patients were studied, including 8 males and 5 females. The mean age at development of esotropia was 22.7 ± 9.7 years. The mean duration of esotropia before the first visit was 28.0 ± 33.0 months, and the mean follow-up period was 16.4 ± 16.4 months. The mean angle of esotropia was 21.8 ± 7.0 prism diopters (PD) at distance and 22.2 ± 7.9 PD at near. There were eight myopic patients; the other patients were emmetropia. The esotropia of all patients did not improve after refraining from smartphone use. There was no improvement in five patients who were wearing the Fresnel prism for ≥ 4 months. A total of six patients were treated with bilateral medial rectus recession; only one patient remained orthotropic at postoperative 6 months, three patients were undercorrected, and two had a recurrence.

Esotropia persisted after refraining from smartphone use or wearing a Fresnel prism in acute acquired comitant esotropia patients who were smartphone overusers, and the surgical prognosis of these patients was relatively poor.