title: Acute acquired comitant esotropia related to excessive Smartphone use.
abstract: BACKGROUND
  To describe the clinical characteristics and outcomes of acute acquired comitant esotropia (AACE) related to excessive smartphone use in adolescents.
  
  
  METHODS
  The medical records of 12 patients with AACE and a history of excessive smartphone use were retrospectively reviewed, and the duration of smartphone use, angle of deviation, refractive error, stereopsis, and treatment options were analyzed.
  
  
  RESULTS
  All patients showed convergent and comitant esotropia ranging from 15 to 45 prism diopters (PD; average: 27.75 ± 11.47 PD) at far fixation. The angle of deviation was nearly equivalent for far and near fixation. Every patient used a smartphone for more than 4 h a day over a period of several months (minimum 4 months). Myopic refractive errors were detected in eight patients (average:-3.84 ± 1.68 diopters (D]), and the remaining four patients showed mild hyperopic refractive error (average: +0.84 ± 0.53 D). Reductions in esodeviation were noted in all patients after refraining from smartphone use, and bilateral medial rectus recession was performed in three patients with considerable remnant esodeviation. Postoperative exams showed orthophoria with good stereoacuity in these patients.
  
  
  CONCLUSIONS
  Excessive smartphone use might influence AACE development in adolescents. Refraining from smartphone use can decrease the degree of esodeviation in these patients, and remnant deviation can be successfully managed with surgical correction.
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School and Hospital, 42 Jebong-ro, Dong-Gu, Gwang-Ju, 61469, South Korea.
authors.forename: Hyo Seok
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School and Hospital, 42 Jebong-ro, Dong-Gu, Gwang-Ju, 61469, South Korea.
authors.forename: Sang Woo
authors.initials: SW
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School and Hospital, 42 Jebong-ro, Dong-Gu, Gwang-Ju, 61469, South Korea. opheye@hanmail.net.
authors.forename: Hwan
authors.initials: H
authors.lastname: Heo
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000294:Adolescent Behavior; D002648:Child; D016288:Computer Terminals; D003867:Depth Perception / Q000502:physiology; D004948:Esotropia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D012030:Refractive Errors / Q000503:physiopathology; D012189:Retrospective Studies; D000068997:Smartphone / Q000295:instrumentation / Q000706:statistics & numerical data*; D013997:Time Factors; D014792:Visual Acuity / Q000502:physiology
keywords: Esotropia; Medial rectus recession; Smartphone; Video display terminal