title: Comparison of Surgical Outcomes with Unilateral Recession and Resection According to Angle of Deviation in Basic Intermittent Exotropia.
abstract: OBJECTIVE
  The purpose of this study is to compare the surgical outcomes and near stereoacuities after unilateral medial rectus (MR) muscle resection and lateral rectus (LR) recession according to deviation angle in basic intermittent exotropia, X(T).
  
  
  METHODS
  Ninety patients with basic type X(T) were included in this study. They underwent unilateral recession of the LR and resection of the MR and were followed postoperatively for at least 12 months. Patients were divided into three groups according to their preoperative deviation angle: group 1 ≤20 prism diopter (PD), 20 PD< group 2 <40 PD, and group 3 ≥40 PD. Surgical outcomes and near stereoacuities one year after surgery were evaluated. Surgical success was defined as having a deviation angle range within ±10 PD for both near and distance fixation.
  
  
  RESULTS
  Among 90 patients, groups 1, 2, and 3 included 30 patients each. The mean age in groups 1, 2, and 3 was 9.4 years, 9.4 years, and 11.0 years, respectively. The surgical success rates one year after surgery for groups 1, 2, and 3 were 80.0%, 73.3%, and 73.3% (chi-square test, p = 0.769), respectively. The undercorrection rates for groups 1, 2, and 3 were 16.7%, 23.3%, and 26.7%, and the overcorrection rates were 3.3%, 3.3%, and 0%, respectively. The mean preoperative near stereoacuities for groups 1, 2, and 3 were 224.3 arcsec, 302.0 arcsec, and 1,107.3 arcsec, and the mean postoperative near stereoacuities were 218.3 arcsec, 214.7 arcsec, and 743.0 arcsec (paired t-test; p = 0.858, p = 0.379, p = 0.083), respectively.
  
  
  CONCLUSIONS
  In basic X(T) patients, the amount of angle deviation has no influence on surgical outcomes in unilateral LR recession and MR resection. The near stereoacuities by one year after LR recession and MR resection for intermittent X(T) were not different among patient groups separated by preoperative deviation angle.
authors.affiliation: Department of Ophthalmology, Dongguk University College of Medicine, Gyeongju, Korea.
authors.forename: Soon Young
authors.initials: SY
authors.lastname: Cho
authors.affiliation: Department of Ophthalmology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Se Youp
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Myongji Hospital, Goyang, Korea.
authors.forename: Jong Hyun
authors.initials: JH
authors.lastname: Jung
mesh_terms: D002648:Child; D005099:Exotropia / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures; D012189:Retrospective Studies; D016896:Treatment Outcome; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology
keywords: Angle of deviation; Exotropia; Stereopsis; Surgical outcome