title: Type of the recurrent exotropia after bilateral rectus recession for intermittent exotropia.
abstract: BACKGROUND
  The aim of this study was to investigate the type of exotropia (XT) based on the distance-near (D/N) difference in recurrent XT after bilateral lateral rectus (BLR) recession to treat intermittent XT (IXT) to look into the possibility of secondary convergence insufficiency (CI)-type strabismus.
  
  
  METHODS
  A total of 121 patients with recurrent XT after BLR recession for basic-type and divergence excess (DE)-type IXT were retrospectively enrolled at a single institution. The distributions in the XT types were compared according to the D/N difference between primary and recurrent XT.
  
  
  RESULTS
  Preoperatively, the population comprised 14 divergence excess (DE) types and 107 basic types. After the BLR recession, the XT-type composition changed to 59 basic types, 33 CI types, and 29 DE types. In one of the 14 preoperatively identified DE-type XT cases, the XT type changed to CI type, it changed to basic type in four cases, and the remaining nine cases showed no change in the DE type. The 107 preoperatively identified basic-type XT cases postoperatively became 55 basic-type, 32 CI-type, and 20 DE-type recurrent XT cases, and their postoperative distance XT control grades and near stereoacuity values did not significantly differ.
  
  
  CONCLUSIONS
  The XT type composition changed after the BLR recession. The XT types in recurrent XT after BLR recession showed an increasing proportion of CI-type. We suspect that an individual fusion mechanism might also influence the XT-type in recurrent XT in view of the somewhat increased DE-type in recurrent XT.
authors.affiliation: Department of Ophthalmology, Hallym University College of Medicine, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang, Gyeonggi-do, 431-070, South Korea.|Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors.forename: Kwan Hyuk
authors.initials: KH
authors.lastname: Cho
authors.affiliation: Department of Ophthalmology, Hallym University College of Medicine, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang, Gyeonggi-do, 431-070, South Korea.
authors.forename: Hee Weon
authors.initials: HW
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Hallym University College of Medicine, Kangnam Sacred Heart Hospital, Seoul, South Korea.
authors.forename: Dong Gyu
authors.initials: DG
authors.lastname: Choi
authors.affiliation: Department of Ophthalmology, Hallym University College of Medicine, Hallym University Sacred Heart Hospital, 896 Pyeongchon-dong, Dongan-gu, Anyang, Gyeonggi-do, 431-070, South Korea. kimleejy@hallym.or.kr.
authors.forename: Joo Yeon
authors.initials: JY
authors.lastname: Lee
mesh_terms: D002648:Child; D002675:Child, Preschool; D003290:Convergence, Ocular / Q000502:physiology; D005099:Exotropia / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D009801:Oculomotor Muscles / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures; D012008:Recurrence; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology
keywords: Bilateral rectus recession; Distance-near difference; Exotropia type; Recurrent exotropia