title: [Comparison of hang-back medial rectus recession with conventional recession for the correction of esotropia in children].
abstract: BACKGROUND
  Extraocular muscles can be weakened by means of a conventional recession, or by means of a hang-back recession. This study compared the results of these techniques, their dose-response curves as well as intra- and postoperative complications for the correction of childhood esotropia.
  
  
  METHODS
  Healthy children with esotropia who received a medial rectus recession were included in this retrospective study. The recession was either performed as a conventional recession by direct scleral fixation, or as a hang-back recession. Ocular alignment (at distance fixation, 5 m and near fixation, 30 cm) as well as motility were compared preoperatively, and at 1 day and 3 months postoperatively. Dose-response curves and complication rates were compared.
  
  
  RESULTS
  Seventy-four children from 2 to 17 years were enrolled. Forty-four children received a conventional medial rectus recession, thirty received a hang-back recession. Preoperatively, average esotropia was 33.5 ± 16.03 prism diopters (PD) at distance in the conventional group and 40.93 ± 18.02 PD in the hang-back group. At near, it was 38.73 ± 16.22 PD and + 45.93 ± 17.6 PD, respectively. Three months postoperatively, average distance esotropia was 6.41 ± 12.32 PD in the conventional group and 6.19 ± 10 PD in the hang-back group, average near esotropia was + 7.43 ± 12.10 PD in the conventional group and + 9.00 ± 11.78 PD in the hang-back group. On average, one millimeter of medial rectus recession corrected 3.01 ± 1.34 PD of distance esotropia und 3.57 ± 1.3 PD of near esotropia in the conventional group, and 3.26 ± 1.07 PD and 3.53 ± 1.15 PD in the hang-back group, respectively. This difference was not statistically significant (Mann-Whitney-U-Test, p > 0.05). Complications such as scleral perforation, slipped or lost muscles and induced vertical strabismus were not observed.
  
  
  CONCLUSIONS
  Hang-back recession is an effective and safe alternative to conventional recession for the correction of esotropia in children. Larger prospective studies comparing long-term results of both techniques would be desirable.
authors.affiliation: Augenklinik, Universitätsklinikum Hamburg-Eppendorf.
authors.forename: S
authors.initials: S
authors.lastname: Heede
authors.affiliation: Augenklinik, Universitätsmedizin Berlin, Campus Virchow-Klinikum.
authors.forename: D
authors.initials: D
authors.lastname: Salchow
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004948:Esotropia / Q000175:diagnosis* / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures / Q000379:methods*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012590:Sclera / Q000601:surgery*; D058971:Tenotomy / Q000379:methods*; D016896:Treatment Outcome