title: Correlation of postoperative extraocular muscle suture adjustment with its immediate effect on the strabismic deviation.
abstract: OBJECTIVE
  To determine if any relationship exists between the amount of adjustment using this surgical technique and resulting changes in the strabismic deviation.
  
  
  METHODS
  A prospective database obtained between the years 1991 and 1996 was used to obtain retrospective clinical information and data for this study. We found in the database 172 postoperatively adjusted muscles in 159 patients who could be included in this study. All patients had their muscles adjusted postoperatively within the first 24 hours after surgery. Information retrieved specific to this study included the post-surgical, pre-adjustment strabismic deviation, the amount and direction of the adjustment and the resulting deviation immediately after this postoperative adjustment. Statistical analysis was performed on the total and individual muscles, as well as the direction of adjustment, comparing pre- to post-adjustment binocular deviations.
  
  
  RESULTS
  There was a significant overall relationship between the millimeters of postoperative adjustment and the amount of change in the binocular deviation (p<.0001). This relationship was more linear under 3.0 mm of postoperative adjustment. The effect of the amount of postop' adjustment when advancing the muscle was significantly greater than when recessing the muscle (p<.0001). There was more effect per mm of postop' adjustment of horizontal muscles than vertical muscles (p=.004).
  
  
  CONCLUSIONS
  There is a linear correlation of postoperative extraocular muscle adjustment when advancing an adjustable muscle but this correlation is more variable for adjustments over 3.0 mm. The effect of adjustment per mm is greater when adjusting horizontal than vertical muscles. There is a poor correlation for further recession. Prediction Equations are provided to enhance clinical results of this technique.
authors.affiliation: Laboratory of Sensorimotor Research, The National Eye Institute, The National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Bacal
authors.forename: R W
authors.initials: RW
authors.lastname: Hertle
authors.forename: M G
authors.initials: MG
authors.lastname: Maguire
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009801:Oculomotor Muscles / Q000503:physiopathology / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures; D011182:Postoperative Care / Q000379:methods; D011446:Prospective Studies; D012189:Retrospective Studies; D013285:Strabismus / Q000503:physiopathology / Q000601:surgery*; D013536:Suture Techniques; D015348:Vision, Binocular / Q000502:physiology