title: Evaluation of superior oblique weakening procedures.
abstract: OBJECTIVE
  To evaluate two superior oblique weakening procedures, silicon expander (SE), and translational recession (TR), and their effects on correction of "A" pattern, vertical deviation in adduction and dorsoadduction, superior oblique overaction, and torsion.
  
  
  METHODS
  In a prospective, institution-based study, 32 eyes of 16 patients having bilateral superior oblique overaction with significant "A" pattern (>10 prism diopters [delta]) were evaluated. The parameters studied were: change in "A" pattern; effect on vertical deviation in adduction and dorsoadduction; superior oblique overaction; and torsion. 95% reduction in "A" pattern with SE and 92% reduction with TR, indicating equal effect in collapse of "A" phenomenon (p=0.78). The extorsion produced by TR was more than that produced by SE (p=0.001).
  
  
  CONCLUSIONS
  Both the SE and TR procedures offered controlled weakening of the superior oblique and caused a 95% and 92% reduction in the "A" pattern. The latter procedure caused a marked extorsional change, three times that which resulted from SE. Both the procedures leave residual superior oblique overaction.
authors.affiliation: Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi.
authors.forename: P
authors.initials: P
authors.lastname: Sharma
authors.forename: S
authors.initials: S
authors.lastname: Khokhar
authors.lastname: Thanikachalam
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005133:Eye Movements; D005260:Female; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures / Q000592:standards*; D011446:Prospective Studies; D012826:Silicone Elastomers; D013285:Strabismus / Q000601:surgery*; D013710:Tendons / Q000601:surgery; D015625:Tissue Expansion Devices; D016896:Treatment Outcome
chemical_list: D012826:Silicone Elastomers