title: Prevalence of horizontal deviation pattern changes with measurements in extreme gazes.
abstract: OBJECTIVE
  To analyse the difference between measurement of A and V pattern strabismus at 25 degrees and extreme gaze position in esotropia (ET) and exotropia (XT).
  
  
  METHODS
  This prospective cross-section study included 27 patients with basic horizontal strabismus associated to any deviation pattern. Mean age was 11.88+/-9.17 (6-44) years. Exclusion criteria were amblyopia, intermittent XT, noncollaboration with the exam, previous strabismus surgery, craniofacial, or spinal abnormalities. The deviations were measured with prism cover test at 6 m. Measurements were carried out in primary position, upgaze (neck flexion of 25 degrees and maximum flexion) and downgaze (neck extension of 25 degrees and maximum extension). A goniometer with a bubble level controlled the neck position.
  
  
  RESULTS
  The most significant changes were in downgaze. The pattern size increased 4 prism dioptres (PD) or more in 56.25% of the V- and in 87.5% of the A-patterns. The mean increase was 8.00+/-6.04 PD (0-17 PD) for the A-pattern ET, 4.80+/-3.70 PD (0-10 PD) for the V-pattern XT, and 6.50+/-5.58 PD (0-15 PD) for the V-pattern XT. The only case of A-pattern XT increased 8 PD.
  
  
  CONCLUSIONS
  Our results suggest that measurements in extreme up and downgazes may uncover increased deviations in a significant proportion of cases. Further studies remain necessary to determine the relevance of these findings for strabismus correction.
authors.affiliation: Department of Strabismus, Universidade Federal do Rio Grande do Sul, Rio Grande do Sul, Brazil. eprocianoy@ terra.com.br
authors.forename: E
authors.initials: E
authors.lastname: Procianoy
authors.forename: L
authors.initials: L
authors.lastname: Procianoy
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003430:Cross-Sectional Studies; D004948:Esotropia / Q000503:physiopathology*; D005099:Exotropia / Q000503:physiopathology*; D005133:Eye Movements; D005260:Female; D019416:Head Movements; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000503:physiopathology*; D011446:Prospective Studies