title: Horizontal and vertical angle kappa.
abstract: BACKGROUND
  The aim of this study is to report the geometric range of angle kappa formation in patients with and without strabismus.
  
  
  METHODS
  This is a retrospective study of three patients with angle kappa in different planes. Routine eye examinations, including visual acuity, slit-lamp examination, and ophthalmoscopy, were performed. A thorough orthoptic examination revealed a notable difference between the prism and alternate-cover test and the Hirschberg measurements.
  
  
  RESULTS
  The first patient exhibited a bilateral vertical angle kappa into opposite directions due to retinochoroidal scars. Two other patients presented with horizontal angle kappa deviations. In one patient a true accommodative esotropia was exaggerated by a right negative angle kappa. The other patient had a pseudoexotropia due to bilateral positive angle kappa. Macular ectopia was noted in all cases.
  
  
  CONCLUSIONS
  The patients herein reported demonstrate a marked variability of angle kappa occurrence in the horizontal and vertical plane. The angle kappa can exaggerate or conceal the size of the true heterotropia.
authors.affiliation: Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children and the University of Toronto, Canada. veit.sturm@usz.ch
authors.forename: V
authors.initials: V
authors.lastname: Sturm
authors.forename: S P
authors.initials: SP
authors.lastname: Kraft
authors.forename: K
authors.initials: K
authors.lastname: Landau
mesh_terms: D000328:Adult; D002648:Child; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D008297:Male; D013285:Strabismus / Q000175:diagnosis* / Q000503:physiopathology*