title: The remnants of crossed fixation observed in teenaged children with esotropia.
abstract: OBJECTIVE
  To report 2 cases of teenage children with esotropia from a much earlier age, displaying remnants of crossed fixation with special reference to Helmholtz's theory that each eye is controlled independently and Hering's Law of equal innervation.
  
  
  METHODS
  Case 1 had paretic and partially accommodative esotropia that was first observed at 11 months of age; and Case 2 had accommodative esotropia with an onset at age 3 years. Both cases had hypermetropia and good corrected visual acuity in both eyes. They were able to fixate independently with each eye but the dominant eye always controls their fixation and they believe they are using only their dominant eye; however, their non-dominant eye was used to viewing objects in the opposite field (crossed fixation). Both cases maintained good binocular alignment at distance with either surgery and glasses (Case 1) or glasses alone (Case 2). However, their esotropia increased through the early teenage years leading both patients to undergo surgery at this later age: Case 1 at 17 years of age and Case 2 at 19 years of age. Post-surgical Starlight testing showed that their binocular visual fields improved.
  
  
  CONCLUSIONS
  Crossed fixation exists in esotropia (even in acquired accommodative esotropia) and as the patient ages, one eye becomes dominant leaving the non-dominant eye to fix only in crossed gaze. These cases support Helmholtz's theory that each eye is controlled independently and that binocular coordination is learned.
authors.affiliation: Department of Ophthalmology, Nagoya University School of Medicine, Japan. hraito@asu.aasa.ac.jp
authors.forename: Toshie
authors.initials: T
authors.lastname: Hirai
authors.forename: Emi
authors.initials: E
authors.lastname: Amano
authors.forename: Teruko
authors.initials: T
authors.lastname: Ito
authors.forename: Kinichi
authors.initials: K
authors.lastname: Tsuzuki
authors.forename: Miho
authors.initials: M
authors.lastname: Sato
authors.forename: Yozo
authors.initials: Y
authors.lastname: Miyake
mesh_terms: D000065:Accommodation, Ocular; D000293:Adolescent; D000328:Adult; D004948:Esotropia / Q000175:diagnosis* / Q000601:surgery; D005403:Fixation, Ocular; D006801:Humans; D008297:Male; D009801:Oculomotor Muscles / Q000601:surgery; D015348:Vision, Binocular / Q000502:physiology; D014794:Visual Fields / Q000502:physiology