title: Prevalence and causes of visual impairment in craniosynostotic syndromes.
abstract: BACKGROUND
  To assess the prevalence and causes of visual impairment in patients with craniosynostotic syndromes of Apert, Crouzon, Pfeiffer, Saethre-Chotzen and craniofrontonasal dysplasia.
  
  
  METHODS
  The medical records of patients who attended the Craniofacial Clinic at two large paediatric hospitals in Sydney, Australia between 1983 and 2004 were retrospectively reviewed. Presenting visual acuity (VA) was assessed using tests appropriate to age and cognition: 'fix and follow' in infants (<18 months old), Teller card acuity in preverbal children (18 months to less than 3 years old), Kay picture test or Sheridan-Gardiner test in children aged between 3 and less than 6 years and Snellen chart in those aged 6 years or older. Visual impairment was defined as the inability to fix and follow or presenting VA < 6/12 in the better eye. Amblyopia was defined as a two-line difference in VA between both eyes in the absence of an organic eye disease.
  
  
  RESULTS
  Sixty-three patients with craniosynostotic syndromes were identified, of whom 55 had VA assessed at the first visit. Of these 55, 19 (35.5%) had bilateral visual impairment and 5 (9.1%) had unilateral visual impairment. Causes of visual impairment include amblyopia (16.7%), ametropia (25%), optic atrophy (16.7%) and exposure keratopathy (4.2%). Risk factors for amblyopia include strabismus (43.3%), astigmatism (> or =1.5 dioptres) (39.5%), hypermetropia (18.4%) and anisometropia (> or =1.5 dioptre difference between both eyes) (15.8%). Six of the 63 patients (9.5%) had papilloedema; those who were followed up showed gradual resolution of papilloedema following timely decompressive surgery.
  
  
  CONCLUSIONS
  A high prevalence of visual impairment in patients with craniosynostotic syndromes was found, almost half of them due to potentially correctable causes, including amblyopia and ametropia. Optic atrophy remains an important cause of visual impairment. Further studies are needed to assess the timing and efficacy of intervention for modifiable causes of visual loss in craniosynostotic syndromes.
authors.affiliation: Department of Ophthalmology, The Children's Hospital at Westmead, Sydney, NSW, Australia.
authors.forename: Tien
authors.initials: T
authors.lastname: Tay
authors.forename: Frank
authors.initials: F
authors.lastname: Martin
authors.forename: Neil
authors.initials: N
authors.lastname: Rowe
authors.forename: Kim
authors.initials: K
authors.lastname: Johnson
authors.forename: Michael
authors.initials: M
authors.lastname: Poole
authors.forename: Kimberley
authors.initials: K
authors.lastname: Tan
authors.forename: Ian
authors.initials: I
authors.lastname: Kennedy
authors.forename: Mark
authors.initials: M
authors.lastname: Gianoutsos
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D003398:Craniosynostoses / Q000150:complications*; D005128:Eye Diseases / Q000150:complications; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009517:New South Wales / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013577:Syndrome; D014786:Vision Disorders / Q000453:epidemiology* / Q000209:etiology*; D014787:Vision Tests / Q000295:instrumentation / Q000379:methods; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*