title: Prevalence of systemic and ocular disease in infantile exotropia: comparison with infantile esotropia.
abstract: OBJECTIVE
  Exotropia in infancy is believed to be associated with an increased prevalence of neurologic, ocular, and craniofacial abnormalities; however, the prevalence of coexisting ocular and systemic disease in these patients is unknown. In this study, the prevalence of ocular disease and systemic illness was determined in patients diagnosed with exotropia in infancy.
  
  
  METHODS
  Observational comparative case series.
  
  
  METHODS
  Medical records of 70 patients diagnosed with exotropia in the first year of life were reviewed and compared with records of 136 patients diagnosed with esotropia before 1 year of age.
  
  
  METHODS
  Patients with no disorders (other than latent nystagmus, dissociated vertical deviation, or oblique muscle overaction) were grouped as "simple" strabismus. Patients with systemic disorders (including prematurity, neurologic disease, and genetic disease) and patients with ocular disorders (including congenital nystagmus, other strabismus, ptosis, and any condition associated with loss of vision [except amblyopia]) were grouped as "complex" strabismus.
  
  
  METHODS
  Prevalence of coexisting systemic and ocular disorders. The demographics, strabismus measurements, and types of coexisting disease in the simple and complex groups were compared.
  
  
  RESULTS
  A high percentage of both exotropia (67%) and esotropia (49%) patients had a coexisting ocular or systemic abnormality. Exotropia patients with a constant strabismus were more likely to have coexisting ocular or systemic disease than those with an intermittent strabismus. Smaller angles of exotropia or esotropia were associated with a higher likelihood of coexisting ocular or systemic diseases. Systemic disorders were found more frequently than ocular disorders in both the exotropia and esotropia groups. In 25% of all patients referred for evaluation of strabismus, an additional ocular or systemic abnormality was discovered by the ophthalmologist.
  
  
  CONCLUSIONS
  Patients presenting to a university hospital-based practice in the first year of life with exotropia were more likely than those presenting with esotropia to have coexisting ocular and systemic disease. Both groups had a notably high prevalence of associated disorders. The percentages measured in this population may not be applicable to other practices because of referral bias. However, clinicians should consider that children presenting with infantile exotropia and esotropia appear to be at risk for coexisting ocular or systemic disease.
authors.affiliation: The Zanvyl Krieger Children's Eye Center at the Wilmer Institute, Baltimore, Maryland, USA. dhunter@jhmi.edu
authors.forename: D G
authors.initials: DG
authors.lastname: Hunter
authors.forename: F J
authors.initials: FJ
authors.lastname: Ellis
mesh_terms: D015142:Baltimore / Q000453:epidemiology; D001763:Blepharoptosis / Q000150:complications* / Q000453:epidemiology; D019465:Craniofacial Abnormalities / Q000150:complications* / Q000453:epidemiology; D004948:Esotropia / Q000150:complications*; D005099:Exotropia / Q000150:complications*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009422:Nervous System Diseases / Q000150:complications* / Q000453:epidemiology; D009759:Nystagmus, Pathologic / Q000150:complications* / Q000151:congenital / Q000453:epidemiology; D015995:Prevalence