title: Ascertainment of children with congenital cataract through the National Congenital Anomaly System in England and Wales.
abstract: OBJECTIVE
  Congenital ocular anomalies contribute significantly to childhood visual morbidity, with congenital cataract being a major cause of visual impairment throughout the world. As in many other countries, a National Congenital Anomaly System (NCAS) exists in England and Wales to monitor the frequency of ocular and other anomalies in order to identify new public health hazards and inform aetiological research. The aim of this study was to assess level of ascertainment by the NCAS of children with congenital cataract.
  
  
  METHODS
  Using independent ophthalmic and paediatric national active surveillance schemes, all infants (< or =1 year) newly diagnosed with congenital and infantile cataract in England and Wales in 1 year from September 1995 were identified. These notifications were compared with those made independently to the NCAS during the same period. The proportion of cases identified by the active surveillance schemes and also notified to the NCAS was determined.
  
  
  RESULTS
  10% (15/149) of eligible children with newly diagnosed congenital or infantile cataract were actually notified to the NCAS. A higher proportion of those diagnosed as neonates (16%, 14/85) than in later infancy (2%, 1/64) was ascertained through the NCAS. There is a need for better verification of notifications and reported information in the NCAS.
  
  
  CONCLUSIONS
  Currently, ascertainment of congenital cataract through the NCAS is low and the system is likely to be insensitive to small but important changes in risk factors for this disorder. This limits its use for monitoring secular and other trends in ocular anomalies. Strategies to improve its future use are discussed, including enhancing the awareness and participation of ophthalmic professionals involved in managing children with anomalies.
authors.affiliation: Department of Paediatric Epidemiology, Institute of Child Health, Great Ormond Street Hospital NHS Trust, London, UK. j.rahi@ich.ucl.ac.uk
authors.forename: J S
authors.initials: JS
authors.lastname: Rahi
authors.forename: B
authors.initials: B
authors.lastname: Botting
mesh_terms: D002386:Cataract / Q000151:congenital* / Q000453:epidemiology*; D004739:England / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D011446:Prospective Studies; D012042:Registries; D014852:Wales / Q000453:epidemiology