title: Congenital and infantile cataract in the United Kingdom: underlying or associated factors. British Congenital Cataract Interest Group.
abstract: OBJECTIVE
  Prevention of visual impairment and blindness in childhood due to congenital and infantile cataract is an important international goal. Preventive strategies require information about etiology that is currently unavailable for many regions of the world. From a national epidemiologic study, the underlying or associated factors in newly diagnosed cases of congenital or infantile cataract in the United Kingdom are reported, and the implications for future etiological research are discussed.
  
  
  METHODS
  All children with congenital or infantile cataract newly diagnosed during 1 year in the United Kingdom were ascertained independently through two national active surveillance schemes comprising ophthalmologists and pediatricians, respectively. Detailed information about cases, including disease causes, was collected from reporting clinicians using standard questionnaires.
  
  
  RESULTS
  Of 243 children with newly diagnosed congenital or infantile cataract, 160 (66%) had bilateral disease. Isolated cataract was more common in bilateral than unilateral cases (61% versus 47%, P = 0.05) as was cataract associated with a systemic disorder (25% versus 6%, P < 0.001). Conversely, cataract with associated ocular anomalies was more common in unilateral than bilateral cases (47% versus 14%, P < 0.001). No underlying or associated risk factors for cataract could be identified in 92% of unilateral and 38% of bilateral cases, although putative prenatal and perinatal risk factors were reported in a proportion of these idiopathic cases. Hereditary disease was associated with 56% of bilateral but only 6% of unilateral cases. Prenatal infections and other systemic factors were reported in only 6% of bilateral and 2% of unilateral cases.
  
  
  CONCLUSIONS
  Given the high proportion of idiopathic congenital and infantile cataract, the scope for primary prevention in the United Kingdom is currently limited. There is a need for further etiological research, to examine the roles of environmental and genetic risk factors for idiopathic cataract.
authors.affiliation: Department of Epidemiology, Institute of Child Health and Great Ormond Street Hospital, London, United Kingdom. j.rahi@ich.ucl.ac.uk
authors.forename: J S
authors.initials: JS
authors.lastname: Rahi
authors.forename: C
authors.initials: C
authors.lastname: Dezateux
mesh_terms: D000293:Adolescent; D002386:Cataract / Q000151:congenital* / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011159:Population Surveillance; D012307:Risk Factors; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology