title: Early screening for amblyogenic risk factors lowers the prevalence and severity of amblyopia.
abstract: OBJECTIVE
  To evaluate the efficacy of a mass screening program for amblyopia and amblyogenic risk factors in infants.
  
  
  METHODS
  Since 1968, children between the ages of 1 and 2(1/2) years in the city of Haifa, Israel, have been systematically screened for amblyopia and amblyogenic risk factors. The screening is performed by the Ophthalmology Department of Bnai-Zion Medical Center (formerly known as Rothchild Hospital). In 1995, we compared the prevalence and severity of amblyopia in two populations of 8-year-old children in elementary school: one group was a cohort of 808 children from the city of Haifa and its vicinity, who had been screened in infancy (between 1988 and 1990); and the second group, the control group, was a cohort of 782 children from Hadera and its vicinity, where this early screening program is not conducted. Amblyopia was defined as corrected visual acuity of < or =5/10 (20/40), or >1 line difference in corrected visual acuity between the two eyes. Referral rate, treatment rate, sensitivity, specificity, and positive predictive value and negative predictive value of the screening test in detecting factors that later resulted in the development of amblyopia were examined.
  
  
  RESULTS
  The prevalence of amblyopia in the 8-year-old population screened in infancy was found to be 1.0% compared with 2.6% in the 8-year-old population that had not been screened in infancy (P =.0098). The prevalence of amblyopia with visual acuity of < or =5/15 (20/60) in the amblyopic eye was 0.1% in the screened population compared with 1.7% in the non-screened population (P =.00026). In the screened infant population, 3.6% were referred from the screening examination to a confirmatory examination and 2.2% were treated. The screening examination had a sensitivity of 85.7% and a specificity of 98.6% for amblyopia. The positive predictive value of the screening examination was 62.1% and the negative predictive value was 99.6%.
  
  
  CONCLUSIONS
  The screening program for amblyopia and amblyogenic risk factors in infants, followed by appropriate treatment, is effective in significantly reducing the prevalence and severity of amblyopia in children.
authors.affiliation: Department of Ophthalmology, Kellogg Eye Center, University of Michigan, Ann Arbor 48105, USA. mayae@umich.edu
authors.forename: M
authors.initials: M
authors.lastname: Eibschitz-Tsimhoni
authors.forename: T
authors.initials: T
authors.lastname: Friedman
authors.forename: J
authors.initials: J
authors.lastname: Naor
authors.forename: N
authors.initials: N
authors.lastname: Eibschitz
authors.forename: Z
authors.initials: Z
authors.lastname: Friedman
mesh_terms: D000550:Amblyopia / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D015995:Prevalence; D012029:Refraction, Ocular; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013997:Time Factors; D015351:Vision Screening; D014792:Visual Acuity