title: Decline in the cumulative incidence of severe diabetic retinopathy in patients with type 1 diabetes.
abstract: OBJECTIVE
  To determine if the cumulative incidence of severe retinopathy in patients with type 1 diabetes has changed.
  
  
  METHODS
  The study looked at 3,781 patients diagnosed with type 1 diabetes (1939-2005), median age at onset 13 (interquartile range [IQR] 9-21) years, and duration of diabetes 19 (IQR 13-27) years. The severe retinopathy was based on a history of laser treatment. Patients were divided into <1975, 1975-1979, 1980-1984, and ≥1985 cohorts according to the diagnosis of diabetes.
  
  
  RESULTS
  The cumulative incidence of severe retinopathy has declined (P < 0.0001). After 20 years of duration, the cumulative incidence was 23% (95% CI 21-25) and 33 (30-35) in the earliest cohorts, 18 (15-21) in the next cohort, and 6 (4-9) in the recent cohort. After 30 years, the cumulative incidence was 52 and 48% in the earliest cohorts, while it was 62% after 40 years in the earliest cohort.
  
  
  CONCLUSIONS
  The cumulative incidence of severe retinopathy has declined in patients with type 1 diabetes.
authors.affiliation: Department of Ophthalmology, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Janne P
authors.initials: JP
authors.lastname: Kytö
authors.forename: Valma
authors.initials: V
authors.lastname: Harjutsalo
authors.forename: Carol
authors.initials: C
authors.lastname: Forsblom
authors.forename: Kustaa
authors.initials: K
authors.lastname: Hietala
authors.forename: Paula A
authors.initials: PA
authors.lastname: Summanen
authors.forename: Per-Henrik
authors.initials: PH
authors.lastname: Groop
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000453:epidemiology*; D003930:Diabetic Retinopathy / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D055815:Young Adult