title: Changes in detection of retinopathy in type 2 diabetes in the first 4 years of a population-based diabetic eye screening program: retrospective cohort study.
abstract: OBJECTIVE
  Annual diabetic eye screening has been implemented in England since 2008. This study aimed to estimate changes in the detection of retinopathy in the first 4 years of the program.
  
  
  METHODS
  Participants included 32,340 patients with type 2 diabetes resident in three London boroughs with one or more screening records between 2008 and 2011. Data for 87,570 digital images from 2008 to 2011 were analyzed. Frequency of sight-threatening diabetic retinopathy (STDR) was estimated by year of screen for first screens and for subsequent screens according to retinopathy status at first screen.
  
  
  RESULTS
  Among 16,621 first-ever screens, the frequency of STDR was 7.1% in 2008, declining to 6.4% in 2011 (P = 0.087). The proportion with a duration of diabetes of <1 year at first screen increased from 18.7% in 2008 to 48.6% in 2011. Second or later screens were received by 26,308 participants. In participants with mild nonproliferative retinopathy at first screen, the proportion with STDR at second or later screen declined from 21.6% in 2008 to 8.4% in 2011 (annual change -2.2% [95% CI -3.3 to -1.0], P < 0.001). In participants with no retinopathy at first screen, STDR declined from 9.2% in 2008 to 3.2% in 2011 (annual change -1.8% [-2.0 to -1.7], P < 0.001). Declining trends were similar in sociodemographic subgroups.
  
  
  CONCLUSIONS
  After the inception of population-based diabetic eye screening, patients at lower risk of STDR contribute an increasing proportion to the eligible population, and the proportion detected with STDR at second or subsequent screening rounds declines rapidly.
authors.affiliation: Department of Primary Care and Public Health Sciences, King's College London, London, UK. alice.s.forster@kcl.ac.uk
authors.forename: Alice S
authors.initials: AS
authors.lastname: Forster
authors.forename: Angus
authors.initials: A
authors.lastname: Forbes
authors.forename: Hiten
authors.initials: H
authors.lastname: Dodhia
authors.forename: Clare
authors.initials: C
authors.lastname: Connor
authors.forename: Alain
authors.initials: A
authors.lastname: Du Chemin
authors.forename: Sobha
authors.initials: S
authors.lastname: Sivaprasad
authors.forename: Samantha
authors.initials: S
authors.lastname: Mann
authors.forename: Martin C
authors.initials: MC
authors.lastname: Gulliford
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D012189:Retrospective Studies