title: Incidence of retinal complications in a cohort of newly diagnosed diabetic patients.
abstract: OBJECTIVE
  We aimed at estimating the incidence of diabetic retinopathy (DR) and maculopathy (DMP) among newly diagnosed type 1 (t1DM) and type 2 diabetic patients (t2DM) in the United Kingdom primary care system. The incidence of DMP among patients with DR was also estimated.
  
  
  METHODS
  We conducted a cohort study using The Health Improvement Network database. The cohort included 64,983 incident diabetic patients (97.3% were t2DM) aged 1-84 years diagnosed between 2000 and 2007. This cohort was followed from the date of diabetes diagnosis until recording of DR or DMP in two separate follow-ups. Follow-up was censored at 85 years of age, death, or end of 2008. An additional follow-up was conducted from DR to DMP diagnosis using similar censoring reasons. DR and DMP cumulative incidences were calculated as well as incidence rates (IR; cases per 1,000 person-years) per calendar period (2000-2001 and 2006-2007).
  
  
  RESULTS
  Follow-up for DR: 9 years after diabetes diagnosis, 28% of t2DM and 24% of t1DM patients had developed DR (7,899 incident DR cases). During the first 2 years with diabetes, the IR was almost 2 times higher in patients diagnosed with diabetes in 2006-2007 (47.7) than among those diagnosed in 2000-2001 (24.5). Follow-up for DMP: 9 years after diabetes diagnosis, 3.6% of t2DM and 4.4% of t2DM patients had developed DMP (912 incident DMP cases). During the first 2 years with diabetes, the IR was three times higher in patients diagnosed with diabetes in 2006-2007 (5.8) than among those diagnosed in 2000-2001 (1.8). Macular oedema occurred in 0.8% of patients.
  
  
  CONCLUSIONS
  In a cohort of incident diabetes, 28% of patients developed retinopathy and 4% maculopathy within the first 9 years. The 2-year IRs of DR and DMP were higher in patients diagnosed with diabetes during the period 2006-2007 than in those diagnosed during the 2000-2001 period.
authors: Centro Español de Investigación Farmacoepidemiológica, Madrid, Spain.
authors: Elisa
authors: E
authors: Martín-Merino
authors: DS&E - Global Clinical Epidemiology, Novartis Farmaceutica S.A., Barcelona, Spain.
authors: Joan
authors: J
authors: Fortuny
authors: DS&E - Global Clinical Epidemiology, Novartis Farmaceutica S.A., Barcelona, Spain.
authors: Elena
authors: E
authors: Rivero-Ferrer
authors: Centro Español de Investigación Farmacoepidemiológica, Madrid, Spain.
authors: Luis Alberto
authors: LA
authors: García-Rodríguez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000175:diagnosis*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000175:diagnosis*; D003930:Diabetic Retinopathy / Q000150:complications / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D008875:Middle Aged; D055815:Young Adult