title: First diabetic retinopathy prevalence study in Portugal: RETINODIAB Study--evaluation of the screening programme for Lisbon and Tagus Valley region.
abstract: OBJECTIVE
  In Portugal, so far, there is no study or even accurate data on the prevalence of diabetic retinopathy (DR), based on a large representative sample and on a long-term follow-up. The objective of our study was to determine the prevalence of DR based on a national screening community-based programme.
  
  
  METHODS
  A 5-year retrospective analysis of the RETINODIAB screening programme results was implemented in Lisbon and Tagus Valley area between July 2009 and October 2014. We estimated the prevalence of retinopathy for all patients with type 2 diabetes and studied the association between known risk factors and retinopathy emergence at their first screening.
  
  
  RESULTS
  Throughout this period, from a total of 103 102 DR readable screening examinations, 52 739 corresponded to patients who attended RETINODIAB screening at entry. Globally, DR was detected in 8584 patients (16.3%). Of these, 5484 patients (10.4%) had mild non-proliferative (NP) DR, 1457 patients (2.8%) had moderate NPDR and 672 (1.3%) had severe NPDR. Finally, 971 patients (1.8%) had proliferative DR requiring urgent referral to an ophthalmologist. The presence of any DR, non-referable DR or referable DR was strongly associated with increasing duration of diabetes and earlier age at diagnosis.
  
  
  CONCLUSIONS
  The prevalence rate of DR in our study (16.3%) was slightly lower than other published international data. The RETINODIAB network proved to be an effective screening programme as it improved DR screening in Lisbon and Tagus Valley surrounding area.
authors.affiliation: Portuguese Diabetes Association APDP, Lisbon, Portugal Department of Ophthalmology, Central Lisbon Hospital Center, Lisbon, Portugal NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal.
authors.forename: Marco
authors.initials: M
authors.lastname: Dutra Medeiros
authors.affiliation: University of Minho, Braga, Portugal.
authors.forename: Edgar
authors.initials: E
authors.lastname: Mesquita
authors.affiliation: CEAUL, Lisbon, Portugal Statistics and Informatics Department, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal Epidemiology and Statistics Unit, Research Centre, Central Lisbon Hospital Center, Lisbon, Portugal.
authors.forename: Ana Luísa
authors.initials: AL
authors.lastname: Papoila
authors.affiliation: Portuguese Diabetes Association APDP, Lisbon, Portugal.
authors.forename: Victor
authors.initials: V
authors.lastname: Genro
authors.affiliation: Portuguese Diabetes Association APDP, Lisbon, Portugal Department of Public Health/CEDOC, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal.
authors.forename: João Filipe
authors.initials: JF
authors.lastname: Raposo
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003930:Diabetic Retinopathy / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011174:Portugal / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
keywords: Clinical Trial; Epidemiology; Macula; Retina; Treatment Lasers