title: Can the retinal screening interval be safely increased to 2 years for type 2 diabetic patients without retinopathy?
abstract: OBJECTIVE
  In the U.K., people with diabetes are typically screened for retinopathy annually. However, diabetic retinopathy sometimes has a slow progression rate. We developed a simulation model to predict the likely impact of screening patients with type 2 diabetes, who have not been diagnosed with diabetic retinopathy, every 2 years rather than annually. We aimed to assess whether or not such a policy would increase the proportion of patients who developed retinopathy-mediated vision loss compared with the current policy, along with the potential cost savings that could be achieved.
  
  
  METHODS
  We developed a model that simulates the progression of retinopathy in type 2 diabetic patients, and the screening of these patients, to predict rates of retinopathy-mediated vision loss. We populated the model with data obtained from a National Health Service Foundation Trust. We generated comparative 15-year forecasts to assess the differences between the current and proposed screening policies. RESULTS The simulation model predicts that implementing a 2-year screening interval for type 2 diabetic patients without evidence of diabetic retinopathy does not increase their risk of vision loss. Furthermore, we predict that this policy could reduce screening costs by ~25%.
  
  
  CONCLUSIONS
  Screening people with type 2 diabetes, who have not yet developed retinopathy, every 2 years, rather than annually, is a safe and cost-effective strategy. Our findings support those of other studies, and we therefore recommend a review of the current National Institute for Health and Clinical Excellence (NICE) guidelines for diabetic retinopathy screening implemented in the U.K.
authors.affiliation: Peninsula Collaboration for Health, Operational Research, and Development, University of Exeter, Exeter, Devon, UK daniel.chalk@pcmd.ac.uk
authors.forename: Daniel
authors.initials: D
authors.lastname: Chalk
authors.forename: Martin
authors.initials: M
authors.lastname: Pitt
authors.forename: Bijay
authors.initials: B
authors.lastname: Vaidya
authors.forename: Ken
authors.initials: K
authors.lastname: Stein
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D013997:Time Factors