title: Availability and variability in guidelines on diabetic retinopathy screening in Asian countries.
abstract: Diabetic retinopathy (DR) is a blinding yet treatable complication of diabetes. DR screening is highly cost-effective at reducing blindness. Amidst the rapidly growing diabetic population in Asia, the prevalence of DR in the region is relatively less well known.
  
  
  
  To review existing national DR screening guidelines of 50 countries in Asia, compare them against the International Council of Ophthalmology (ICO) guideline, and summarise the prevalence rates of DR and sight-threatening DR (STDR) in these countries.
  
  
  
  We systematically searched for published guidelines from the National Guideline Clearinghouse and other databases, and contacted local diabetic and ophthalmological associations of all 50 Asian countries.
  
  
  
  Eleven Asian countries have published relevant guidelines, nine of which pertain to general diabetes care and two are DR-specific, covering less than half of Asia's population. The median DR prevalence among patients with diabetes is 30.5% (IQR: 23.2%-36.8%), similar to the USA and the UK. However, rates of STDR are consistently higher. All guidelines from the 11 Asian countries fulfil the ICO standard on when to start and repeat screening, except for screening interval for pregnant patients. However, only 2 of the 11 guidelines fulfil the ICO referral criteria and 6 partially fulfil. A third of the recommendations on screening process, equipment and personnel is either unavailable or incomplete.
  
  
  
  Countries in Asia need to establish more comprehensive and evidence-based DR screening guidelines to facilitate the execution of robust screening programmes that could help reduce DR-related blindness, improve patient outcomes and reduce healthcare costs.
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Louis Zizhao
authors.initials: LZ
authors.lastname: Wang
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, Hong Kong.
authors.forename: Carol Y
authors.initials: CY
authors.lastname: Cheung
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Department of Optometry and Vision Sciences, The University of Melbourne, Melbourne, Victoria, Australia.|School of Clinical and Applied Sciences, Leeds Beckett University, Leeds, UK.
authors.forename: Robyn J
authors.initials: RJ
authors.lastname: Tapp
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
authors.forename: Haslina
authors.initials: H
authors.lastname: Hamzah
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
authors.forename: Gavin
authors.initials: G
authors.lastname: Tan
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.
authors.forename: Daniel
authors.initials: D
authors.lastname: Ting
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Duke-NUS Medical School, National University of Singapore, Singapore, Singapore.
authors.forename: Ecosse
authors.initials: E
authors.lastname: Lamoureux
authors.affiliation: Singapore Eye Research Institute, Singapore National Eye Centre, Singapore, Singapore.|Duke-NUS Medical School, National University of Singapore, Singapore, Singapore.
authors.forename: Tien Yin
authors.initials: TY
authors.lastname: Wong
mesh_terms: D001208:Asia / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003930:Diabetic Retinopathy / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D008403:Mass Screening / Q000592:standards*; D010781:Photography; D017410:Practice Guidelines as Topic / Q000592:standards*; D015995:Prevalence; D012307:Risk Factors
keywords: Epidemiology; Retina