title: Why do patients still require surgery for the late complications of Proliferative Diabetic Retinopathy?
abstract: OBJECTIVE
  To briefly review and discuss the literature on why patients still require surgery for the late complications of proliferative diabetic retinopathy (PDR).
  
  
  METHODS
  Literature review.
  
  
  RESULTS
  The reasons for incomplete coverage of screening and screening failures can be divided into non-modifiable and potentially modifiable risk factors. The non-modifiable group includes duration of diabetes, age, genetic predisposition, ethnic differences, and the various reasons for vitrectomy when optimum laser treatment has been applied at the appropriate stage of the disease process. The potentially modifiable group includes glycaemic control, blood pressure control, lipid control, and cessation of smoking in type 1 diabetes. Other potentially modifiable factors include adequacy of screening, including reaching the regular non-attender, and attempting to modify the psychological factors that lead to late presentations including depression and eating disorders. Other potentially modifiable risk factors are optimising laser treatments and the potential use of anti-VEGF therapy to prevent vitrectomy in iris neovascularisation and neovascular glaucoma.
  
  
  CONCLUSIONS
  Surgery for the late complications of PDR continues to be required even in some patients who have received optimal medical care and optimal laser treatment. There are certain modifiable risk factors that could be altered and further research is needed in specific fields, particularly with regard to the adequacy of laser treatments, the use of anti-VEGF agents in iris neovascularisation, and in the role of psychological support in reducing the type of late complications leading to surgery for PDR.
authors.affiliation: Gloucestershire Eye Unit, Cheltenham General Hospital, Cheltenham, UK. peter.scanlon@glos.nhs.uk
authors.forename: P H
authors.initials: PH
authors.lastname: Scanlon
mesh_terms: D000367:Age Factors; D020533:Angiogenesis Inhibitors / Q000627:therapeutic use; D003930:Diabetic Retinopathy / Q000150:complications* / Q000235:genetics / Q000601:surgery* / Q000628:therapy; D020022:Genetic Predisposition to Disease; D005901:Glaucoma / Q000601:surgery; D006801:Humans; D017075:Laser Coagulation / Q000592:standards; D008403:Mass Screening / Q000592:standards; D009389:Neovascularization, Pathologic / Q000517:prevention & control / Q000601:surgery; D012307:Risk Factors; D014821:Vitrectomy
chemical_list: D020533:Angiogenesis Inhibitors