title: The association between retinal vascular geometry changes and diabetic retinopathy and their role in prediction of progression--an exploratory study.
abstract: BACKGROUND
  The study describes the relationship of retinal vascular geometry (RVG) to severity of diabetic retinopathy (DR), and its predictive role for subsequent development of proliferative diabetic retinopathy (PDR).
  
  
  METHODS
  The research project comprises of two stages. Firstly, a comparative study of diabetic patients with different grades of DR. (No DR: Minimal non-proliferative DR: Severe non-proliferative DR: PDR) (10:10: 12: 19). Analysed RVG features including vascular widths and branching angles were compared between patient cohorts. A preliminary statistical model for determination of the retinopathy grade of patients, using these features, is presented. Secondly, in a longitudinal predictive study, RVG features were analysed for diabetic patients with progressive DR over 7 years. RVG at baseline was examined to determine risk for subsequent PDR development.
  
  
  RESULTS
  In the comparative study, increased DR severity was associated with gradual vascular dilatation (p = 0.000), and widening of the bifurcating angle (p = 0.000) with increase in smaller-child-vessel branching angle (p = 0.027). Type 2 diabetes and increased diabetes duration were associated with increased vascular width (p = <0.05 In the predictive study, at baseline, reduced small-child vascular width (OR = 0.73 (95% CI 0.58-0.92)), was predictive of future progression to PDR.
  
  
  CONCLUSIONS
  The study findings suggest that RVG alterations can act as novel markers indicative of progression of DR severity and establishment of PDR. RVG may also have a potential predictive role in determining the risk of future retinopathy progression.
authors.affiliation: Sunderland Eye Infirmary - Queen Alexandra Road, Sunderland SR2 9HP, UK. maged.habib@chsft.nhs.uk.
authors.forename: Maged S
authors.initials: MS
authors.lastname: Habib
authors.forename: Bashir
authors.initials: B
authors.lastname: Al-Diri
authors.forename: Andrew
authors.initials: A
authors.lastname: Hunter
authors.forename: David H W
authors.initials: DH
authors.lastname: Steel
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003930:Diabetic Retinopathy / Q000175:diagnosis*; D003941:Diagnostic Techniques, Ophthalmological; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012372:ROC Curve; D012171:Retinal Vessels / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors