title: Retinal vascular calibre, geometry and progression of diabetic retinopathy in type 2 diabetes mellitus.
abstract: OBJECTIVE
  To determine whether changes in retinal vascular calibre and geometry are associated with progression of diabetic retinopathy in type 2 diabetes (T2D).
  
  
  METHODS
  The retinal vascular calibre and geometry of 30 subjects with more than 20 years of diagnosed T2D with no retinopathy (NR) were compared to 30 subjects that progressed to proliferative diabetic retinopathy (PDR). The images of PDR subjects included in this study were those obtained before the onset of retinopathy. The diameter of retinal arterioles (CRAE), retinal venules (CRVE), tortuosity of retinal vessels, junctional exponent deviation (JE(a)) and fractal dimension (D(f)) were measured using Singapore I Vessel Assessment (SIVA 3.0) software and compared using Mann-Whitney U test.
  
  
  RESULTS
  The median CRAE and the median CRVE were significantly wider in PDR subjects compared to NR subjects (p = 0.014 and 0.016), respectively. Curvature tortuosity of the retinal arteries and veins and D(f) were significantly decreased in the PDR subjects compared to NR subjects (p = 0.015, 0.016 and 0.03, respectively). The JE(a) was significantly increased in PDR subjects (p = 0.01).
  
  
  CONCLUSIONS
  Retinal vessel calibre and geometry of the retinal vasculature may be important risk factors for the progression to PDR. More longitudinal prospective studies will be needed to further explore the findings of this study.
authors.affiliation: King's College London, London, UK. roxanne.crosby-nwaobi @ kcl.ac.uk
authors.forename: Roxanne
authors.initials: R
authors.lastname: Crosby-Nwaobi
authors.forename: Ling Zhi
authors.initials: LZ
authors.lastname: Heng
authors.forename: Sobha
authors.initials: S
authors.lastname: Sivaprasad
mesh_terms: D001160:Arterioles / Q000473:pathology; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D010781:Photography; D012161:Retinal Artery / Q000473:pathology*; D012169:Retinal Vein / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors; D014699:Venules / Q000473:pathology