title: The relationship between retinal vessel calibre and knee cartilage and BMLs.
abstract: BACKGROUND
  Whether the increase in vascular disease prevalence and mortality in OA populations is a result of co-occurrence of cardiovascular disease and OA, which are both common in the older population, is due to OA treatments or to the common association with reduced physical activity and/or obesity is unclear. One way to explore this non-invasively is to examine the cross-sectional relationship between changes in retinal microvasculature, which have been shown to be markers of generalized vascular pathology, and knee structural changes in an asymptomatic community-based population.
  
  
  METHODS
  A community sample of 289 (61% women) aged 50-79 years with no knee symptoms underwent magnetic resonance imaging (MRI) of their dominant knee in 2003. Cartilage volume and bone marrow lesions (BMLs) were determined. All subjects also had retinal photographs taken from which retinal arteriolar and venular diameters were determined and summarized as the central retinal arteriolar equivalent (CRAE) and the central retinal venular equivalent (CRVE).
  
  
  RESULTS
  Retinal venular diameter was significantly wider in subjects with a BML compared with subjects without a BML (mean (SD) 214.2 (2.8) μm versus 207.5 (1.1) μm respectively independent of age, gender and BMI. A trend for decreased medial tibial cartilage with increasing CRAE was also observed (regression coefficient -2.70 μl, 95%CI-5.74, 0.5, p=0.08).
  
  
  CONCLUSIONS
  These findings suggest that vascular pathology, indicative of inflammatory processes, is associated with early structural knee changes. The role of micro-vascular changes in the pathogenesis of OA warrants further investigation.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Central and Eastern Clinical School, Alfred Hospital, Melbourne, VIC, 3004, Australia.
authors.forename: Miranda L
authors.initials: ML
authors.lastname: Davies-Tuck
authors.forename: Ryo
authors.initials: R
authors.lastname: Kawasaki
authors.forename: Anita E
authors.initials: AE
authors.lastname: Wluka
authors.forename: Tien Y
authors.initials: TY
authors.lastname: Wong
authors.forename: Lauren
authors.initials: L
authors.lastname: Hodgson
authors.forename: Dallas R
authors.initials: DR
authors.lastname: English
authors.forename: Graham G
authors.initials: GG
authors.lastname: Giles
authors.forename: Flavia
authors.initials: F
authors.lastname: Cicuttini
mesh_terms: D000368:Aged; D001160:Arterioles / Q000473:pathology; D001853:Bone Marrow / Q000473:pathology*; D002358:Cartilage, Articular / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000276:immunology / Q000473:pathology*; D011237:Predictive Value of Tests; D031300:Retinal Vasculitis / Q000276:immunology / Q000473:pathology*; D012171:Retinal Vessels / Q000473:pathology*; D014699:Venules / Q000473:pathology