title: Vascular network changes in the retina during ageing in normal subjects: a computerized quantitative analysis.
abstract: BACKGROUND
  Direct ophthalmoscopic examination of fundus oculi is widely used for the qualitative evaluation of target organ damage in several pathological conditions. At present, there are no reliable techniques available to quantify retinal vascular damage. The aim of this study was to develop a computerized technique for the quantitative analysis of fundus oculi.
  
  
  METHODS
  We studied 68 non-smoking, normotensive normal subjects, with a visual acuity > 8/10. From each subject retinal images were taken using a non-mydriatic ophthalmoscope and digitized onto a personal computer. In each image the area of analysis was set to a circular selection, corresponding to 25% of the whole fundus oculi, concentric with the optic disc. From each selection arterial and venous area and mean arteriolar bifurcation angle were obtained. Measurements were taken in a blinded way by two operators and, by the same operator, twice at different times. Parameters were correlated with age and body surface area.
  
  
  RESULTS
  Retinal arterial density (arteries 7.44 +/- 1.25%; bifurcation angle 75 +/- 16 degrees) was significantly correlated with age, but not with body surface area. Intra- and interobserver coefficient of variation resulted 2.5 and 3.2%, respectively.
  
  
  CONCLUSIONS
  Computerized analysis of the fundus oculi with the evaluation of vascular density indexes represents a simple and reproducible technique that could be useful in identifying changes in retinal vascular network during ageing.
authors.affiliation: Institute of Internal Medicine, Centro di Fisiologia Clinica e Ipertensione, Ospedale Maggiore Policlinico IRCCS, University of Milan, Italy. img.lab@mailserver.unimi.it
authors.forename: M M
authors.initials: MM
authors.lastname: Ciulla
authors.forename: G
authors.initials: G
authors.lastname: Tortora
authors.forename: P
authors.initials: P
authors.lastname: Valentini
authors.forename: R
authors.initials: R
authors.lastname: Paliotti
authors.forename: V
authors.initials: V
authors.lastname: Buonamici
authors.forename: A
authors.initials: A
authors.lastname: Moraschi
authors.forename: M V
authors.initials: MV
authors.lastname: Barelli
authors.forename: F
authors.initials: F
authors.lastname: Magrini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology*; D001830:Body Surface Area; D002648:Child; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009887:Ophthalmoscopy; D012016:Reference Values; D012161:Retinal Artery / Q000473:pathology*