title: Orbital colour Doppler imaging in chronic ocular ischaemic syndrome.
abstract: BACKGROUND
  The clinical syndrome of chronic ocular ischaemia may be difficult to diagnose due to its wide range of non-specific presentations, and its diagnosis often implies the presence of underlying severe carotid occlusive disease. Colour Doppler imaging (CDI), a recent advance in ultrasonography that allows for colour-encoded blood flow data of a vascular structure to be displayed simultaneously on a conventional real-time gray-scale B mode image, has been used in the assessment of ocular and orbital vasculature.
  
  
  METHODS
  Four patients with chronic ocular ischaemic syndrome whose diagnoses were aided by CDI are presented.
  
  
  RESULTS
  Orbital CDI was successful in confirming the diagnosis in all four cases. Reversal of blood flow in the ophthalmic arteries was demonstrated. Central retinal vessels were not detected with CDI in all four patients with complete occlusion of the ipsilateral internal carotid artery. One of the four patients had intermittent reversal of ophthalmic arterial flow ipsilateral to the 60% stenosed interna carotid artery.
  
  
  CONCLUSIONS
  This non-invasive technique is an excellent alternative to invasive vascular studies such as angiography for the diagnosis and evaluation of the chronic ocular ischaemic syndrome.
authors.affiliation: Eye Department, Tan Tock Seng Hospital, Singapore.
authors.forename: H M
authors.initials: HM
authors.lastname: Lee
authors.forename: E R
authors.initials: ER
authors.lastname: Fu
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D002339:Carotid Arteries / Q000000981:diagnostic imaging; D016893:Carotid Stenosis / Q000150:complications; D002908:Chronic Disease; D006801:Humans; D007511:Ischemia / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging*; D009915:Orbit / Q000098:blood supply* / Q000000981:diagnostic imaging; D013577:Syndrome; D018615:Ultrasonography, Doppler, Color