title: Orbital Doppler evaluation of blood flow velocities in optic neuritis.
abstract: OBJECTIVE
  To evaluate orbital blood flow velocities and optic nerve diameter with Doppler and gray-scale sonography in patients with acute unilateral optic neuritis (ON).
  
  
  METHODS
  Orbital Doppler and gray-scale sonography was performed in 46 eyes of 23 patients aged 19- to 47-years with acute unilateral ON. ON was diagnosed by an ophthalmologist on the basis of clinical presentation, presence of decreased visual acuity and assessment of visual evoked potentials. The peak systolic velocity (PSV) and end-diastolic velocity (EDV), as well as the resistance index (RI) and pulsatile index (PI) of the ophthalmic artery (OA), central retinal artery (CRA), posterior ciliary arteries (PCAs) and optic nerve diameter were measured in both eyes. We compared results from affected and unaffected eyes using the paired t-test. The area under the receiver operating characteristic (ROC) curves was used to assess the diagnosis of ON based on measured blood flow parameters of the OA, CRA and PCAs and optic nerve diameter.
  
  
  RESULTS
  The mean (standard deviation) optic nerve diameter in eyes with ON was 4.1 (0.8) mm, which was significantly larger than the 3.0 (0.4) mm diameter measured in unaffected control eyes (p < 0.001). There were no differences in average PSV, EDV, RI, or PI of the OA and CRA between affected and unaffected eyes (p > 0.05). The mean RI in the PCAs was slightly lower in the eyes with ON than in the contralateral eyes (0.60 vs. 0.64, p < 0.05). The area under the ROC curves indicated that optic nerve diameter was the best parameter for the diagnosis of ON.
  
  
  CONCLUSIONS
  Optic nerve diameter was related to ON, but orbital blood flow parameters were not.
authors.affiliation: Department of Radiology, Isfahan University of Medical Sciences School of Medicine, Isfahan, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Karami
authors.forename: Mohsen
authors.initials: M
authors.lastname: Janghorbani
authors.forename: Alireza
authors.initials: A
authors.lastname: Dehghani
authors.forename: Maryam
authors.initials: M
authors.lastname: Riahinejad
mesh_terms: D000328:Adult; D006801:Humans; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000000981:diagnostic imaging* / Q000502:physiology*; D009900:Optic Nerve / Q000098:blood supply* / Q000000981:diagnostic imaging*; D009902:Optic Neuritis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D009915:Orbit / Q000098:blood supply / Q000000981:diagnostic imaging; D011673:Pulsatile Flow / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D018615:Ultrasonography, Doppler, Color; D014655:Vascular Resistance / Q000502:physiology; D055815:Young Adult