title: Parameters characterizing age-dependent retrobulbar circulation in healthy subjects measured by color Doppler ultrasonography.
abstract: OBJECTIVE
  The aim of this study was to analyze age-related effects influencing retrobulbar blood flow parameters.
  
  
  METHODS
  The study enrolled healthy volunteers (162 eyes) with a mean age of 49.64 years (SD ± 17.50). Participants were divided into 5 groups (G1-G5) based on 12-year age spans (means from 25.41 to 73.87 years). Peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV), pulsatility index (PI) and resistive index (RI) of the ophthalmic (OA), central retinal (CRA) and posterior ciliary arteries (PCAs) were measured by color Doppler ultrasonography (CDU). In addition, systemic blood pressure (BP), ocular perfusion pressure (OPP) and intraocular pressure (IOP) were evaluated. Statistical analysis was performed using the Shapiro-Wilk, Levene's, Spjotvoll-Stoline and analysis of variance tests (p ≤ 0.05 was considered statistically significant).
  
  
  RESULTS
  In the oldest group, significantly lower PSV, EDV in the CRA and PCAs as well as MV in the CRA were confirmed. Significantly increased RI in the OA, CRA and PCAs in regard to age was recorded.
  
  
  CONCLUSIONS
  CDU has considerable potential for evaluating hemodynamic changes in the retrobulbar circulation in relation to age. Age laboratory standards for a specific CDU device should be established for further analyses of blood flow in ocular diseases of vascular origin.
authors.affiliation: Department of Ophthalmology, Pomeranian Medical University , Szczecin , Poland .
authors.forename: Monika
authors.initials: M
authors.lastname: Modrzejewska
authors.forename: Brent
authors.initials: B
authors.lastname: Siesky
authors.forename: Annahita
authors.initials: A
authors.lastname: Amireskandari
authors.forename: Stephen
authors.initials: S
authors.lastname: Holland
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Grzesiak
authors.forename: Daniel
authors.initials: D
authors.lastname: Zaborski
authors.forename: Andrew
authors.initials: A
authors.lastname: Huck
authors.forename: Alon
authors.initials: A
authors.lastname: Harris
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D001775:Blood Circulation / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology; D019842:Ciliary Arteries / Q000502:physiology*; D005123:Eye / Q000098:blood supply*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009880:Ophthalmic Artery / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology*; D012161:Retinal Artery / Q000502:physiology*; D018615:Ultrasonography, Doppler, Color; D055815:Young Adult
keywords: Age effect; color Doppler ultrasonography; healthy volunteers; retrobulbar circulation; vascular changes