Parameters Characterizing Age-Dependent Retrobulbar Circulation in Healthy Subjects Measured by Color Doppler Ultrasonography

The aim of this study was to analyze age-related effects influencing retrobulbar blood flow parameters.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).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.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.