Abstract
Abstract: :
Purpose:The therapeutic benefit of hypervolemic hemodilution is based on a volume effect and an improvement of rheological factors like plasma viscosity and erythrocyte aggregation. To investigate the acute effect of hydroxyethyl starch on retrobulbar hemodynamics in patients with anterior ischemic optic neuropathy (AION). Methods:We examined 20 patients with AION (mean age 65 ± 9 years) before and 15 min after infusion of 250 cc 10% hydroxyethyl starch (molecular weight 200.000/ degree of substitution 0.5 within 30 min). Retrobulbar blood flow velocities (peak systolic velocity (PSV) and end–diastolic velocity (EDV)) and resistive indices (RI) of the ophthalmic artery (OA), the central retinal artery (CRA) and the temporal and nasal short posterior ciliary arteries (PCA) were measured by color Doppler imaging. Results:After infusion of hydroxyethyl starch PSV significantly increased in the CRA from 7.68 ± 2.43 to 8.49 ± 2.54 cm/sec (p=0.002) and in the PCA from 7.33 ± 1.61 to 7.65 ± 1.52 cm/sec (p=0.0032). EDV and RI in the CRA and PCA remained unaffected. The OA showed no changes in retrobulbar blood flow velocities and RI after hypervolemic hemodilution. Blood pressure and heart rate remained unchanged. Conclusions:Hypervolemic hemodilution has an acute effect on the peak systolic velocities in the CRA and the PCA and no influence on retrobulbar hemodynamics in the OA. Increased blood flow velocities in the arteries supplying the optic nerve head may lead to a better perfusion of the optic nerve head in patients with AION.
Keywords: blood supply • optic disc • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)