AIM To present a new non-invasive method of performing a high definition topography of perfused vessels of the retina and the optic nerve head with simultaneous evaluation of blood flow. METHOD By a combination of a laser Doppler flowmeter with a scanning laser system the perfusion of the retina and the optic nerve head is visualised. The principles of measuring blood flow by laser Doppler fl...

The aim of the study was to determine whether the Heidelberg Retinal Flowmeter (HRF), a confocal scanning laser Doppler flowmeter, can measure choroidal blood flow in pig eyes.An HRF was used to obtain flow maps from in vitro pig eyes under a range of perfusion flow rates (0 - 500 microL/min) under conditions in which only the choroid was perfused. In some cases choroidal blood flow was also me...

Photoplethysmography (PPG) is a technique that permits noninvasive measurement of changes in the volume of tissues. A novel device uses PPG to assess changes in duodenal mucosal perfusion. When tested in septic piglets, data obtained using this device correlate with the blood lactate concentration and duodenal serosal microvascular blood flow as measured with a laser Doppler flowmeter. This new...

Cutaneous vasomotor reflexes (CVR), the transient waves of cutaneous vasoconstriction after stimuli, such as a cough, were recorded from the digits of patients with unilateral frontoparietal lesions using a laser doppler flowmeter. Vasoconstriction was 6-15 times greater on the fingers contralateral to the lesions, an effect which was independent of the temperature difference between limbs. CVR...

The laser Doppler flowmeter has been shown to give a response from the cochlea during high intensity acoustic stimulation which is not related to blood flow through the cochlea. The magnitude of this response depends upon the intensity and frequency of stimulation and the location of the probe on the cochlea. Evidence is presented that the response is derived from the vibration of cochlear tiss...

BACKGROUND Greater occipital nerve block is used in the treatment of headaches and neuralgia in the occipital area. We evaluated the efficacy of ultrasonic doppler flowmeter-guided occipital nerve block in patients experiencing headache in the occipital region in a randomized, prospective, placebo-controlled study. METHODS Twenty-six patients, aged 18 to 70, with headache in the occipital reg...

Impaired ocular blood flow is involved in the pathogenesis of numerous ocular diseases like glaucoma or AMD. The purpose of the present study was to introduce and validate a novel, microscope based, non-invasive Laser Doppler Flowmeter (NI-LDF) for measurement of blood flow in the choroid. The custom made NI-LDF was compared with a commercial fiber optic based laser Doppler flowmeter (Perimed P...

In a recent article in this journal, Grunwald et al. 1 quantified foveolar choroidal blood flow using a Laser Doppler flowmeter in patients with nonexudative age-related macular degeneration (AMD). They found that choroidal blood volume and choroidal blood flow in patients with AMD were significantly reduced. However, they found no statistically significant difference for the choroidal blood ve...