Laser-Doppler flowmetry

FIGURE 1.10 Laser-doppler flowmetry (a) and NO measurement (b) from one subject. Upon heating the subject to 39°C, at 10 min, NO production and skin blood flow increased, which instantly returned to normal upon cooling the subject at 45 min. After heat stress and cooling, ACh was administered by intra-dermal microdialysis to confirm the ability of the microelectrode to measure NO concentrations. (Reprinted with permission from the American Physiological Society [125].)... 

Wahlberg JE. 1984. Erythema-inducing effects of solvents following epicutaneous administration to man-studied by laser doppler flowmetry. Scand J Work Environ Health 10 159-162. 

Didier A, Droy-Lefaix MT, Aurousseau C, Cazals Y. (1996). Effects of Ginkgo biloba extract (EGb 761) on cochlear vasculature in the guinea pig morphometric measurements and laser Doppler flowmetry. Eur Arch Otorhinolaryngol. 253(1-2) 25-30. 

Canady, J.W., et al. 1993. Measurement of blood flow in the skin and oral mucosa of the rhesus monkey (Macaca mulatto) using laser Doppler flowmetry. Comp Biochem Physiol Comp Physiol 106 61. 

Cerebral blood flow (CBF) was monitored in the cerebral cortex of the ischemic hemisphere corresponding to the supply territory of the middle cerebral artery by laser-doppler flowmetry (DRT4, Moor Instruments, Devon, UK). To this aim, a rectangular bent laser-doppler probe was glued onto the parietal bone (2 mm posterior and 5 mm lateral from bregma) and local CBF was continuously measured from 20 min before the onset of ischemia until 10 min after reperfusion, keeping the animal under isoflurane anaesthesia. Flow values were collected every 5 min before MCAo and after reperfusion whereas data were collected at 10 min intervals during occlusion. 

Fluorescein angiography, ocular blood flow analysis via laser Doppler flowmetry, color vision measurements, contrast sensitivity testing, and electrophysiological tests (e.g., pattern electroretinograms) are used as research tools in the evaluation of POAG patients. Routine clinical use is not advocated at this time. 

The vascular theory (Hayreh et al., 1970) proposes that cell death is triggered by ischemia, whether induced by elevated lOP or as a primary insult. Studies done to evaluate the circulation of the optic nerve using the laser Doppler flowmetry have shown diminished blood flow in the optic nerves of eyes with POAG (Grunwald et al., 1998). 

Heier MS, Nilsen T, Graver V, Aass N, Fossa SD. Raynaud s phenomenon after combination chemotherapy of testicular cancer, measured by laser Doppler flowmetry. A pilot study. Br J Cancer 1991 63(4) 550-2. 

Many industries regularly conduct repeat insult patch tests on human volunteers to evaluate topical irritancy. Groups of human volunteers are patched with test substance. One to five concentrations can be tested simultaneously, a wide enough range to yield results relevant to the usage. Cumulative skin irritancy is measured by applying patch applications each day for 3 weeks. Skin irritation is usually assessed visually, but blood flow and skin temperature can be measured objectively by laser Doppler flowmetry, ultrasound Doppler, heat flow disk measurement, sensitive thermocouple devices, or noncontact infrared radiative techniques. In these tests, dose-response curves can be obtained. Skin thickness can be measured with calipers as a measure of edema formation. 

Another interesting paper was published by Wolf et al. in 1996 [39] where they used NIR and laser Doppler flowmetry (LDF) to study the effect of systemic nitric oxide synthase (NOS) inhibition on brain oxygenation. The study, performed on rats, demonstrated no effects on brain oxygenation during cortical spreading depression (CSD). 

Butoxyethanol acetate was used to evaluate a noninvasive human method and an in vitro cytotoxicity method as alternatives to the rabbit skin test for primary irritant effects (Jacobs et al. 1989). The human method included measurements of cutaneous blood flow values (CBFV) by laser Doppler flowmetry before and after patch application on the forearm some experiments used 100% test substances (75 mg/cm ) applied for 48 hours and measured 12 hours later, and other experiments used 10% solutions of test substances (7.5 mg/m ) applied for 3 hours and measured 1, 24, 48, and 72 hours later. Cutaneous blood flow values (CBFV) obtained in the two series of experiments (10% for 3 hours and 100% for 48 hours) resulted in a ranking of 2, which is the minimal mean erythema needed to classify substances as skin irritants. The CBFV in humans correlated very well (r=0.99) with erythema scores obtained on rabbits. 

Pigott, K. H., Hill, S. A., Chaplin, D. J., and Saunders, M. I. (1996) Microregional fluctuations in perfusion within human tumours detected using laser Doppler flowmetry. Radiother. Oncol. 40,45-50. 

Emtestam, L., Kuzmina, N., Talme, T., 2007. Evaluation of the effects of topical clobetasol propionate by visual score, electrical impedance and laser Doppler flowmetry. Skin Res. Technol. 13, 73—78. 

Engelhart, M., and Kristensen, J. K., 1986, Raynaud s Hienomenon Blood Supply to Fingers During Indirect Cooling, Evaluated by Laser Doppler Flowmetry, Clin. Physiol., 6 481-488. 

Schabauer, A. M. A., and Rooke, T. W., 1994, Cutaneous Laser Doppler Flowmetry Applications and Findings, Mayo. Clin. Proc., 69 564-574. 

Smits, G. J., Roman, R. J., and Lombard, J. H., 1986, Evaluation of Laser-doppler Flowmetry as a Measure of Tissue Blood Flow, J. Appl. Physiol., 61(2) 666-672. 

Evaluation of the irritant potential of collected materials on the skin of workers or volunteers by means of noninvasive techniques (such as transepi-dermal water loss, erythrometry, laser-Doppler flowmetry and others). 

Lachapelle JM, Mahmoud G, Vanherle R (1984) Anhydrite dermatitis in coal mines an airborne irritant reaction assessed by laser Doppler flowmetry. Contact Dermatitis 11 188-189... 

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