A study on blood flow effects with Polarization Sensitive Optical Coherence Tomography

2004 ◽  
Author(s):  
H. N. Zaatari ◽  
N. J. Kemp ◽  
J. Park ◽  
H. G. Rylander ◽  
T. E. Milner
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Optical Coherence ◽  
Flow Effects

Blood Vessel Density Measured Using Dynamic Optical Coherence Tomography is a Tool for Wound Healers

2021 ◽  
pp. 153473462110173
Author(s):  
Rajgopal Mani ◽  
Jon Holmes ◽  
Kittipan Rerkasem ◽  
Nikolaos Papanas
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Blood Vessel ◽  
Chronic Wounds ◽  
Vessel Density ◽  
Optical Coherence ◽  
Skin Microcirculation ◽  
Wound Edge ◽  
Venous Ulcers ◽  
Oct Imaging

Dynamic optical coherence tomography (D-OCT) is a relatively new technique that may be used to study the substructures in the retina, in the skin and its microcirculation. Furthermore, D-OCT is a validated method of imaging blood flow in skin microcirculation. The skin around venous and mixed arterio-venous ulcers was imaged and found to have tortuous vessels assumed to be angiogenic sprouts, and classified as dots, blobs, coils, clumps, lines, and curves. When these images were analyzed and measurements of vessel density were made, it was observed that the prevalence of coils and clumps in wound borders was significantly greater compared with those at wound centers. This reinforced the belief of inward growth of vessels from wound edge toward wound center which, in turn, reposed confidence in following the wound edge to study healing. D-OCT imaging permits the structure and the function of the microcirculation to be imaged, and vessel density measured. This offers a new vista of skin microcirculation and using it, to better understand angiogenesis in chronic wounds.

scholarly journals Visualization of three-dimensional microcirculation of rodents’ retina and choroid for studies of critical illness using optical coherence tomography angiography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jang Ryul Park ◽  
ByungKun Lee ◽  
Min Ji Lee ◽  
Kyuseok Kim ◽  
Wang-Yuhl Oh
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Severe Sepsis ◽  
Critical Illness ◽  
Hemorrhagic Shock ◽  
Optical Coherence Tomography Angiography ◽  
Flow Index ◽  
Optical Coherence ◽  
Sepsis Model ◽  
Lactate Levels

AbstractWe developed a method to measure the relative blood flow speed using optical coherence tomography angiography (OCTA) in retina and choroid, and investigated the feasibility of this method for assessing microcirculatory function in rat models of sepsis and hemorrhagic shock. Two sepsis models, 6-h severe sepsis without treatment and 30-h moderate sepsis maintaining mean arterial pressure, and volume controlled hemorrhagic shock and fluid resuscitation model were used to see the change of microcirculation. The blood flow index (BFI), which was calculated from the OCTA images to represent the average relative blood flow, was decreasing during the 6-h severe sepsis model. Its change is in parallel with the mean arterial blood pressure (MAP) and blood lactate levels. In the 30-h moderate sepsis model, the BFI was decreased while maintaining MAP, and lactate was increased. In the hemorrhagic shock model, the change of BFI is in line with MAP and lactate levels. In all models, BFI change is more sensitive in choroid than in retina. This study presents the OCTA-based retinal and choroidal microcirculatory blood flow monitoring method and shows its utility for assessment of critical illness.

scholarly journals Modern Diagnostic Techniques for the Assessment of Ocular Blood Flow in Myopia: Current State of Knowledge

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ewa Grudzińska ◽  
Monika Modrzejewska
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Refractive Error ◽  
Retinal Vessel ◽  
Ocular Blood Flow ◽  
Laser Speckle ◽  
Doppler Imaging ◽  
Optical Coherence ◽  
Contrast Imaging ◽  
Doppler Flowmetry

Myopia is the most common refractive error and the subject of interest of various studies assessing ocular blood flow. Increasing refractive error and axial elongation of the eye result in the stretching and thinning of the scleral, choroid, and retinal tissues and the decrease in retinal vessel diameter, disturbing ocular blood flow. Local and systemic factors known to change ocular blood flow include glaucoma, medications and fluctuations in intraocular pressure, and metabolic parameters. Techniques and tools assessing ocular blood flow include, among others, laser Doppler flowmetry (LDF), retinal function imager (RFI), laser speckle contrast imaging (LSCI), magnetic resonance imaging (MRI), optical coherence tomography angiography (OCTA), pulsatile ocular blood flowmeter (POBF), fundus pulsation amplitude (FPA), colour Doppler imaging (CDI), and Doppler optical coherence tomography (DOCT). Many researchers consistently reported lower blood flow parameters in myopic eyes regardless of the used diagnostic method. It is unclear whether this is a primary change that causes secondary thinning of ocular tissues or quite the opposite; that is, the mechanical stretching of the eye wall reduces its thickness and causes a secondary lower demand of tissues for oxygen. This paper presents a review of studies assessing ocular blood flow in myopes.

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