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.

Optimized mouse model of embolic MCAO: From cerebral blood flow to neurological outcomes

2020 ◽  
pp. 0271678X2091762 ◽  
Author(s):  
Rongrong Wang ◽  
Hailian Wang ◽  
Yaan Liu ◽  
Di Chen ◽  
Yangfan Wang ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Mouse Model ◽  
Infarct Volume ◽  
Laser Speckle ◽  
Core Area ◽  
Contrast Imaging ◽  
Vessel Occlusion ◽  
Doppler Flowmetry

The embolic middle cerebral artery occlusion (eMCAO) model mimics ischemic stroke due to large vessel occlusion in humans and is amenable to thrombolytic therapy with rtPA. However, two major obstacles, the difficulty of the eMCAO surgery and unpredictable occurrence of clot autolysis, had impeded its application in mice. In this study, we modified catheters to produce suitable fibrin-rich embolus and optimized the eMCAO model using cerebral blood flow (CBF) monitored by both laser Doppler flowmetry (LDF) and 2D laser speckle contrast imaging (LSCI) to confirm occlusion of MCA. The results showed that longer embolus resulted in higher mortality. There was a compensatory increase in MCA territory perfusion after eMCAO associated with decreased infarct volume; however, this was only partly dependent on recanalization as clot autolysis was only observed in ∼30% of mice. Cortical CBF monitoring with LSCI showed that the size of peri-core area at 3 h displayed the best correlation with infarct volume that is attributed to compensatory collateral blood flow. The peri-core area best predicted functional outcome after eMCAO. In summary, we developed a reliable eMCAO mouse model that better mimics embolic ischemic stroke in humans, which will increase the potential for successful translation of stroke neuroprotective therapies.

Posterior ocular blood flow in preeclamptic patients evaluated with optical coherence tomography angiography

2019 ◽  
Vol 17 ◽  
pp. 203-208
Author(s):  
Selma Urfalıoglu ◽  
Murat Bakacak ◽  
Gökhan Özdemir ◽  
Mete Güler ◽  
Abdullah Beyoglu ◽  
...  
Keyword(s):  
Blood Flow ◽  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Ocular Blood Flow ◽  
Optical Coherence

scholarly journals Ocular blood flow assessment in vascular pathology of the eye

2015 ◽  
Vol 14 (4) ◽  
pp. 4-10 ◽  
Author(s):  
T. N. Kiseleva ◽  
N. A. Adzhemian
Keyword(s):  
Blood Flow ◽  
Power Doppler ◽  
Ocular Blood Flow ◽  
Doppler Imaging ◽  
Vascular Pathology ◽  
Vascular Lesions ◽  
Doppler Flowmetry ◽  
Eye Color ◽  
Retinal Vascular Caliber ◽  
Retinal Photographs

The review discusses some of the most common methods of ocular microcirculation assessment in vascular lesions of the eye: color and power Doppler imaging, laser Doppler flowmetry, fluorescent and indocyanine green angiography, digital retinal photographs and measurement of retinal vascular caliber, pulsative ocular blood flow analyzer, OCT-angiography. These methods are used in diagnostic of impairment of blood flow in vessels of optic nerve and retina, which also are full informative in early diagnostic of vascular pathology of eye.

Evidence Based Burn Depth Assessment Using Laser-Based Technologies: Where Do We Stand?

2020 ◽  
Author(s):  
Karel E Y Claes ◽  
Henk Hoeksema ◽  
Tom Vyncke ◽  
Jozef Verbelen ◽  
Petra De Coninck ◽  
...  
Keyword(s):  
Laser Speckle ◽  
Laser Doppler ◽  
Doppler Imaging ◽  
Measurement Tool ◽  
Evidence Based ◽  
Aesthetic Outcome ◽  
Contrast Imaging ◽  
Doppler Flowmetry ◽  
Burn Depth ◽  
Burn Depth Assessment

Abstract Early clinical assessment of burn depth and associated healing potential (HP) remains extremely challenging, even for experienced surgeons. Inaccurate diagnosis often leads to prolonged healing times and unnecessary surgical procedures, resulting in incremental costs, and unfavorable outcomes. Laser Doppler imaging (LDI) is currently the most objective and accurate diagnostic tool to measure blood flow and its associated HP, the main predictor for a patient’s long-term functional and aesthetic outcome. A systematic review was performed on non-invasive, laser-based methods for burn depth assessment using skin microcirculation measurements to determine time to healing: Laser Doppler flowmetry (LDF), LDI and laser speckle contrast imaging (LSCI). Important drawbacks of single point LDF measurements are direct contact with numerous small points on the wound bed and the need to carry out serial measurements over several days. LDI is a fast, “non-contact,” single measurement tool allowing to scan large burned areas with a 96% accuracy. LDI reduces the number of surgeries, improves the functional and aesthetic outcome and is cost-effective. There is only limited evidence for the use of LSCI in burn depth assessment. LSCI still needs technical improvements and scientific validation, before it can be approved for reliable burn assessment. LDI has proven to be invaluable in determining the optimal treatment of a burn patient. For unclear reasons, LDI is still not routinely used in burn centers worldwide. Additional research is required to identify potential “barriers” for universal implementation of this evidence-based burn depth assessment tool.

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