The influence of hemorrhagic shock on ocular microcirculation by obtained by laser speckle flowgraphy in a white rabbit model

2021 ◽  
Author(s):  
Kento Watanabe ◽  
Tomoaki Shiba ◽  
Tetsuya Komatsu ◽  
Kiyoshi Sakuma ◽  
Megumi Aimoto ◽  
...  
Keyword(s):  
Hemorrhagic Shock ◽  
Rabbit Model ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy

scholarly journals Longitudinal effects of common carotid artery stenosis on ocular hemodynamics assessed using laser speckle flowgraphy in a rabbit model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Aishah Ismail ◽  
Hui Cheng Chen ◽  
Ibrahima Faye ◽  
Tong Boon Tang
Keyword(s):  
Carotid Artery ◽  
Common Carotid Artery ◽  
Carotid Artery Stenosis ◽  
Rabbit Model ◽  
Laser Speckle ◽  
Artery Stenosis ◽  
Laser Speckle Flowgraphy ◽  
Stroke Severity ◽  
Post Surgery ◽  
The Impact

Abstract Real-time impairment of ocular blood flow (OBF) under common carotid artery stenosis (CCAS) has not been ascertained. We aimed to longitudinally assess the impact of CCAS on OBF using a rabbit model. About 75% stenosis was created by tying the common carotid artery with a plastic mandrel using a nylon suture. The plastic mandrel was gently removed, leaving a ligature. Neurological and behavioral assessments were recorded as the clinical indicator of stroke severity. With laser speckle flowgraphy, the pulse waveform parameters namely mean blur rate (MBR), blowout score (BOS), blowout time (BOT), rising rate, S1-area, falling rate (FR), S2-area, flow acceleration index (FAI), acceleration time index, resistive index (RI) and the difference between the maximum and minimum values of MBR (AC) were assessed in overall, vessel, and tissue regions of the optic nerve head (ONH). Longitudinally, BOS significantly increased until day 19 post-surgery, whereas FAI, RI, and AC significantly decreased. Beyond day 19, BOS, BOT, FR, FAI, RI, and AC significantly decreased. We defined two stages representing impaired vessel conditions, namely the vessel resistance phase, where BOS increases and FAI, RI, and AC decrease, and the vessel elasticity phase where BOS, BOT, FR, FAI, RI and AC decrease. These stages provide information about atherosclerosis, assessable non-invasively through the eye.

scholarly journals Hallucal thenar index: A new index to detect peripheral arterial disease using laser speckle flowgraphy

Vascular ◽  
2020 ◽  
pp. 170853812093893
Author(s):  
Kazuhiro Tsunekawa ◽  
Fumio Nagai ◽  
Tamon Kato ◽  
Ikkei Takashimizu ◽  
Daisuke Yanagisawa ◽  
...  
Keyword(s):  
Blood Flow ◽  
Peripheral Arterial Disease ◽  
Operating Characteristic ◽  
Ankle Brachial Index ◽  
Arterial Disease ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Skin Perfusion ◽  
Peripheral Arterial ◽  
Cutaneous Blood

Objectives Laser speckle flowgraphy is a technology using reflected scattered light for visualization of blood distribution, which can be used to measure relative velocity of blood flow easily without contact with the skin within a short time. It was hypothesized that laser speckle flowgraphy may be able to identify foot ischemia. This study was performed to determine whether laser speckle flowgraphy could distinguish between subjects with and without peripheral arterial disease. Materials and methods All subjects were classified based on clinical observations using the Rutherford classification: non-peripheral arterial disease, class 0; peripheral arterial disease group, class 2–5. Rutherford class 6 was one of the exclusion criteria. Laser speckle flowgraphy measured the beat strength of skin perfusion as an indicator of average dynamic cutaneous blood flow change synchronized with the heartbeat. The beat strength of skin perfusion indicates the strength of the heartbeat on the skin, and the heartbeat strength calculator in laser speckle flowgraphy uses the blood flow data to perform a Fourier transform to convert the temporal changes in blood flow to a power spectrum. A total of 33 subjects with peripheral arterial disease and 40 subjects without peripheral arterial disease at a single center were prospectively examined. Laser speckle flowgraphy was used to measure hallucal and thenar cutaneous blood flow, and the measurements were repeated three times. The hallucal and thenar index was defined as the ratio of beat strength of skin perfusion value on hallux/beat strength of skin perfusion value on ipsilateral thenar eminence. The Mann–Whitney U-test was used to compare the median values of hallucal and thenar index and ankle brachial index between the two groups. A receiver operating characteristic curve for hallucal and thenar index of beat strength of skin perfusion was plotted, and a cutoff point was set. The correlation between hallucal and thenar index of beat strength of skin perfusion and ankle brachial index was explored in all subjects, the hemodialysis group, and the non-hemodialysis (non-hemodialysis) group. Results The median value of the hallucal and thenar index of beat strength of skin perfusion was significantly different between subjects with and without peripheral arterial disease (0.27 vs. 0.87, respectively; P <  0.001). The median value of ankle brachial index was significantly different between subjects with and without peripheral arterial disease (0.8 vs. 1.1, respectively; P <  0.001). Based on the receiver operating characteristic of hallucal and thenar index, the cutoff was 0.4416 and the sensitivity, specificity, positive predictive value, and negative predictive value were 68.7%, 95%, 91.7%, and 77.6%, respectively. The correlation coefficients of all subjects, the hemodialysis group, and the non-hemodialysis group were 0.486, 0.102, and 0.743, respectively. Conclusions Laser speckle flowgraphy is a noninvasive, rapid, and widely applicable method. Laser speckle flowgraphy using hallucal and thenar index would be helpful to determine the differences between subjects with and without peripheral arterial disease. The correlation between hallucal and thenar index of beat strength of skin perfusion and ankle brachial index indicated that this index was especially useful in the non-hemodialysis group.

scholarly journals Detection of significantly high vitreous concentrations of fatty acid-binding protein 4 in patients with proliferative diabetic retinopathy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kaku Itoh ◽  
Masato Furuhashi ◽  
Yosuke Ida ◽  
Hiroshi Ohguro ◽  
Megumi Watanabe ◽  
...  
Keyword(s):  
Blood Flow ◽  
Diabetic Retinopathy ◽  
Fatty Acid ◽  
Proliferative Diabetic Retinopathy ◽  
Ocular Blood Flow ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Fatty Acid Binding ◽  
High Positive Correlation ◽  
Blood Biochemical

AbstractThe fatty acid-binding protein4 (FABP4) and vascular endothelial growth factor A (VEGFA) play key roles in the metabolic and cardiovascular diseases, and proliferative diabetic retinopathy (PDR), respectively. To identify FABP4 in vitreous fluid in PDR, vitreous concentrations of FABP4 (V-FABP4) and VEGFA (V-VEGFA) from PDR (n = 20) and non-PDR (n = 20) patients were determined by Enzyme-Linked ImmunoSorbent Assays. The data, which included height and weight, systemic blood pressures, several blood biochemical parameters and blood flow at the optic nerve head (ONH) by laser speckle flowgraphy (LSFG) were collected. The levels of V-FABP4 and V-VEGFA were significantly higher in PDR patients than in non-PDR patients (P < 0.001) with a high positive correlation (r = 0.72, P < 0.001) between them. The findings were not affected by body mass index values and the presence of vitreous hemorrhaging. Among the clinical parameters, V-FABP4 correlated positively with creatinine and negatively with age and aspartate transaminase (AST) levels, while V-VEGFA correlated positively with fasting plasma glucose and hemoglobin A1c (HbA1c) levels but negatively with AST. Multiple regression analyses indicated that V-VEGFA, or V-FABP4, AST and HbA1c were independent predictors of V-FABP4 or V-VEGFA, respectively. Both were negatively correlated, but more evident in V-FABP4, with the ONH ocular blood flow.

scholarly journals Association of changes of retinal vessels diameter with ocular blood flow in eyes with diabetic retinopathy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yoshitaka Ueno ◽  
Takeshi Iwase ◽  
Kensuke Goto ◽  
Ryo Tomita ◽  
Eimei Ra ◽  
...  
Keyword(s):  
Blood Flow ◽  
Diabetic Retinopathy ◽  
Adaptive Optics ◽  
Laser Speckle ◽  
The Other ◽  
Systemic Hypertension ◽  
Laser Speckle Flowgraphy ◽  
Retinal Vessels ◽  
External Diameter ◽  
The Mean

AbstractWe investigated morphological changes of retinal arteries to determine their association with the blood flow and systemic variables in type 2 diabetes patients. The patients included 47 non-diabetic retinopathy eyes, 36 mild or moderate nonproliferative diabetic retinopathy (M-NPDR) eyes, 22 severe NPDR (S-NPDR) eyes, 32 PDR eyes, and 24 normal eyes as controls. The mean wall to lumen ratio (WLR) measured by adaptive optics camera was significantly higher in the PDR groups than in all of the other groups (all P < 0.001). However, the external diameter of the retinal vessels was not significantly different among the groups. The mean blur rate (MBR)-vessel determined by laser speckle flowgraphy was significantly lower in the PDR group than in the other groups (P < 0.001). The WLR was correlated with MBR-vessel (r = − 0.337, P < 0.001), duration of disease (r = 0.191, P = 0.042), stage of DM (r = 0.643, P < 0.001), systolic blood pressure (r = 0.166, P < 0.037), and presence of systemic hypertension (r = 0.443, P < 0.001). Multiple regression analysis demonstrated that MBR-vessel (β = − 0.389, P < 0.001), presence of systemic hypertension (β = 0.334, P = 0.001), and LDL (β = 0.199, P = 0.045) were independent factors significantly associated with the WLR. The increased retinal vessel wall thickness led to a narrowing of lumen diameter and a decrease in the blood flow in the PDR group.

scholarly journals Effects of water drinking test on ocular blood flow waveform parameters: A laser speckle flowgraphy study

PLoS ONE ◽  
2017 ◽  
Vol 12 (7) ◽  
pp. e0181512 ◽  
Author(s):  
Mehwish Saba Bhatti ◽  
Tong Boon Tang ◽  
Augustinus Laude
Keyword(s):  
Blood Flow ◽  
Ocular Blood Flow ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Flow Waveform ◽  
Water Drinking ◽  
Drinking Test ◽  
Water Drinking Test

scholarly journals Structural evaluation in inherited retinal diseases

2021 ◽  
pp. bjophthalmol-2021-319228
Author(s):  
Malena Daich Varela ◽  
Burak Esener ◽  
Shaima A Hashem ◽  
Thales Antonio Cabral de Guimaraes ◽  
Michalis Georgiou ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Fundus Autofluorescence ◽  
Standard Of Care ◽  
Laser Speckle ◽  
Fundus Photography ◽  
Laser Speckle Flowgraphy ◽  
Retinal Diseases ◽  
Autofluorescence Imaging ◽  
Structural Evaluation ◽  
Fundus Imaging

Ophthalmic genetics is a field that has been rapidly evolving over the last decade, mainly due to the flourishing of translational medicine for inherited retinal diseases (IRD). In this review, we will address the different methods by which retinal structure can be objectively and accurately assessed in IRD. We review standard-of-care imaging for these patients: colour fundus photography, fundus autofluorescence imaging and optical coherence tomography (OCT), as well as higher-resolution and/or newer technologies including OCT angiography, adaptive optics imaging, fundus imaging using a range of wavelengths, magnetic resonance imaging, laser speckle flowgraphy and retinal oximetry, illustrating their utility using paradigm genotypes with on-going therapeutic efforts/trials.

scholarly journals Reproducibility of retinal circulation measurements obtained using laser speckle flowgraphy-NAVI in patients with glaucoma

2011 ◽  
pp. 1171 ◽  
Author(s):  
Toru Nakazawa ◽  
Naoko Aizawa ◽  
Yu Yokoyama ◽  
Naoki Chiba ◽  
Kazuko Omodaka ◽  
...  
Keyword(s):  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Retinal Circulation

scholarly journals Ocular blood flow values measured by laser speckle flowgraphy correlate with the postmenstrual age of normal neonates

2016 ◽  
Vol 254 (8) ◽  
pp. 1631-1636 ◽  
Author(s):  
Tadashi Matsumoto ◽  
Takashi Itokawa ◽  
Tomoaki Shiba ◽  
Yuuji Katayama ◽  
Tetsushi Arimura ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ocular Blood Flow ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Postmenstrual Age ◽  
Normal Neonates
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