Impact of acute dynamic exercise on vascular stiffness in the retinal arteriole in healthy subjects

2021 ◽  
Author(s):  
Tsukasa Ikemura ◽  
Nobuhiro Nakamura ◽  
Naoyuki Hayashi
Keyword(s):  
Acute Exercise ◽  
Young Men ◽  
Dynamic Exercise ◽  
Laser Speckle ◽  
Vascular Stiffness ◽  
Laser Speckle Flowgraphy ◽  
Pulse Waveform ◽  
Retinal Arteriole ◽  
Conduit Artery ◽  
Retinal Arterioles

Acute exercise can improve vascular stiffness in the conduit artery, but its effect on the retinal arterioles is unknown. The present study investigated the effects of acute dynamic exercise on retinal vascular stiffness. In experiment 1, we measured the cardio-ankle vascular index (CAVI), carotid artery intima-media thickness (carotid IMT), and retinal blood velocity by laser speckle flowgraphy in 28 healthy old and 28 young men (69 ± 3 and 23 ± 3 years, respectively). Pulse waveform variables, which were used as an index of retinal vascular stiffness, were assessed by retinal blood flow velocity profile analysis. In experiment 2, 18 healthy old and 18 young men (69 ± 3 and 23 ± 3 years, respectively) underwent assessment of pulse waveform variables after a 30-min bout of moderate cycling exercise at an intensity of 60% heart rate reserve. There was a significant difference in the baseline pulse waveform variables between the old and young groups. Pulse waveform variables in the retinal arteriole did not significantly change after acute dynamic exercise, whereas CAVI significantly decreased. These findings suggest that retinal vascular stiffness does not change by acute exercise. The effect of exercise on vascular stiffness in the retinal arterioles might be different from that in the conduit artery.

Facial Blood Flow Responses to Dynamic Exercise

2020 ◽  
Author(s):  
Naoyuki Hayashi ◽  
Hideaki Kashima ◽  
Tsukasa Ikemura
Keyword(s):  
Blood Flow ◽  
Exercise Intensity ◽  
Regional Differences ◽  
Regional Blood Flow ◽  
Dynamic Exercise ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Handgrip Exercise ◽  
Post Hoc ◽  
One Way Anova

AbstractWe reported previously that a static handgrip exercise evoked regional differences in the facial blood flow. The present study examined whether regional differences in facial blood flow are also evoked during dynamic exercise. Facial blood flow was measured by laser speckle flowgraphy during 15 min of cycling exercise at heart rates of 120 bpm, 140 bpm and 160 bpm in 12 subjects. The facial vascular conductance index was calculated from the blood flow and mean arterial pressure. The regional blood flow and conductance index values were determined in the forehead, eyelid, nose, cheek, ear and lip. One-way ANOVA and Tukey’s post-hoc test were used to examine effects of exercise intensity and target regions. The blood flow and conductance index in skin areas increased significantly with the exercise intensity. The blood flow and conductance index in the lip increased significantly at 120 bpm and 140 bpm compared to the control, while the values in the lip at 160 bpm did not change from the control values. These results suggest that the blood flow in facial skin areas, not in the lip, responds similarly to dynamic exercise, in contrast to the responses to static exercise.

scholarly journals Changes in Pulse Waveforms in Response to Intraocular Pressure Elevation Determined by Laser Speckle Flowgraphy in Healthy Subjects

2021 ◽  
Author(s):  
Chie Iwase ◽  
Takeshi Iwase ◽  
Ryo Tomita ◽  
Tomohiko Akahori ◽  
Eimei Ra ◽  
...  
Keyword(s):  
Blood Flow ◽  
Intraocular Pressure ◽  
Normal Subjects ◽  
Laser Speckle ◽  
University Hospital ◽  
Laser Speckle Flowgraphy ◽  
Pulse Waveform ◽  
Cross Sectional ◽  
Flow Acceleration ◽  
Iop Elevation

Abstract Background: To determine whether autoregulation of the blood flow is present in the blood flow on the optic nerve head (ONH) by intraocular pressure (IOP) elevations using pulse waveform parameters determined by laser speckle flowgraphy (LSFG) in normal subjects.Methods: We conducted this prospective cross sectional study at the Nagoya University Hospital. An ophthalmodynamometer was pressed on the sclera to increase the IOP by 20 mmHg or 30 mmHg for 1 min (Experiment 1, 16 subjects) and by 30 mmHg for 10 min (Experiment 2, 10 subjects). The mean blur rate (MBR) and the eight pulse waveform parameters determined by LSFG were measured before, immediately after and during an IOP elevation, and after the IOP returned to the baseline pressure.Results: A significant elevation of the IOP and a significant reduction in the ocular perfusion pressure (OPP) were found after applying the ophthalmodynamometer (both, P<0.001). The blowout score (BOS) (P<0.001) was significantly reduced, and the flow acceleration index (FAI; P<0.01) and resistivity index (RI; P<0.001) was significantly increased immediately after increasing the IOP by 20 or 30 mmHg (Experiment 1). During the IOP elevation throughout the 10 min, the BOS and the RI significantly recovered to the baseline at time 10 compared to time 0, (P <0.001 and P = 0.008, respectively) (Experiment 2).Conclusions: Our results indicate that the blood flow on the ONH is autoregulated by several mechanisms for changes in the OPP induced by an elevation of the IOP in normal subjects.

scholarly journals Changes in pulse waveforms in response to intraocular pressure elevation determined by laser speckle flowgraphy in healthy subjects

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chie Iwase ◽  
Takeshi Iwase ◽  
Ryo Tomita ◽  
Tomohiko Akahori ◽  
Kentaro Yamamoto ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Normal Subjects ◽  
Cross Sectional Study ◽  
Laser Speckle ◽  
University Hospital ◽  
Laser Speckle Flowgraphy ◽  
Pulse Waveform ◽  
Cross Sectional ◽  
Flow Acceleration ◽  
Iop Elevation

Abstract Background The influences of intraocular pressure (IOP) elevations on the pulse waveform in the optic nerve head (ONH) were evaluated using laser speckle flowgraphy (LSFG) in normal subjects. Methods This prospective cross-sectional study was conducted at the Nagoya University Hospital. An ophthalmodynamometer was pressed on the sclera to increase the IOP by 20 mmHg or 30 mmHg for 1 min (experiment 1, 16 subjects) and by 30 mmHg for 10 min (experiment 2, 10 subjects). The mean blur rate (MBR) and the eight pulse waveform parameters determined using LSFG were measured before, immediately after and during an IOP elevation, and after the IOP returned to the baseline pressure. Results A significant elevation in the IOP and a significant reduction in the ocular perfusion pressure (OPP) were found after applying the ophthalmodynamometer (both, P < 0.001). The blowout score (BOS) reduced significantly (P < 0.001), and the flow acceleration index (FAI; P < 0.01) and resistivity index (RI; P < 0.001) increased significantly immediately after increasing the IOP by 20 or 30 mmHg (experiment 1). The BOS reduced significantly (P < 0.001), and the FAI (P < 0.01) and RI (P < 0.001) increased significantly after the IOP elevation by 30 mmHg in both experiment 2 and 1. However, the BOS and RI recovered significantly at time 10 compared to that in time 0 (immediately after IOP elevation) during the 10-min IOP elevation (P < 0.001 and P = 0.008, respectively). Conclusions In conclusion, the BOS, FAI, and RI of the pulse waveforms changed significantly with an acute elevation in the IOP. The change should be related to the larger difference between the maximum and minimum MBRs during the IOP elevation.

scholarly journals Influence of age and gender on the pulse waveform in optic nerve head circulation in healthy men and women

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tatsuhiko Kobayashi ◽  
Tomoaki Shiba ◽  
Yuji Nishiwaki ◽  
Ayako Kinoshita ◽  
Tadashi Matsumoto ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Pulse Waveform ◽  
Strongly Correlated ◽  
Age And Gender ◽  
Arterial Blood ◽  
Optic Nerve Head Circulation ◽  
And Gender

AbstractThe influences of age and gender differences on the pulse waveform in the optic nerve head (ONH) in healthy adults, using laser speckle flowgraphy (LSFG) were evaluated. We studied 908 healthy subjects (men = 701, age: 50.0 ± 9.1, women = 208, age: 49.8 ± 9.5, p = 0.76), evaluating these pulse waveform parameters: the blowout score (BOS), blowout time (BOT), acceleration time index (ATI), and the rising and falling rates. The parameters were analyzed separately for the tissue, vessels, and throughout the optic nerve head (All). All parameters were compared between genders. We investigated which independent factors for the pulse waveform in the ONH is most strongly correlated with age. All sections of the BOS, BOT, ATI, and falling rate showed a significant gender difference. A univariate regression analysis revealed that BOT-Tissue showed the strongest correlation with age (r = −0.51). The factors contributing independently to the BOT-Tissue were gender, age, heart rate, mean arterial blood pressure, pulse pressure, spherical refraction, and estimated glomerular filtration rate. Among the subjects aged >41 years, the chronological changes of BOT-Tissue in the women were significantly lower than those in the men. We concluded that the pulse waveform in the ONH has clear differences between the genders and shows chronological changes.

Pulse-Waveform Analysis of Normal Population using Laser Speckle Flowgraphy

2014 ◽  
Vol 39 (12) ◽  
pp. 1207-1215 ◽  
Author(s):  
Satoru Tsuda ◽  
Hiroshi Kunikata ◽  
Masahiko Shimura ◽  
Naoko Aizawa ◽  
Kazuko Omodaka ◽  
...  
Keyword(s):  
Normal Population ◽  
Laser Speckle ◽  
Waveform Analysis ◽  
Laser Speckle Flowgraphy ◽  
Pulse Waveform ◽  
Pulse Waveform Analysis

scholarly journals Time Course in Ocular Blood Flow and Pulse Waveform in a Case of Ocular Ischemic Syndrome with Intraocular Pressure Fluctuation

Vision ◽  
2020 ◽  
Vol 4 (2) ◽  
pp. 31
Author(s):  
Ryo Yamazaki ◽  
Ryuya Hashimoto ◽  
Hidetaka Masahara ◽  
Masashi Sakamoto ◽  
Takatoshi Maeno
Keyword(s):  
Blood Flow ◽  
Visual Acuity ◽  
Intraocular Pressure ◽  
Ocular Blood Flow ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Pulse Waveform ◽  
Rubeosis Iridis ◽  
Ocular Ischemic Syndrome ◽  
Ischemic Syndrome

We report on a 70-year-old Japanese man with complaints of worsening left visual acuity who was diagnosed with ocular ischemic syndrome (OIS) associated with internal carotid artery (ICA) stenosis. A gonioscopy examination showed rubeosis iridis and elevated intraocular pressure (IOP) in the left eye (50 mmHg) at the baseline visit. The optic nerve head (ONH) and choroidal blood flow measured by laser speckle flowgraphy (LSFG) was impaired in the left eye compared with that in the right eye. Additionally, the blowout score (BOS), which indicates the variation of the mean blur rate (MBR) during systolic and diastolic periods, was decreased in the left eye. After treatment with an injection of bevacizumab and administration of Rho-associated kinase-inhibitor ripasudil eye drops, both ocular blood flow and BOS in each vascular bed gradually increased along with IOP reduction. The visual acuity also improved. The current case demonstrated increased blood flow and decreased fluctuation of blood flow in the ONH and choroid before and after the treatment in OIS with rubeosis iridis. The LSFG technique is useful to non-invasively assess the ocular circulation and pulse waveform in OIS.

scholarly journals Diurnal variation of pulse waveform parameters determined by laser speckle flowgraphy on the optic nerve head in healthy subjects

Medicine ◽  
2017 ◽  
Vol 96 (44) ◽  
pp. e8312 ◽  
Author(s):  
Marie Fukami ◽  
Takeshi Iwase ◽  
Kentaro Yamamoto ◽  
Eimei Ra ◽  
Kenta Murotani ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Diurnal Variation ◽  
Optic Nerve Head ◽  
Healthy Subjects ◽  
Laser Speckle ◽  
Laser Speckle Flowgraphy ◽  
Pulse Waveform

scholarly journals Characterization of laser speckle flowgraphy pulse waveform parameters for the evaluation of the optic nerve head and retinal circulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nobuko Enomoto ◽  
Ayako Anraku ◽  
Goji Tomita ◽  
Aiko Iwase ◽  
Takashi Sato ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Structural Parameters ◽  
Laser Speckle ◽  
Smoking History ◽  
Laser Speckle Flowgraphy ◽  
Pulse Waveform ◽  
Flow Acceleration ◽  
Ocular Circulation ◽  
Systemic Factors

AbstractTo characterize laser speckle flowgraphy (LSFG) pulse waveform parameters for ocular circulation evaluation, a multicenter, prospective, cross-sectional study was conducted in 111 eyes of 86 healthy Japanese individuals. Optic nerve head (ONH) tissue-area, vessel-area mean blur rate (MT and MV, respectively), and MT and MV pulse waveform parameters were obtained using LSFG and ONH structural parameters using planimetry. Multivariate linear mixed-effects modeled regression analysis identified factors contributing to MT- or MV-waveforms using age, gender, smoking history, body mass index, systolic and diastolic blood pressure, heart rate, intraocular pressure, axial length, disc, rim, and β-peripapillary atrophy areas, MT or MV, central retinal artery, and vein equivalents (CRAE and CRVE) as explanatory variables. MT- and MV-waveforms significantly correlated with one or more systemic factors, consistent with previous studies. Following confounding factor adjustment, MT-Skew significantly negatively correlated with β-PPA area (P = 0.026); MT- and MV-flow acceleration index positively correlated with CRAE, MT, and MV (P = 0.041–< 0.001), compatible with these parameters’ observed correlations to systemic factors. Significantly negative correlations of the blowout score and acceleration time index to CRAE partly conflicted with their correlations to systemic factors, and other waveform parameters showed little correlation to ocular factors. Thus, Skew and flow acceleration index assisted the in vivo ocular circulation characterization.

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.

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