Publications by authors named "Tomoaki Shiba"

This study aimed to investigate the feasibility of utilizing noninvasive ocular blood flow measurements as potential indicators of systemic circulation in rabbits experiencing hemorrhagic shock. Using Laser speckle flowgraphy, ocular blood flow indices, relative flow volume (RFV), and mean blur rate in the choroidal area (MBR-CH) were assessed in New Zealand White rabbits (n = 10) subjected to controlled blood removal and return. Hemodynamic parameters and biochemical markers were monitored alongside ocular circulation during blood removal and return phases.

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We aimed to perform superpixel segmentation of ocular blood flow maps obtained using laser speckle flowgraphy (LSFG) and investigate the effects of systemic parameters such as body weight, height, and sex on ocular blood flow resistivity. We studied 757 healthy participants (583 men, 174 women). We calculated the average beat strength over mean blur rate (BOM) as a LSFG resistivity index, as a function of age and sex using ordinary regions of interest (ROI) centered on the optic nerve head (ONH), the retinal vessels region and tissue around the ONH, and the choroid (CHD).

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Purpose: We examined the effects of aging and exercise habits on the ocular blood flow (OBF) and its profiles throughout the optic nerve head region and choroidal area. We hypothesized that exercise habits reduce the stiffness of vessels in the ocular circulation, which generally increases with aging.

Methods: Participants in a medical checkup program (698 males and 192 females aged 28 to 80 years) were categorized into 2 groups (with and without exercise habits) based on participant self-reporting and the definition of the Ministry of Health, Labor and Welfare of Japan (MHLW).

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Purpose: To determine the characteristics of the laterality of the ocular microcirculation parameters obtained from laser speckle flowgraphy (LSFG) in the optic nerve head (ONH).

Subjects And Methods: We reanalyzed a total of 240 healthy subjects (169 men, 71 women) who had participated in a medical checkup program. We analyzed the average mean blur rate (MBR), maximum MBR (Max-MBR), minimum MBR (Min-MBR), and area ratio of the blood stream (ARBS).

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Purpose: To evaluate continuous variations of ocular microcirculation by laser speckle flowgraphy and those of regional stiffening by pulse wave velocity (PWV) and vascular resistance under systemic adrenaline administration in rabbits.

Methods: Six 16-week-old male rabbits were evaluated. The mean blur rates in the retinal vessel (MBR-RV) and choroid (MBR-CH) were measured.

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Purpose: To clarify the continuous changes in the retinal vessels' and choroid's microcirculation during hemorrhagic shock and resuscitation in a rabbit model.

Methods: Hemorrhagic shock by the removal of blood (30 mL) and resuscitation by a blood-return technique was induced in anesthetized male New Zealand White rabbits (n = 10). We evaluated the retinal vessel blood flow (relative flow volume: RFV) and choroidal blood flow (mean blur rate in the choroid area: MBR-CH) by laser speckle flowgraphy (LSFG), with simultaneous measurements of systemic hemodynamics and laboratory parameters.

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To 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.

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Article Synopsis
  • The study aimed to investigate how ocular and systemic factors influence glaucoma measurements using laser speckle flowgraphy (LSFG) in normal Japanese individuals.
  • A multicenter approach evaluated the optic nerve head’s blood flow and related structural parameters, applying statistical analysis to identify key contributing factors.
  • Results indicated specific correlations between blood flow metrics and factors such as mean arterial pressure, disc area, age, and axial length, highlighting the need to adjust for these factors in interindividual comparisons of ocular blood flow.
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We investigated gender differences in the optic nerve head (ONH) microcirculation status in association with obstructive sleep apnea (OSA) by using laser speckle flowgraphy (LSFG). We evaluated 150 men (60.5 ± 11.

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The 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.

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Potential differences in the nature of the influences of aging and gender on the optic nerve head (ONH) microcirculation, using laser speckle flowgraphy (LSFG) were evaluated. We studied 908 healthy subjects (men = 701, age: 50.0 ± 9.

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Purpose: To evaluate whether the features of sleep-disordered breathing (SDB) are stronger independent factors for proliferative diabetic retinopathy (PDR) compared to the incidence of metabolic syndrome (MetS) and the number of its individual components.

Methods: We studied a cross-sectional total of 132 patients with type 2 diabetes. Thirty-nine patients had non-proliferative diabetic retinopathy (NPDR) and 93 patients had PDR.

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Purpose: Detecting primary breaks and confirming detachment preoperatively are important. Lincoff stated that retinal detachments progress according to gravity; his law has become popular. We evaluated Lincoff's law with a slight modification to determine whether it remains suitable for present cases independent of refractive error and previous cataract surgery.

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Purpose: To determine: (1) whether variables of a pulse wave form analysis of ocular microcirculation shown by laser speckle flowgraphy (LSFG) correlate with left ventricular (LV) systolic dysfunction and (2) whether these variables correlate with LV diastolic dysfunction in subjects without LV systolic dysfunction as assessed by echocardiography.

Methods: We studied 200 consecutive subjects. LV systolic dysfunction has been determined to be present when the LV ejection fraction was < 50%.

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Purpose: To determine the impact that end-stage kidney disease (ESKD) has on ocular microcirculation in the optic nerve head (ONH) and choroid area shown by laser speckle flowgraphy (LSFG).

Methods: We studied 24 consecutive Japanese patients with ESKD who visited the department of Nephrology at our hospital and 55 age- and gender-matched subjects who had undergone polysomnography. The mean blur rates (MBRs) in vessels (MBR-Vessel), in the tissue (MBR-Tissue), throughout the ONH (MBR-All), and throughout the choroid (MBR-Choroid) were analyzed.

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Purpose: To evaluate the relationship between ocular blood flow, expressed as mean blur rate (MBR) by laser speckle flowgraphy, and intravitreal bevacizumab (IVB) therapy in neonates with retinopathy of prematurity (ROP).

Methods: This was a case series study of 4 neonates with ROP under sedation before and after IVB and evaluated 8 eyes, in which the circulation could be measured three times consecutively. We performed optic nerve head blood flow measurement and fluorescein angiography (FA) before and 1 week after treatment.

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To evaluate the relationships between parameters of the pulsatile flow form in the optic nerve head shown by laser speckle flowgraphy (LSFG) and the left ventricular (LV) end-diastolic pressure and mass obtained by echocardiography. We cross sectional analyzed the cases of 175 subjects who had undergone polysomnography. Standard M-mode two-dimensional color Doppler imaging was performed to evaluate the E/e' ratio (which represents the LV end-diastolic pressure) and LV mass.

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Purpose: To clarify whether the incidence of metabolic syndrome (MetS) and the overlap of MetS components are affecting the ocular circulation shown by laser speckle flowgraphy (LSFG).

Materials And Methods: We studied 76 consistent patients. Blowout score (BOS) and blowout time (BOT), which are the pulse waveform analysis parameters, and mean blur rate (MBR) using LSFG in the optic nerve head (ONH) and choroid were evaluated.

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Purpose: To evaluate the relationships between optic nerve head blood flow, expressed as mean blur rate (MBR) measured by laser speckle flowgraphy (LSFG), and photocoagulation therapy in neonates with retinopathy of prematurity (ROP).

Study Design: Case series study.

Methods: We studied 5 ROP neonates either during sleep or under sedation both before and after photocoagulation, and evaluated 8 eyes in which the circulation could be measured three times consecutively.

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Purpose: We used a Laser speckle flowgraphy (LSFG)-micro system to examine the relationship between ocular blood flow and retinal vascular endothelial growth factor (VEGF) at retinopathy onset in oxygen-induced ischemic retinopathy (OIR) model rats.

Methods: Sixteen 50/10 OIR rats were compared with 17 control rats reared in room air. In postnatal day 14 (P14) and P18 rats, we measured and analyzed the left eye's mean blur rate (MBR) by setting a rubber band on the optic nerve head center, using the LSFG-Micro.

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Purpose: To determine whether differences or variation of blood flow in the ONH are independent risk factors for CAD.

Methods: We studied 144 consecutive patients whose ocular blood flow in the ONH was measured in the evening and morning by LSFG. We analyzed the MBR throughout the ONH (MBR-A) and in the tissue (MBR-T) and vessels (MBR-V) in the ONH.

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Background: The dilation of veins and tortuosity of arteries that occur in retinopathy of prematurity (ROP) are improved by therapy, and thus posttherapy changes in ocular circulation are also conceivable. We report a case of ROP in which we were able to measure the ocular circulation before and after photocoagulation therapy, using a laser speckle flowgraphy (LSFG) system that is modified for neonates.

Case Report: A female infant was born at 25 weeks' gestation with a birth weight of 808 g.

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Purpose: To investigate the short-term effects of 2 new secretagogue eye drops for dry eye, 3% diquafosol tetrasodium ophthalmic solution (diquafosol) and 2% rebamipide ophthalmic suspension (rebamipide), on the concentration of mucin 5AC (MUC5AC) in rabbit tear fluid and conjunctival goblet cells.

Methods: One dose of artificial tears, diquafosol or rebamipide, was instilled into 8 eyes of Japanese white rabbits. MUC5AC concentration in the tear fluid was examined using the enzyme-linked immunosorbent assay 15 min after instillation and compared with 8 untreated controls.

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. To determine the correlations among the mean blur rate (MBR) in the optic nerve head (ONH) shown by laser speckle flowgraphy (LSFG), retinal arteriosclerosis, and the circulation time obtained by fluorescein angiography (FA). .

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