1. Articles from Takehiro Yamashita

    1-18 of 18
    1. Quantitative analyses of diameter and running pattern of choroidal vessels in central serous chorioretinopathy by en face images

      Quantitative analyses of diameter and running pattern of choroidal vessels in central serous chorioretinopathy by en face images

      This study was to investigate the choroidal vessels in eyes with central serous chorioretinopathy (CSC) quantitatively. We studied 41 CSC eyes and their fellow eyes, and 41 normal eyes of 41 age-adjusted individuals. En-face optical coherence tomography image of the top 25% slab of Haller’s layer was analyze. The mean vessel area, vessel length, and vessel diameter were calculated. The running pattern of the vessels was quantified and used to determine the degree of symmetry, the “symmetry index”. The vessel area of CSC eyes was not significantly different from that of fellow eyes but significantly larger than that of ...

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      Mentions: Taiji Sakamoto
    2. Regional Differences of Choroidal Structure Determined by Wide-Field Optical Coherence Tomography

      Regional Differences of Choroidal Structure Determined by Wide-Field Optical Coherence Tomography

      Purpose : To compare the submacular to the perimacular choroidal structure in images obtained by wide-field optical coherence tomography (OCT). Methods : Thirty eyes of 30 healthy volunteers (15 men) were studied. Twelve wide-field radial circumferential scans were recorded with enhanced depth imaging OCT from the macular and perimacular zones. The sizes of the luminal and stromal areas of the choroid were determined. The two zones were subdivided into the superior, inferior, nasal, and temporal sectors. The total choroidal area, the luminal and stromal areas, and the luminal ratio of each sector were compared. Results : All of the choroidal structural parameters analyzed ...

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    3. Semi-automated software to measure luminal and stromal areas of choroid in optical coherence tomographic images

      Semi-automated software to measure luminal and stromal areas of choroid in optical coherence tomographic images

      Purpose To determine the capabilities of “EyeGround” software in measuring the choroidal cross sectional areas in optical coherence tomographic (OCT) images. Study design Cross sectional, prospective study. Methods The cross-sectional area of the subfoveal choroid within a 1500 µm diameter circle centered on the fovea was measured both with and without using the EyeGround software in the OCT images. The differences between the evaluation times and the results of the measurements were compared. The inter-rater, intra-rater, inter-method agreements were determined. Results Fifty-one eyes of 51 healthy subjects were studied: 24 men and 27 women with an average age of 35 ...

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      Mentions: Taiji Sakamoto
    4. Correlations between local peripapillary choroidal thickness and axial length, optic disc tilt, and papillo-macular position in young healthy eyes

      Correlations between local peripapillary choroidal thickness and axial length, optic disc tilt, and papillo-macular position in young healthy eyes

      Optical coherence tomography (OCT) has made it possible for clinicians to measure the peripapillary choroidal thickness (ppCT) noninvasively in various ocular diseases. However, the ocular factors associated with the ppCT have not been conclusively determined. The purpose of this study was to determine the relationship between the local ppCT and the axial length, optic disc tilt, and the angle of the papillo-macular position (PMP) in healthy eyes. This was a prospective, observational cross-sectional study of 119 right eyes of 119 healthy Japanese volunteers. The ppCT was manually measured at eight sectors around the optic disc using the B-scan images of ...

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    5. Structural Changes of Inner and Outer Choroid in Central Serous Chorioretinopathy Determined by Optical Coherence Tomography

      Structural Changes of Inner and Outer Choroid in Central Serous Chorioretinopathy Determined by Optical Coherence Tomography

      Purpose To determine the structural changes of the choroid in eyes with central serous chorioretinopathy (CSC) by enhanced depth imaging optical coherence tomography (EDI-OCT). Methods A retrospective comparative study was performed at two academic institutions. Forty eyes with CSC, their fellow eyes, and 40 eyes of age-matched controls were studied. Subfoveal cross sectional EDI-OCT images were recorded, and the hypo reflective and hyperreflective areas of the inner and outer choroid in the EDI-OCT images were separately measured. The images were analyzed by a binarization method to determine the sizes of the hyporeflective and hyperreflective areas. Results In the inner choroid ...

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      Mentions: Taiji Sakamoto
    6. Impact of final kissing balloon inflation on vessel healing following drug-eluting stent implantation: Insight from the optical coherence tomography sub-study of the J-REVERSE trial

      Impact of final kissing balloon inflation on vessel healing following drug-eluting stent implantation: Insight from the optical coherence tomography sub-study of the J-REVERSE trial

      Background We sought to clarify the impact of final kissing inflation (FKI) after single stenting of bifurcation lesions on vessel healing. Methods From the J-REVERSE registry enrolling 303 bifurcation lesions treated with provisional single stenting using sirolimus- (SES) or everolimus-eluting stent (EES), 65 lesions treated with ( n = 30) and without ( n = 35) FKI underwent 9-month follow-up optical coherence tomography. Average stent eccentricity index (SEI: minimum/maximum stent diameter) and neointimal unevenness score (NUS: maximum/average neointimal thickness of the same cross-section) for the proximal, bifurcation, and distal segments were compared between FKI and non-FKI groups. Results At the proximal segment ...

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    7. Differences in Vessel Healing Between Sirolimus- and Everolimus-Eluting Stent Implantation for Bifurcation Lesions: The J-REVERSE Optical Coherence Tomography Substudy

      Differences in Vessel Healing Between Sirolimus- and Everolimus-Eluting Stent Implantation for Bifurcation Lesions: The J-REVERSE Optical Coherence Tomography Substudy

      Background We aimed to clarify the differences in vessel healing after stenting of bifurcation lesions using sirolimus-eluting stents (SESs) or everolimus-eluting stents (EESs). Methods J apanese R egistry Study in Comparison Between Ever olimus-Eluting Stent and S irolimus- E luting Stent for the Bifurcation Lesion (J-REVERSE) is a prospective multicentre registry of 303 bifurcation lesions that were treated with provisional SES or EES with or without final kissing inflation. The first 115 lesions at selected study sites were predefined for inclusion in the optical coherence tomography (OCT) substudy, and 9-month follow-up OCT was conducted in 64 lesions (SES, n = 18 ...

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    8. Differences in Vessel Healing between Sirolimus- and Everolimus-eluting Stent Implantation for Bifurcation Lesions: The J-REVERSE OCT Sub-study

      Differences in Vessel Healing between Sirolimus- and Everolimus-eluting Stent Implantation for Bifurcation Lesions: The J-REVERSE OCT Sub-study

      Background We aimed to clarify the differences in vessel healing after stenting for bifurcation lesions using sirolimus-eluting stent (SES) or everolimus-eluting stent (EES). Methods J-REVERSE is a prospective multicenter registry of 303 bifurcation lesions that were treated with provisional SES or EES with or without final kissing inflation. The first 115 lesions at selected study sites were predefined for inclusion in the optical coherence tomography (OCT) sub-study and 9-month follow-up OCT was conducted in 64 lesions (SES: n = 18, EES: n = 46). In addition to standard OCT parameters, stent eccentricity index (SEI; minimum divided by the maximum stent diameter), neointimal ...

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    9. Blood Components and OCT Reflectivity Evaluated in Animal Model

      Blood Components and OCT Reflectivity Evaluated in Animal Model

      Background/purpose : To see the relationship between blood components and optical coherence tomography ( OCT ) reflectivity using an animal model in which the aqueous humor was substituted by different experimental solutions without changing the integrity of the retina. Materials and methods : The aqueous humor of an enucleated swine eye was replaced with plasma obtained from healthy volunteers. The OCT reflectivity of the anterior chamber filled with each plasma was calculated from individual OCT images, and was expressed by an arbitrary unit (AU). The concentration of blood components such as cholesterol, hemoglobin (Hb) and bilirubin of each individual was measured, and the ...

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      Mentions: Taiji Sakamoto
    10. INDIVIDUALIZED, SPECTRAL DOMAIN-OPTICAL COHERENCE TOMOGRAPHY–GUIDED FACEDOWN POSTURING AFTER MACULAR HOLE SURGERY: Minimizing Treatment Burden and Maximizing Outcome

      INDIVIDUALIZED, SPECTRAL DOMAIN-OPTICAL COHERENCE TOMOGRAPHY–GUIDED FACEDOWN POSTURING AFTER MACULAR HOLE SURGERY: Minimizing Treatment Burden and Maximizing Outcome

      Purpose: To evaluate the individualized, optical coherence tomography-guided facedown posturing after macular hole (MH) surgery in minimizing the burden and maximizing outcome. Methods: A retrospective comparative study. One hundred and seven consecutive eyes with an MH (<500 μ m) received vitrectomy and gas tamponade. After surgery, optical coherence tomography examination was performed from 6 hours to postoperative Day 2. In Group A, with a pro re nata posturing protocol, the duration of facedown posturing was determined from the optical coherence tomography findings. Group A was subdivided as follows: Group A1, facedown posturing required postoperatively and Group A2, no posturing required. When ...

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    11. Choroidal Structure in Normal Eyes and After Photodynamic Therapy Determined by Binarization of Optical Coherence Tomographic Images

      Choroidal Structure in Normal Eyes and After Photodynamic Therapy Determined by Binarization of Optical Coherence Tomographic Images

      Purpose. To determine changes in choroidal structure by binarization of optical coherence tomographic (OCT) images. Methods. Choroidal images were recorded by enhanced depth imaging OCT. The subfoveal choroidal images were analyzed, and the luminal and interstitial areas were converted to binary images by the Niblack method. The interrater, intrarater, and intersession agreements of the binary images were determined for healthy eyes. In eyes with age-related macular degeneration (AMD), the binary images of the choroid before photodynamic therapy (PDT) were compared to those after PDT. The untreated fellow eyes were studied as controls. Results. In healthy eyes, the average ratio of ...

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      Mentions: Taiji Sakamoto
    12. Comparisons of Choroidal Thickness of Normal Eyes Obtained by Two Different Spectral-Domain OCT Instruments and One Swept-Source OCT Instrument

      Comparisons of Choroidal Thickness of Normal Eyes Obtained by Two Different Spectral-Domain OCT Instruments and One Swept-Source OCT Instrument

      Purpose. We compared the subfoveal choroidal thickness (SFCT) measured on the images obtained by two spectral-domain optical coherence tomographic (SD-OCT) instruments and one swept-source OCT (SS-OCT) instrument. Methods. A cross-sectional, prospective noninterventional study was done in which SFCT was measured in the images obtained by two SD-OCT instruments; Heidelberg Spectralis-OCT (Spectralis-SD-OCT) and Topcon 3D OCT-1000 Mark II (Topcon-SD-OCT). Images also were obtained with SS-OCT Atlantis DRI OCT-1 (DRI-SS-OCT). After manual segmentation, the measurements were made using the calipers embedded in each instrument. The intrarater, interrater, and intermachine agreements were assessed. Results. We studied 35 subjects. The intrarater correlation coefficient (95 ...

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    13. Association between retinal thickness of 64 sectors in posterior pole determined by optical coherence tomography and axial length and body height

      Association between retinal thickness of 64 sectors in posterior pole determined by optical coherence tomography and axial length and body height

      PURPOSE: To determine a significant correlation between the retinal thickness (RT) in 64 cells or sectors of the posterior pole and the axial length (AL) and the body height (BH). METHODS: A prospective, observational cross sectional study of 64 right eyes of 64 healthy volunteers (mean age 26.0 ± 4.5 years; range, 22 to 39 years). The RT within the central 24° area was measured in the Spectralis spectral domain-optical coherence tomographic (SD-OCT) images. The correlations between the RT and the AL or the BH were determined by linear regression analyses. RESULTS: The mean ± standard deviation of the AL ...

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      Mentions: Taiji Sakamoto
    14. Correlation Between Reflectivity of Subretinal Fluid in OCT Images and Concentration of Intravitreal VEGF in Eyes With Diabetic Macular Edema

      Correlation Between Reflectivity of Subretinal Fluid in OCT Images and Concentration of Intravitreal VEGF in Eyes With Diabetic Macular Edema

      Purpose. The reflectivity of optical coherence tomographic (OCT) images has been used to evaluate retinal diseases. The purpose of our study was to determine whether a significant correlation exists between the reflectivity of the subretinal fluid (SRF) and the concentration of intravitreal cytokines in eyes with diabetic macular edema (DME). Methods. A retrospective comparative study was done of eyes with DME with SRF before vitrectomy. The reflectivity of the SRF was determined from the OCT images. Vitreous samples were collected during vitrectomy, and analyzed for the concentrations of VEGF, IL-6, and IL-8. To determine the factors in the SRF that ...

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      Mentions: Taiji Sakamoto
    15. Relationship between position of peak retinal nerve fiber layer thickness and retinal arteries on sectoral retinal nerve fiber layer thickness

      Relationship between position of peak retinal nerve fiber layer thickness and retinal arteries on sectoral retinal nerve fiber layer thickness

      PURPOSE: To determine the relationship between the position of the peak of the retinal nerve fiber layer (RNFL) thickness and the retinal arteries, axial length (AL), and sectoral RNFL thickness in healthy eyes. METHODS: A prospective, observational cross-sectional study (registration number, UMIN000006040) of 50 healthy right eyes (mean age 25.8 ± 3.7 years) was performed. The RNFL thickness was measured by optical coherence tomography in twelve 30-degrees sectors (clock hours) around the optic disc. The RNFL nasal-superior-temporal-inferior-nasal curves and fundus photographs were used to measure the angles between the supra-temporal and the infra-temporal peak RNFL positions (peak angle) and ...

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      Mentions: Taiji Sakamoto
    16. Early Imaging of Macular Hole Closure: A Diagnostic Technique and Its Quality for Gas-Filled Eyes with Spectral Domain Optical Coherence Tomography

      Early Imaging of Macular Hole Closure: A Diagnostic Technique and Its Quality for Gas-Filled Eyes with Spectral Domain Optical Coherence Tomography

      Background/Aims: This study was conducted to establish a reliable method to determine macular hole (MH) closure of gas-filled eyes. Method: 21 consecutive eyes with MH underwent vitrectomy with gas tamponade, and spectral domain optical coherence tomography (SD-OCT) was performed using our diagnostic technique. The quality of OCT images was rated as signal strength (SS) and evaluated by masked observers. Results: The quality to determine MH closure (SS ≥4) was sufficient in all eyes. In addition, SD-OCT images (SS ≥6) obtained from 16/21 eyes showed detailed retinal structures including the inner segment/outer segment line. The next day after ...

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    17. Comparison of Foveal Microstructure Imaging with Different Spectral Domain Optical Coherence Tomography Machines

      Comparison of Foveal Microstructure Imaging with Different Spectral Domain Optical Coherence Tomography Machines

      Purpose: To investigate the reproducibility of imaging the foveal microstructures of healthy eyes with 3 spectral domain optical coherence tomography (SD-OCT) machines: Cirrus (Carl Zeiss Meditec Inc.), Spectralis (Heidelberg Engineering), and Topcon (Topcon 3D OCT-1000 Mark II).Design: Cross-sectional, prospective, noninterventional study.Participants: Images were obtained for 50 eyes of 50 healthy undilated volunteers without ocular pathology in a clinical setting.Methods: The fovea of all subjects was imaged using Cirrus, Spectralis, and Topcon.Main Outcome Measures: Among the 4 hyperreflective bands in the outer subfovea on SD-OCT imaging, the innermost band (external limiting membrane [ELM] band), the second innermost ...

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    18. Repeatability and Reproducibility of Subfoveal Choroidal Thickness in Normal Eyes of Japanese Using Different SD-OCT Devices

      Repeatability and Reproducibility of Subfoveal Choroidal Thickness in Normal Eyes of Japanese Using Different SD-OCT Devices

      Purpose. To compare subfoveal choroidal thickness (SCT) measurements of three different commercially available spectral-domain optical coherence tomography instruments with healthy eyes of Japanese. Methods. A prospective, cross-sectional study was performed at a single institution. SCT of the right eye of 43 normal subjects was measured using three different SD-OCTs: Heidelberg Spectralis-OCT (Spectralis), Cirrus HD-OCT (Cirrus), and Topcon 3D OCT-1000 Mark II (Topcon). Two separate measurements were performed for the same eye with a maximum by a single examiner. SCT was defined as the distance from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction. After manual ...

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    1-18 of 18
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    Repeatability and Reproducibility of Subfoveal Choroidal Thickness in Normal Eyes of Japanese Using Different SD-OCT Devices Comparison of Foveal Microstructure Imaging with Different Spectral Domain Optical Coherence Tomography Machines Early Imaging of Macular Hole Closure: A Diagnostic Technique and Its Quality for Gas-Filled Eyes with Spectral Domain Optical Coherence Tomography Relationship between position of peak retinal nerve fiber layer thickness and retinal arteries on sectoral retinal nerve fiber layer thickness Correlation Between Reflectivity of Subretinal Fluid in OCT Images and Concentration of Intravitreal VEGF in Eyes With Diabetic Macular Edema Association between retinal thickness of 64 sectors in posterior pole determined by optical coherence tomography and axial length and body height Comparisons of Choroidal Thickness of Normal Eyes Obtained by Two Different Spectral-Domain OCT Instruments and One Swept-Source OCT Instrument INDIVIDUALIZED, SPECTRAL DOMAIN-OPTICAL COHERENCE TOMOGRAPHY–GUIDED FACEDOWN POSTURING AFTER MACULAR HOLE SURGERY: Minimizing Treatment Burden and Maximizing Outcome Differences in Vessel Healing between Sirolimus- and Everolimus-eluting Stent Implantation for Bifurcation Lesions: The J-REVERSE OCT Sub-study Differences in Vessel Healing Between Sirolimus- and Everolimus-Eluting Stent Implantation for Bifurcation Lesions: The J-REVERSE Optical Coherence Tomography Substudy Customized Slab-Segmentation Method for Projection-Artifact Elimination in Best Vitelliform Macular Dystrophy: A Swept-Source Optical Coherence Tomography Angiography Study Corneal Epithelial Thickness Profile in Healthy Portuguese Children by High-Definition Optical Coherence Tomography