1. Articles from Marco Yu

    1-22 of 22
    1. Comparison of Two Novel Swept-Source OpticalCoherence Tomography Devices to A PartialCoherence Interferometry-Based Biometer

      Comparison of Two Novel Swept-Source OpticalCoherence Tomography Devices to A PartialCoherence Interferometry-Based Biometer

      Purpose To evaluate the repeatability and agreement of cornea and biometry measurements obtained with two swept-source optical coherence tomography (SSOCT) and a partial coherence interferometry-based device. METHODS This is a cross-sectional study. Forty-eight eyes of 48 patients had three consecutive measurements for ANTERION (Heidelberg Engineering, Germany), CASIAII (Tomey, Japan) and IOLMaster500 (Carl Zeiss Meditec, USA) on the same visit. Mean keratometry (Km), central cornea thickness (CCT), anterior chamber depth (ACD) and axial length (AL) were recorded. Corneal astigmatic measurements were converted into vector components – J0 and J45. Intra-device repeatability and agreements of measurements amongst the devices were evaluated using repeatability ...

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    2. Utilisation of poor-quality optical coherence tomography scans: adjustment algorithm from the Singapore Epidemiology of Eye Diseases (SEED) study

      Utilisation of poor-quality optical coherence tomography scans: adjustment algorithm from the Singapore Epidemiology of Eye Diseases (SEED) study

      Purpose To evaluate the effect of signal strength (SS) on optical coherence tomography (OCT) parameters, and devise an algorithm to adjust the effect, when acceptable SS cannot be obtained. Methods 5085 individuals (9582 eyes), aged ≥40 years from the Singapore Epidemiology of Eye Diseases population-based study were included. Everyone underwent a standardised ocular examination and imaging with Cirrus HD-OCT. Effect of SS was evaluated using multiple structural breaks linear mixed-effect models. Expected change for increment in SS between 4 and 10 for individual parameter was calculated. Subsequently we devised and evaluated an algorithm to adjust OCT parameters to higher SS ...

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    3. Quantitative OCT angiography of the retinal microvasculature and choriocapillaris in highly myopic eyes with myopic macular degeneration

      Quantitative OCT angiography of the retinal microvasculature and choriocapillaris in highly myopic eyes with myopic macular degeneration

      Purpose: To quantify retinal and choriocapillaris (CC) microvasculature in highly myopic (HM) eyes with myopic macular degeneration (MMD) using swept-source optical coherence tomography angiography (SS-OCTA). Methods: 162 HM eyes (spherical equivalent ≤ -6.0 dioptres or axial length (AL) ≥26.5 mm) from 98 participants were enrolled, including 60 eyes (37.0%) with tessellated fundus, 54 eyes (33.3%) with peripapillary diffuse chorioretinal atrophy (PDCA), 27 eyes (16.7%) with macular diffuse chorioretinal atrophy (MDCA) and 21 eyes (13.0%) with patchy or macular atrophy. PLEX Elite 9000 SS-OCTA was performed to obtain perfusion densities (PD) of the superficial and deep ...

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    4. Anterior chamber angle imaging with swept-source optical coherence tomography: comparison between CASIAII and ANTERION

      Anterior chamber angle imaging with swept-source optical coherence tomography: comparison between CASIAII and ANTERION

      This study compared the test-retest variabilities and measurement agreement of anterior chamber angle (ACA) dimensions measured by two anterior segment swept-source optical coherence tomography (SS-OCT)-the ANTERION (Heidelberg Engineering, Heidelberg, Germany) and CASIAII (Tomey, Nagoya, Japan). Thirty-eight subjects, 18 patients with primary angle closure and 20 healthy participants with open angles, were included. The mean age was 54.7 ± 15.8 years (range: 26-75 years). One eye of each subject was randomly selected for anterior segment imaging by ANTERION and CASIAII, using the same scan pattern (6 evenly spaced radial scans across the anterior segment for three times) in the ...

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    5. Repeatability and Agreement of a Swept-Source Optical Coherence Tomography–Based Biometer IOLMaster 700 Versus a Scheimpflug Imaging–Based Biometer AL-Scan in Cataract Patients

      Repeatability and Agreement of a Swept-Source Optical Coherence Tomography–Based Biometer IOLMaster 700 Versus a Scheimpflug Imaging–Based Biometer AL-Scan in Cataract Patients

      Purpose: To compare the repeatability and agreement between a swept-source biometer and a Scheimpflug biometer in cataract patients. Methods: Three consecutive measurements were obtained using a swept-source biometer (IOLMaster 700) and a Scheimpflug biometer (AL-Scan) in 52 eyes of 52 patients. Keratometry, central corneal thickness (CCT), anterior chamber depth (ACD), axial length , and white-to-white (WTW) distance were recorded. Astigmatism values were transformed into vector components of J0 and J45. Intraoperator repeatability was analyzed using intraclass correlation coefficients (ICCs) and reproducibility coefficients (RCs). Agreement of measurements between the two devices was evaluated using the Bland–Altman method. Results: The IOLMaster 700 ...

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    6. Comparison of corneal measurements in keratoconus using swept-source optical coherence tomography and combined Placido–Scheimpflug imaging

      Comparison of corneal measurements in keratoconus using swept-source optical coherence tomography and combined Placido–Scheimpflug imaging

      Purpose The aim of this study was to provide a comprehensive comparison of reliability of corneal topographic measurements in keratoconic eyes using swept-source optical coherence tomography (OCT) and a combined Placido–Scheimpflug imaging. Methods A total of 30 eyes of 30 patients were included. The mean age was 31.2 ± 8.4 years. Two consecutive topographic measurements were obtained for one eye of each patient using swept-source OCT (CASIA) and combined Placido–Scheimpflug imaging (TMS-5). Test–retest reliability of CASIA and TMS-5 measurements including central corneal thickness (CCT) and thinnest corneal thickness (TCT), keratometry at steep (Ks) and flat (Kf ...

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    7. Impact of segmentation errors and retinal blood vessels on retinal nerve fibre layer measurements using spectral-domain optical coherence tomography

      Impact of segmentation errors and retinal blood vessels on retinal nerve fibre layer measurements using spectral-domain optical coherence tomography

      Purpose To investigate the impact of retinal blood vessels and retinal nerve fibre layer (RNFL) segmentation errors on RNFL measurement. Methods One eye of 180 subjects (60 normal, 66 mild-to-moderate and 54 advanced glaucoma subjects) was randomly selected for RNFL imaging with a spectral-domain OCT. The boundaries of the RNFL detected by the instrument software were checked, and the segmentation errors were corrected by a customized computer program. The differences in average and regional RNFL thicknesses (RNFLT) before and after the correction were analysed to determine the frequency of segmentation error (defined as an absolute difference in average RNFLT >5 ...

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    8. Stromal Bed Thickness Measurement During Laser in Situ Keratomileusis Using Intraoperative Optical Coherence Tomography

      Stromal Bed Thickness Measurement During Laser in Situ Keratomileusis Using Intraoperative Optical Coherence Tomography

      Purpose: The aim of this study was to compare repeatability and agreement of stromal bed thickness (SBT) measurements with intraoperative spectral domain optical coherence tomography (SD-OCT) and ultrasound pachymetry (USP). Methods: The SBT was measured in 14 eyes of 14 patients during femtosecond laser in situ keratomileusis (LASIK). Intraoperative SD-OCT was positioned on the eye to acquire images after creation of LASIK flaps. Patients were then asked to sit in front of a swept-source optical coherence tomography (SS-OCT) for measurements. Subsequently, LASIK flaps were lifted and SBT was measured with USP. Three readings were obtained with each instrument. Repeatability of ...

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    9. Longitudinal Evaluation of Posterior Corneal Elevation after Laser Refractive Surgery Using Swept-Source Optical Coherence Tomography

      Longitudinal Evaluation of Posterior Corneal Elevation after Laser Refractive Surgery Using Swept-Source Optical Coherence Tomography

      Purpose To investigate the change in posterior corneal elevation up to 1 year after myopic femtosecond-assisted LASIK and photorefractive keratectomy (PRK). Design Prospective, longitudinal, comparative study. Participants Patients undergoing femtosecond-assisted LASIK or PRK. Methods Corneal imaging was performed using swept-source optical coherence tomography at baseline and at each postoperative follow-up. A 2-way analysis of variance model with repeated measures and a linear mixed effect model were used to compare the differences in posterior corneal elevation between LASIK and PRK at different points after adjusting for the preoperative spherical equivalent (SEQ), central corneal thickness (CCT), thinnest corneal thickness (TCT), residual bed ...

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    10. Intraoperative Pachymetry Using Spectral-Domain Optical Coherence Tomography during Accelerated Corneal Collagen Crosslinking

      Intraoperative Pachymetry Using Spectral-Domain Optical Coherence Tomography during Accelerated Corneal Collagen Crosslinking

      <p>accelerated corneal crosslinking (CXL). Methods. Intraoperative pachymetry was performed using SDOCT and ultrasound pachymetry (USP) in 6 eyes of 6 patients with keratoconus. Pachymetry readings were obtained at baseline, after epithelium removal and after 30 minutes of riboflavin instillation. SDOCT measurements of eyes with and without lid speculum during riboflavin instillation were compared. Results. There was no statistically significant difference in central corneal thickness (CCT) measurements between SDOCT and USP (

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    11. Corneal thickness and elevation measurements using swept source optical coherence tomography and slit scanning topography in normal and keratoconic eyes

      Corneal thickness and elevation measurements using swept source optical coherence tomography and slit scanning topography in normal and keratoconic eyes

      Background Optical coherence tomography is being used increasingly for corneal measurements. The current study compared corneal thickness and corneal elevation using SS-OCT (Casia, Tomey, Nagoya, Japan) and slit scanning topography (Orbscan IIz, Bausch & Lomb, Rochester, New York). Design Prospective study Participants 41 normal and 46 keratoconus subjects Methods All eyes were imaged using SS-OCT and slit scanning tomography during the same visit. Mean central (CCT) and thinnest (TCT) corneal thickness and best-fit sphere (BFS) measurements were compared between the instruments. Corneal thickness was also measured with ultrasound pachymetry (USP). Main outcome measures Agreement of measurements between SS-OCT and scanning slit ...

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    12. Anterior Chamber Angle Imaging with Swept-Source Optical Coherence Tomography: Measuring Peripheral Anterior Synechia in Glaucoma

      Anterior Chamber Angle Imaging with Swept-Source Optical Coherence Tomography: Measuring Peripheral Anterior Synechia in Glaucoma

      Objective To investigate the use of swept-source optical coherence tomography (OCT) for measuring the area and degree of peripheral anterior synechia (PAS) involvement in patients with angle-closure glaucoma. Design Cross-sectional study. Participants Twenty-three eyes with PAS (detected by indentation gonioscopy) from 20 patients with angle-closure glaucoma (20 eyes had primary angle-closure glaucoma and 3 eyes had angle-closure glaucoma secondary to chronic anterior uveitis [n = 2] and Axenfeld–Rieger syndrome [n = 1]). Methods The anterior chamber angles were evaluated with indentation gonioscopy and imaged by swept-source OCT (Casia OCT, Tomey, Nagoya, Japan) in room light and in the dark using the ...

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    13. Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography: Interpreting the RNFL maps in Healthy Myopic Eyes

      Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography: Interpreting the RNFL maps in Healthy Myopic Eyes

      Objective: To investigate the association between the distribution profile of the retinal nerve fiber layer (RNFL) bundles and myopia and its impact on interpretation of the RNFL map imaged by a spectral-domain optical coherence tomography (OCT). Methods: The RNFL of 189 myopic eyes from 103 normal healthy myopic participants was imaged by the Cirrus HD-OCT. The angle between the long axes of the superotemporal and inferotemporal RNFL bundles determined in the RNFL thickness map (the RNFL distribution angle) and the abnormal area in the RNFL thickness deviation map were measured. The associations between the RNFL distribution angle and the axial ...

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    14. Retinal Nerve Fiber Layer Imaging with Spectral-domain Optical Coherence Tomography: Patterns of Retinal Nerve Fiber Layer Progression

      Retinal Nerve Fiber Layer Imaging with Spectral-domain Optical Coherence Tomography: Patterns of Retinal Nerve Fiber Layer Progression

      Objective To examine the use of the retinal nerve fiber layer (RNFL) thickness map generated by a spectral-domain optical coherence tomography (OCT) to detect RNFL progression and identify the pattern of progressive changes of RNFL defects in glaucoma. Design Prospective, longitudinal study. Participants One hundred eighty-six eyes of 103 glaucoma patients. Methods Patients were followed at 4-month intervals for ≥36 months for RNFL imaging and visual field examination. Both eyes were imaged by the Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA) and had visual field testing at the same visits. We defined RNFL progression by Guided Progression Analysis (Carl ...

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    15. Optic Disc Imaging with Spectral-Domain Optical Coherence Tomography: Variability and Agreement Study with Heidelberg Retinal Tomograph

      Optic Disc Imaging with Spectral-Domain Optical Coherence Tomography: Variability and Agreement Study with Heidelberg Retinal Tomograph

      Objective To evaluate the agreement of optic disc measurements obtained with the Cirrus high-density optical coherence tomography (HD-OCT) and the Heidelberg retina tomograph (HRT) and compare the intervisit, test–retest variability between the instruments. Design Prospective, cross-sectional study. Participants Two hundred seven subjects (109 glaucoma and 98 normal subjects). Methods One eye from each individual was selected randomly for optic disc imaging by the Cirrus HD-OCT and the HRT. Areas of the optic disc and the cup, cup volume, vertical cup-to-disc ratio and cup-to-disc area ratio were compared between the instruments. The OCT measurements were corrected for ocular magnification using ...

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    16. Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography A Prospective Analysis of Age-Related Loss

      Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography A Prospective Analysis of Age-Related Loss

      Objective To investigate age-related changes of the retinal nerve fiber layer (RNFL) imaged by a spectral-domain optical coherence tomography (OCT). Design Prospective, cross-sectional, and longitudinal studies. Participants One hundred normal individuals were recruited for cross-sectional analysis, 35 of whom were randomly selected for longitudinal analysis. Methods The circumpapillary average and quadrant RNFL thicknesses were measured by the Cirrus HD-OCT. In the longitudinal study, participants were followed at 4-month intervals for a mean of 30 months (range, 24–41 months) for RNFL and visual field measurements. Cross-sectional RNFL data were analyzed with multiple linear regression models with adjustment of spherical error ...

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    17. Comparison of Retinal Nerve Fiber Layer Imaging by Spectral Domain Optical Coherence Tomography and Scanning Laser Ophthalmoscopy

      Comparison of Retinal Nerve Fiber Layer Imaging by Spectral Domain Optical Coherence Tomography and Scanning Laser Ophthalmoscopy
      Objective To compare the area and the angular width of localized retinal nerve fiber layer (RNFL) defects imaged by confocal scanning laser ophthalmoscopy (CSLO) and optical coherence tomography (OCT) and to evaluate their agreement. Design Cross-sectional study. Participants Fifty-one eyes of 41 glaucoma patients. Methods Sixty-one distinctive, localized RNFL defects (17 superior and 44 inferior RNFL defects) detected in RNFL photographs imaged by a CSLO were identified. These patients underwent RNFL imaging with a spectral-domain OCT. The RNFL thickness deviation maps (50×50 pixels) generated by the OCT revealed the locations of abnormal RNFL thicknesses with abnormal pixels denoted in ...
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    18. Anterior Chamber Angle Imaging with Swept-source Optical Coherence Tomography: An Investigation on Variability of Angle Measurement

      Anterior Chamber Angle Imaging with Swept-source Optical Coherence Tomography: An Investigation on Variability of Angle Measurement
      Purpose: To evaluate the reproducibility of anterior chamber angle measurements obtained by a swept-source optical coherence tomographer (OCT) and identify factors associated with its measurement variability. Methods: One eye from each individual was randomly selected from 30 normal subjects for anterior segment imaging with the Casia SS-1000 OCT (Tomey, Nogaya, Japan) in 3 separate visits within a week. The angle opening distance (AOD), the trabecular iris space area (TISA) and the trabecular-iris angle (TIA) at the superior (90°), nasal (0°), inferior (270°), and temporal (180°), angles were measured. The intra- and inter-observer reproducibility coefficient (RC) and intraclass correlation coefficient (ICC ...
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    19. Comparison with Scanning Laser Tomograph Reflectance Image

      Comparison with Scanning Laser Tomograph Reflectance Image
      jective To compare the area and the angular width of localized retinal nerve fiber layer (RNFL) defects imaged by confocal scanning laser ophthalmoscopy (CSLO) and optical coherence tomography (OCT) and to evaluate their agreement. Design Cross-sectional study. Participants Fifty-one eyes of 41 glaucoma patients. Methods Sixty-one distinctive, localized RNFL defects (17 superior and 44 inferior RNFL defects) detected in RNFL photographs imaged by a CSLO were identified. These patients underwent RNFL imaging with a spectral-domain OCT. The RNFL thickness deviation maps (50×50 pixels) generated by the OCT revealed the locations of abnormal RNFL thicknesses with abnormal pixels denoted in ...
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    20. Evaluation of Retinal Nerve Fiber Layer Progression in Glaucoma: A Comparison between Spectral-Domain and Time-Domain Optical Coherence Tomography

      Evaluation of Retinal Nerve Fiber Layer Progression in Glaucoma: A Comparison between Spectral-Domain and Time-Domain Optical Coherence Tomography
      Objective: To compare the performance of a spectral-domain optical coherence tomography (OCT) device and a time-domain OCT device to detect retinal nerve fiber layer (RNFL) progression in glaucoma patients.Design: Prospective study.Participants: One hundred twenty-eight eyes of 81 glaucoma patients.Methods: Patients were followed up at 4-month intervals for at least 24 months for RNFL imaging and visual field examination. Both eyes were imaged by the Cirrus HD-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) and the Stratus OCT (Carl Zeiss Meditec, Inc.) and underwent visual field testing at the same visit. Linear regression analyses between circumpapillary RNFL measurements (average ...
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    1-22 of 22
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    Evaluation of Retinal Nerve Fiber Layer Progression in Glaucoma: A Comparison between Spectral-Domain and Time-Domain Optical Coherence Tomography Comparison with Scanning Laser Tomograph Reflectance Image Anterior Chamber Angle Imaging with Swept-source Optical Coherence Tomography: An Investigation on Variability of Angle Measurement Comparison of Retinal Nerve Fiber Layer Imaging by Spectral Domain Optical Coherence Tomography and Scanning Laser Ophthalmoscopy Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography A Prospective Analysis of Age-Related Loss Optic Disc Imaging with Spectral-Domain Optical Coherence Tomography: Variability and Agreement Study with Heidelberg Retinal Tomograph Retinal Nerve Fiber Layer Imaging with Spectral-domain Optical Coherence Tomography: Patterns of Retinal Nerve Fiber Layer Progression Retinal Nerve Fiber Layer Imaging with Spectral-Domain Optical Coherence Tomography: Interpreting the RNFL maps in Healthy Myopic Eyes Anterior Chamber Angle Imaging with Swept-Source Optical Coherence Tomography: Measuring Peripheral Anterior Synechia in Glaucoma Corneal thickness and elevation measurements using swept source optical coherence tomography and slit scanning topography in normal and keratoconic eyes Trojan-Horse Diameter-Reducible Nanotheranostics for Macroscopic/Microscopic Imaging-Monitored Chemo-Antiangiogenic Therapy Thickness of retinal pigment epithelium–Bruch’s membrane complex in adult Chinese using optical coherence tomography