1. Fred K. Chen

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    1. Mentioned In 20 Articles

    2. Assessing the Use of Incorrectly Scaled Optical Coherence Tomography Angiography Images in Peer-Reviewed Studies

      Assessing the Use of Incorrectly Scaled Optical Coherence Tomography Angiography Images in Peer-Reviewed Studies
      Importance Individual differences in axial length affect the lateral magnification of in vivo retinal images and as a result can affect the accuracy of quantitative measurements made from these images. As measurements from optical coherence tomography angiography (OCTA) images are becoming increasingly used in the diagnosis and monitoring of a wide range of diseases, evaluating which studies use correctly scaled images is crucial to their interpretation. Objective To perform a ...
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    3. Clinical validation of the RTVue optical coherence tomography angiography image quality indicators

      Clinical validation of the RTVue optical coherence tomography angiography image quality indicators
      Importance All automated image quality indicators for en face optical coherence tomography angiography (OCTA) images require gold standard validation for determining optimal thresholds. Background A manual grading system (gold standard) for OCTA images was validated and compared to two automated image quality indicators: signal strength index (SSI) and scan quality index (SQI) generated by different software versions of the Optovue OCTA device. Design Retrospective cross‐sectional study. Participants 52 eyes ...
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    4. Automatic choroidal segmentation in OCT images using supervised deep learning methods

      Automatic choroidal segmentation in OCT images using supervised deep learning methods
      The analysis of the choroid in the eye is crucial for our understanding of a range of ocular diseases and physiological processes. Optical coherence tomography (OCT) imaging provides the ability to capture highly detailed cross-sectional images of the choroid yet only a very limited number of commercial OCT instruments provide methods for automatic segmentation of choroidal tissue. Manual annotation of the choroidal boundaries is often performed but this is impractical ...
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    5. Posterior Choroidal Stroma Reduces Accuracy of Automated Segmentation of Outer Choroidal Boundary in Swept Source Optical Coherence Tomography

      Posterior Choroidal Stroma Reduces Accuracy of Automated Segmentation of Outer Choroidal Boundary in Swept Source Optical Coherence Tomography
      Purpose : To determine the influence of choroidal boundary morphology on the accuracy of automated measurements of subfoveal choroidal thickness (SFCT) in swept source optical coherence tomography (SSOCT). Methods : A retrospective image analysis of foveal-centered horizontal line scans from normal and diseased eyes using the Topcon DRI OCT-1 Atlantis SSOCT was conducted. Subfoveal choroid-scleral junction (CSJ) and retina-choroidal junction (RCJ) morphologies were graded by two observers. Automated SFCT (A-SFCT) was compared ...
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    6. Axial Length Variation Impacts on Superficial Retinal Vessel Density and Foveal Avascular Zone Area Measurements Using Optical Coherence Tomography Angiography

      Axial Length Variation Impacts on Superficial Retinal Vessel Density and Foveal Avascular Zone Area Measurements Using Optical Coherence Tomography Angiography
      Purpose : To evaluate the impact of image magnification correction on superficial retinal vessel density (SRVD) and foveal avascular zone area (FAZA) measurements using optical coherence tomography angiography (OCTA). Methods : Participants with healthy retinas were recruited for ocular biometry, refraction, and RTVue XR Avanti OCTA imaging with the 3 3-mm protocol. The foveal and parafoveal SRVD and FAZA were quantified with custom software before and after correction for magnification error using ...
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    7. Enhanced Visualization of Subtle Outer Retinal Pathology by En Face Optical Coherence Tomography and Correlation with Multi-Modal Imaging

      Enhanced Visualization of Subtle Outer Retinal Pathology by En Face Optical Coherence Tomography and Correlation with Multi-Modal Imaging
      Purpose To present en face optical coherence tomography (OCT) images generated by graph-search theory algorithm-based custom software and examine correlation with other imaging modalities. Methods En face OCT images derived from high density OCT volumetric scans of 3 healthy subjects and 4 patients using a custom algorithm (graph-search theory) and commercial software (Heidelberg Eye Explorer software (Heidelberg Engineering)) were compared and correlated with near infrared reflectance, fundus autofluorescence, adaptive optics ...
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    8. Impact of retinal pigment epithelium pathology on spectral-domain optical coherence tomography-derived macular thickness and volume metrics and their intersession repeatability

      Impact of retinal pigment epithelium pathology on spectral-domain optical coherence tomography-derived macular thickness and volume metrics and their intersession repeatability
      Background To determine the impact of retinal pigment epithelium (RPE) pathology on intersession repeatability of retinal thickness and volume metrics derived from Spectralis spectral-domain optical coherence tomography (SD-OCT). Design Prospective cross-sectional single centre study. Participants 56 eyes of 56 subjects were divided into 3 groups: (A) normal RPE band (25 eyes), (B) RPE elevation: macular soft drusen (13 eyes) and (C) RPE attenuation: geographic atrophy or inherited retinal diseases (18 ...
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    9. Classification of image artefacts in optical coherence tomography angiography of the choroid in macular diseases

      Classification of image artefacts in optical coherence tomography angiography of the choroid in macular diseases
      Background To evaluate and classify image artefacts in optical coherence tomography (OCT) angiography (OCTA) of the choroid in a group of patients with macular diseases. Design Retrospective observational study. Participants 5 patients with age-related macular degeneration, 3 with central serous retinopathy, 1 with polypoidal choroidal vasculopathy and 1 with multiple evanescent white dot syndrome. Methods OCTA and OCT reflectivity (OCTR) maps were reviewed along with their fluorescein angiography and indocyanine ...
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    10. Repeatability of retinal thickness and volume metrics in neovascular age-related macular degeneration using the topcon 3DOCT-1000

      Repeatability of retinal thickness and volume metrics in neovascular age-related macular degeneration using the topcon 3DOCT-1000
      Optical coherence tomography (OCT) is a commonly used imaging modality that provides detailed cross-sectional retinal images. This has revolutionised management of neovascular age-related macular degeneration. The need for repeated anti-vascular endothelial growth factor injections has led to therapy being delivered using OCT-guided retreatment strategies with both qualitative OCT features of disease activity (e.g. macular fluid) and changes in retinal thickness as triggers for retreatment The purpose of this study ...
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    11. Novel optical coherence tomography classification of torpedo maculopathy

      Novel optical coherence tomography classification of torpedo maculopathy
      Background Torpedo maculopathy is a rare condition with a twofold clinical significance. Firstly, it is a differential of atypical congenital hypertrophy of the retinal pigment epithelium. Secondly, visual field loss has been reported. We demonstrate the spectrum of structural abnormality of torpedo maculopathy as seen on optical coherence tomography, and correlate this with age of presentation, fundus autofluorescence, retinal sensitivity loss and visual field abnormality. Design A retrospective, observational case ...
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    12. Zero delay switch technique in optical coherence tomography for duo enhanced vitreoretinal and choroidoscleral imaging in highly myopic eyes

      Zero delay switch technique in optical coherence tomography for duo enhanced vitreoretinal and choroidoscleral imaging in highly myopic eyes
      Posterior staphyloma is a concave depression of the posterior shell of the eye globe that is frequently observed in highly myopic eyes. As hallmark lesion, it is seen in 90% of patients with high myopia and increases in prevalence with age.1 Highly myopic eyes with posterior staphylomata have a higher probability of visual disturbances; the stretching of the posterior fundus results in various lesions such as chorioretinal atrophy, choroidal ...
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    13. Use of Spectral-Domain Optical Coherence Tomography to Differentiate Acquired Retinoschisis From Retinal Detachment in Difficult Cases

      Use of Spectral-Domain Optical Coherence Tomography to Differentiate Acquired Retinoschisis From Retinal Detachment in Difficult Cases
      Purpose: This study presents a series of 10 patients who posed a diagnostic challenge regarding the diagnosis of acquired retinoschisis (RS) or retinal detachment (RD), where spectral-domain optical coherence tomography (OCT) with the Spectralis HRA and OCT device (Heidelberg Engineering, Heidelberg, Germany) was able to help make a correct diagnosis. Methods: Ten patients (five with acquired RS and five with RD) were referred to a vitreoretinal clinic at Moorfields Eye ...
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    14. Topographic variation and interocular symmetry of macular choroidal thickness using enhanced depth imaging optical coherence tomography

      Topographic variation and interocular symmetry of macular choroidal thickness using enhanced depth imaging optical coherence tomography
      Purpose: To report and analyse factors influencing topographical and interocular variations of choroidal thickness (CT) in healthy adult population. Methods: 100 eyes of 50 healthy subjects underwent visual acuity and axial length measurements and optical coherence tomography with enhanced depth imaging using the Heidelberg Spectralis HRA+OCT. CT at the fovea, and 3 mm nasal, temporal, superior and inferior to the fovea were measured manually. Topographic variation, relative interocular differences ...
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    15. Repeatability of manual subfoveal choroidal thickness measurements in healthy subjects using the technique of enhanced depth imaging optical coherence tomography

      Repeatability of manual subfoveal choroidal thickness measurements in healthy subjects using the technique of enhanced depth imaging optical coherence tomography
      Purpose- The aim of this study was to investigate the repeatability of manual measurements of choroidal thickness in normal subjects imaged on spectral domain optical coherence tomography (OCT) using the enhanced depth imaging (EDI) technique. Methods- Fifty consecutive, healthy, young, adult volunteers with no known eye disease were enrolled prospectively. Two good quality, horizontal and vertical line scans through the fovea were obtained for each eye. Using the manual callipers ...
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    16. Intrasession repeatability of optical coherence tomography measures in active neovascular age-related macular degeneration

      Objectives: To determine the repeatability of Stratus optical coherence tomography fast macular thickness map analysis in patients with active neovascular age-related macular degeneration (nAMD).Methods: Consecutive pairs of scans from 112 eyes of 112 consecutive patients with active nAMD were analyzed. The Bland[ndash]Altman coefficient of repeatability (CR) was calculated for each retinal thickness or volume measure.Results: The CR for the central 1 mm macular subfield was 59 ...
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  2. About Fred K. Chen

    Fred K. Chen

    Fred K. Chen  is at the The University of Western Australia, Centre of Ophthalmology and Visual Science and the Royal Perth Hospital, Department of Ophthalmology, Perth, Western Australia