1. Articles from Jie Meng

    1-13 of 13
    1. Peripapillary Microvasculature Predicts the Incidence and Development of Diabetic Retinopathy: An SS-OCTA Study

      Peripapillary Microvasculature Predicts the Incidence and Development of Diabetic Retinopathy: An SS-OCTA Study

      Purpose : To examine the associations of peripapillary microvascular metrics with diabetic retinopathy (DR) incidence and development using swept-source optical coherence tomography angiography (SS-OCTA). Design : Prospective cohort study. Methods : 1033 eyes from 1033 type II diabetes mellitus (T2D) patients were included with 2-year follow-up. The peripapillary microvascular metrics at the superficial capillary plexus (SCP) were measured by SS-OCTA at the baseline, including peripapillary vascular density (pVD) and vascular length density (pVLD). The DR incidence and progression were evaluated with seven standard fields of stereoscopic color fundus photographs. The associations were tested with logistic regression models after adjusting established risk factors and ...

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    2. Segmentation Errors in the Measurement of Volumetric Parameters by Swept-Source Anterior Segment Optical Coherence Tomography

      Segmentation Errors in the Measurement of Volumetric Parameters by Swept-Source Anterior Segment Optical Coherence Tomography

      Purpose: To investigate the error rate of segmentation in the automatic measurement of anterior chamber volume (ACV) and iris volume (IV) by swept-source anterior segment optical coherence tomography (SS-ASOCT) in narrow-angle and wide-angle eyes. Methods: In this study, fifty eyes from 25 narrow-angle subjects and fifty eyes from 25 wide-angle subjects were enrolled. SS-ASOCT examinations were performed and each SS-ASOCT scan was reviewed, and segmentation errors in the automatic measurement of ACV and IV were classified and manually corrected. Error rates were compared between the narrow-angle and the wide-angle groups, and ACV and IV before and after manual correction were ...

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    3. Analysis of Iris volume using swept-source optical coherence tomography in patients with type 2 diabetes mellitus

      Analysis of Iris volume using swept-source optical coherence tomography in patients with type 2 diabetes mellitus

      Purpose: To evaluate iris volume before and after pupil dilation using swept-source anterior segment optical coherence tomography (SS-ASOCT) and investigate the associated factors of iris volume and iris volume change after pupil dilation in patients with type 2 diabetes mellitus (T2DM). Methods: A cross-sectional study was conducted in Zhongshan Ophthalmic Center among T2DM registered patients in the community of Guangzhou, China. Anterior chamber volume (ACV), iris volume, anterior chamber depth (ACD), angle opening distance at 500 μm (AOD 500) and pupil diameter were estimated using SS-ASOCT (CASIA; Tomey, Nagoya, Japan). Venous blood was taken for the measurement of glycosylated haemoglobin ...

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    4. Comparison of Macular Thickness Measurements Using Swept-Source and Spectral-Domain Optical Coherence Tomography in Healthy and Diabetic Subjects

      Comparison of Macular Thickness Measurements Using Swept-Source and Spectral-Domain Optical Coherence Tomography in Healthy and Diabetic Subjects

      Purpose : To establish normative data for macular thickness in Chinese aged 30 to 80 years using the swept-source optical coherence tomography (SS-OCT) device. Methods : The study included 290 normal eyes, 430 NDR eyes and 150 DR eyes of community residents aged 30 to 80 years in Guangzhou, China. Mean macular thicknesses in Early Treatment Diabetic Retinopathy Study (ETDRS) subfields, central point thicknesses (CPT), and macular volume was measured by SS-OCT (Triton DRI OCT, Topcon, Tokyo, Japan) and Spectral-Domain OCT (SD-OCT; Heidelberg Engineering, Heidelberg, Germany). We assessed agreement between SS-OCT and SD-OCT measurements by intraclass correlation coefficients (ICC) and Bland-Altman plots ...

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    5. Functional Monitoring after Trabeculectomy or XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography and Visual Field Indices—A Retrospective Comparative Cohort Study

      Functional Monitoring after Trabeculectomy or XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography and Visual Field Indices—A Retrospective Comparative Cohort Study

      The aim of this study was to compare the efficacy of trabeculectomy (TE), single XEN microstent implantation (solo XEN) or combined XEN implantation and cataract surgery (combined XEN) in primary open-angle glaucoma cases, naïve to prior surgical treatment, using a monocentric retrospective comparative cohort study. Intraocular pressure (IOP) and the number of IOP-lowering drugs (Meds) were monitored during the first 24 months after surgery. Further disease progression was monitored using peripapillary retinal nerve fiber layer (RNFL) thickness examinations using spectral domain optical coherence tomography (OCT) as well as visual acuity (VA) and visual field (VF) tests. In the TE ...

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    6. Association of renal function with retinal vessel density in patients with type 2 diabetes by using swept-source optical coherence tomographic angiography

      Association of renal function with retinal vessel density in patients with type 2 diabetes by using swept-source optical coherence tomographic angiography

      Aims To investigate the relationship between retinal vessel density and renal function in patients with diabetes mellitus (DM) using non-invasive optical coherence tomographic angiography (OCTA). Methods This prospective cross-sectional study recruited ocular-treatment-naïve patients with DM registered in the community of Guangzhou, China. The retinal vessel density of the superficial capillary plexus in the macula was obtained by using swept-source OCTA imaging. The Xiangya equation was used to calculate the estimated glomerular filtrate rate (eGFR). Participants were divided into the following groups by eGFR: no chronic kidney disease (non-CKD), mild CKD and moderate-to-severe CKD (MS-CKD). Results A total of 874 ...

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    7. Monitoring of drug and stimulation induced cerebral blood flow velocity changes in rat sensory cortex using spectral domain Doppler optical coherence tomography

      Monitoring of drug and stimulation induced cerebral blood flow velocity changes in rat sensory cortex using spectral domain Doppler optical coherence tomography

      Doppler optical coherence tomography (DOCT) provides a novel method to measure blood flow velocity in vessels with diameter at micrometer scale. In this study, a developed spectral domain DOCT system is applied to monitor cerebral blood flow velocity changes in a rat. An animal model with a cranial window is used, and by application of a drug, light, and electric stimulations, changes in blood flow velocity of the pial artery in sensory cortex are measured in real time. The results show significant differences in blood flow velocity before and after drug administration or light and electric stimulations, demonstrating the feasibility ...

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    8. Deconvolution with fall-off compensated axial point spread function in spectral domain optical coherence tomography

      Deconvolution with fall-off compensated axial point spread function in spectral domain optical coherence tomography

      A deconvolution method for image enhancement suitable for spectral domain optical coherence tomography (SD-OCT) is proposed. The method includes Wiener filtering for spectral deconvolution and successive homomorphic filtering for spatial deconvolution, aiming to minimize blurring effect of axial point spread function (PSF) and its depth dependence. Tunable factor in Wiener filtering is optimized for tradeoff between compensation ratio and signal-to-noise ratio (SNR). In vivo OCT imaging of a fresh shrimp is done and image reconstructions are performed. Comparing results demonstrates the proposed method suppresses the coherent noises in OCT image while compensating sensitivity fall-off with increased averaged SNR and recovers ...

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    9. Transit-time analysis based on delay-encoded beam shape for velocity vector quantification by spectral-domain Doppler optical coherence tomography

      Transit-time analysis based on delay-encoded beam shape for velocity vector quantification by spectral-domain Doppler optical coherence tomography

      We propose a transit-time based method to ascertain the azimuth angle of a velocity vector by spectral-domain Doppler optical coherence tomography (DOCT), so that three-dimensional (3-D) velocity vector can be quantified. A custom-designed slit plate with predetermined slit orientation is placed into the sample beam to create three delay-encoded sub-beams of different beam shape for sample probing. Based on the transit-time analysis for Doppler bandwidth, the azimuth angle within 90° range is evaluated by exploitation of the complex signals corresponding to three path length delays. 3-D velocity vector is quantified through further estimating of Doppler angle and flow velocity by ...

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    10. Development of a high speed spectral domain optical coherence tomography system at 835 nm

      We develop a high speed multi-functional spectral domain (SD-OCT) system, using a broadband light source centered at 835nm and a custom-built spectrometer with a spectral resolution of 0.0674nm. After precise spectral calibration of the spectrometer, non-uniform discrete Fourier transform (NDFT) of the acquired spectral data is adopted for image reconstruction. In vivo imaging of human finger from volunteer at A-scan rate of 29 kHz with different reconstruction methods reveal that with the NDFT method, improved sensitivity fall-off especially at large depth is achieved in contrast to the conventional discrete Fourier transform (DFT) with interpolation method. And the phase information ...

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    11. Sinusoidal B-M method based spectral domain optical coherence tomography for the elimination of complex-conjugate artifact

      Sinusoidal B-M method based spectral domain optical coherence tomography for the elimination of complex-conjugate artifact

      A high speed spectral domain optical coherence tomography based on the spatial sinusoidal phase modulation for the elimination of complex-conjugate artifact is presented, where sinusoidal phase modulation of reference arm (M scan) and transverse scanning of sample arm (B scan) are performed simultaneously (sinusoidal B-M method). Herein, the linear phase modulation of the reference arm in conventional linear B-M method is modified to sinusoidal phase modulation. The proposed sinusoidal B-M method relaxes the requirements on the phase-shifting mechanical system and avoids sensitivity fall-off along the transverse direction in contrast to the linear B-M method. A criterion for the relation between ...

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    12. Development of a non-uniform discrete Fourier transform based high speed spectral domain optical coherence tomography system

      Development of a non-uniform discrete Fourier transform based high speed spectral domain optical coherence tomography system

      We develop a high speed spectral domain optical coherence tomography (SD-OCT) system based on a custom-built spectrometer and non-uniform discrete Fourier transform (NDFT) to realize minimized depth dependent sensitivity fall-off. After precise spectral calibration of the spectrometer, NDFT of the acquired spectral data is adopted for image reconstruction. The spectrometer is able to measure a wavelength range of about 138nm with a spectral resolution of 0.0674nm at central wavelength of 835nm, corresponding to an axial imaging range of 2.56mm in air. Zemax simulations and sensitivity fall-off measurements under two alignment states of the spectrometer are given. Both theoretical ...

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    13. Common path endoscopic optical coherence tomography with outside path length compensation

      Endoscopic optical coherence tomography (OCT) allowing high-resolution imaging of internal tissue is attractive for medical imaging. Fibre, fibre bundle or GRIN lens rod acting as endoscopic probe is placed in the sample arm of a Michelson interferometer in current endoscopic OCT systems, this arrangement has to be carefully configured to avoid dispersion and polarization fading. In this study, a common path OCT system with outside path length compensation is presented. The system based on Fizeau configuration requires a Michelson interferometer to compensate the optical path difference between the reference and signal light in the Fizeau sensing interferometer. Experiments of path ...

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    1-13 of 13
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  2. Topics in the News

    1. (7 articles) Zhejiang University
    2. (5 articles) Sun Yat-Sen University
    3. (2 articles) Sun Yat-Sen University
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    5. (1 articles) The Chinese University of Hong Kong
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    Development of a non-uniform discrete Fourier transform based high speed spectral domain optical coherence tomography system Sinusoidal B-M method based spectral domain optical coherence tomography for the elimination of complex-conjugate artifact Transit-time analysis based on delay-encoded beam shape for velocity vector quantification by spectral-domain Doppler optical coherence tomography Deconvolution with fall-off compensated axial point spread function in spectral domain optical coherence tomography Monitoring of drug and stimulation induced cerebral blood flow velocity changes in rat sensory cortex using spectral domain Doppler optical coherence tomography Association of renal function with retinal vessel density in patients with type 2 diabetes by using swept-source optical coherence tomographic angiography Comparison of Macular Thickness Measurements Using Swept-Source and Spectral-Domain Optical Coherence Tomography in Healthy and Diabetic Subjects Analysis of Iris volume using swept-source optical coherence tomography in patients with type 2 diabetes mellitus Prognostic Features of Preoperative Optical Coherence Tomography in Retinal Detachments: A systematic review and meta-analysis Automatic assessment of calcified plaque and nodule by optical coherence tomography adopting deep learning model Coronary plaque characterization assessed by delayed enhancement dual-layer spectral CT angiography and optical coherence tomography Use of multimodal dataset in AI for detecting glaucoma based on fundus photographs assessed with OCT: focus group study on high prevalence of myopia