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Detecting early changes in choroidal vascularity and thickness using optical coherence tomography in patients with corneal crosslinking for keratoconus
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作者 Selim Doganay Mehmet Omer Kiristioglu +1 位作者 Derya Doganay Elif Kacmaz 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第7期1267-1272,共6页
AIM:To investigate changes in choroidal thickness and vascularity in keratoconus patients treated with corneal crosslinking.METHODS:This study evaluated 28 eyes of 22 patients with keratoconus who underwent corneal cr... AIM:To investigate changes in choroidal thickness and vascularity in keratoconus patients treated with corneal crosslinking.METHODS:This study evaluated 28 eyes of 22 patients with keratoconus who underwent corneal crosslinking.The choroidal thicknesses were evaluated on enhanced depth imaging optical coherence tomography at the preoperative and postoperative 3d,1,and 3mo.Choroidal thickness in the four cardinal quadrants and the fovea were evaluated.The choroidal vascularity index was also calculated.RESULTS:There was no significant difference in central choroidal thickness between the preoperative and postoperative 3d,1mo(P>0.05).There was a significant increase in the 3mo(P=0.034)and a significant decrease in the horizontal choroidal vascularity index on the postoperative 3d(P=0.014),there was no statistically significant change in vertical axes and other visits in horizontal sections(P>0.05).CONCLUSION:This study sheds light on choroidal changes in postoperative corneal crosslinking for keratoconus.While it suggests the procedure’s relative safety for submacular choroid,more extensive research is necessary to confirm these findings and their clinical significance. 展开更多
关键词 KERATOCONUS corneal crosslinking choroidal vascularity index enhanced depth imaging optical coherence tomography
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Optical coherence tomography enhanced depth imaging of chorioretinal folds in patients with orbital tumors
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作者 Zhi-Yu Peng Lu Gan +4 位作者 Kang Xue Akrit Sodhi Xiao-Feng Ye Hui Ren Jiang Qian 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第2期233-237,共5页
AIM:To characterize spectral-domain optical coherence tomography(SD-OCT)features of chorioretinal folds in orbital mass imaged using enhanced depth imaging(EDI).METHODS:Prospective observational case-control study was... AIM:To characterize spectral-domain optical coherence tomography(SD-OCT)features of chorioretinal folds in orbital mass imaged using enhanced depth imaging(EDI).METHODS:Prospective observational case-control study was conducted in 20 eyes of 20 patients,the uninvolved eye served as a control.All the patients underwent clinical fundus photography,computed tomography,EDI SDOCT imaging before and after surgery.Two patients with cavernous hemangiomas underwent intratumoral injection of bleomycin A5;the remaining patients underwent tumor excision.Patients were followed 1 to 14mo following surgery(average follow up,5.8mo).RESULTS:Visual acuity prior to surgery ranged from 20/20 to 20/200.Following surgery,5 patients’visual acuity remained unchanged while the remaining 15 patients had a mean letter improvement of 10(range 4 to 26 letters).Photoreceptor inner/outer segment defects were found in 10 of 15 patients prior to surgery.Following surgical excision,photoreceptor inner/outer segment defects fully resolved in 8 of these 10 patients.CONCLUSION:Persistence of photoreceptor inner/outer segment defects caused by compression of the globe by an orbital mass can be associated with reduced visual prognosis.Our findings suggest that photoreceptor inner/outer segment defects on EDI SD-OCT could be an indicator for immediate surgical excision of an orbital mass causing choroidal compression. 展开更多
关键词 chorioretinal folds orbital mass enhanced depth imaging optical coherence tomography choroidal thickness inner/outer segment defects
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Assessment of posterior vitreous detachment on enhanced high density line optical coherence tomography 被引量:2
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作者 Yu Cheol Kim Mariana Harasawa +1 位作者 Frank S Siringo Hugo Quiroz-Mercado 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第1期165-167,共3页
The state of the vitreo-retinal interface affects various retinal diseases, and the presence or absence of a posterior vitreous detachment (PVD) is one of the most important factors. As such, various studies studyin... The state of the vitreo-retinal interface affects various retinal diseases, and the presence or absence of a posterior vitreous detachment (PVD) is one of the most important factors. As such, various studies studying PVD in relation to retinal disease have been performed. 展开更多
关键词 LINE PPVP PVD Assessment of posterior vitreous detachment on enhanced high density line optical coherence tomography FIGURE HIGH
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Optical coherence tomography with or without enhanced depth imaging for peripapillary retinal nerve fiber layer and choroidal thickness 被引量:1
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作者 Meng-Ai Wu Wei-Xin Xu +1 位作者 Zhe Lyu Li-Jun Shen 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第10期1539-1544,共6页
AIM:To assess peripapillary retinal nerve fiber layer(RNFL)and choroidal thickness obtained with enhanced depth imaging(EDI)mode compared with those obtained without EDI mode using Heidelberg Spectralis optical c... AIM:To assess peripapillary retinal nerve fiber layer(RNFL)and choroidal thickness obtained with enhanced depth imaging(EDI)mode compared with those obtained without EDI mode using Heidelberg Spectralis optical coherence tomography(OCT).METHODS:Fifty eyes of 25 normal healthy subjects and32 eyes of 20 patients with different eye diseases were included in the study.All subjects underwent 3.4 mm diameter peripapillary circular OCT scan centered on the optic disc using both the conventional and the EDI OCT protocols.The visualization of RNFL and choroidoscleral junction was assessed using an ordinal scoring scale.The paired t-test,intraclass correlation coefficient(ICC),95%limits of agreement(LoA),and Bland and Altman plots were used to test the agreement of measurements.RESULTS:The visibility score of RNFL obtained with and without EDI was of no significant difference(P=0.532),the visualization of choroidoscleral junction was better using EDI protocol than conventional protocol(P〈0.001).Peripapillary RNFL thickness obtained with EDI was slightly thicker than that obtained without EDI(103.25±9.42μm vs 101.87±8.78μm,P=0.010).The ICC of the two protocols was excellent with the value of 0.867 to 0.924,the 95%LoA of global RNFL thickness was between-10.0 to 7.4μm.Peripapillary choroidal thickness obtained with EDI was slightly thinner than that obtained without EDI(147.23±51.04μm vs 150.90±51.84μm,P〈0.001).The ICC was also excellent with the value of 0.960 to 0.987,the 95%LoA of global choroidal thickness was between-12.5 to 19.8μm.CONCLUSION:Peripapillary circular OCT scan with or without EDI mode shows comparable results in the measurement of peripapillary RNFL and choroidal thickness. 展开更多
关键词 enhanced depth imaging optical coherence tomography choroidal thickness peripapillary retinal nerve fiber layer
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Peripapillary choroidal thickness in Chinese children using enhanced depth imaging optical coherence tomography
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作者 Xi-Shi Wu Li-Jun Shen +1 位作者 Ru-Ru Chen Zhe Lyu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第10期1451-1456,共6页
AIM:To evaluate the peripapillary choroidal thickness(PPCT) in Chinese children,and to analyze the influencing factors.METHODS: PPCT was measured with enhanced depth imaging optical coherence tomography(EDI-OCT)... AIM:To evaluate the peripapillary choroidal thickness(PPCT) in Chinese children,and to analyze the influencing factors.METHODS: PPCT was measured with enhanced depth imaging optical coherence tomography(EDI-OCT) in 70children(53 myopes and 17 non-myopes) aged 7 to 18 y,with spherical equivalent refractive errors between 0.50and-5.87 diopters(D).Peripapillary choroidal imaging was performed using circular scans of a diameter of 3.4 mm around the optic disc.PPCT was measured by EDI-OCT in six sectors: nasal(N),superonasal(SN),superotemporal(ST),temporal(T),inferotemporal(IT)and inferonasal(IN),as well as global RNFL thickness(G).RESULTS: The mean global PPCT was 165.49±33.76 μm.The temporal,inferonasal,inferotemporal PPCT were significantly thinner than the nasal,superonasal,superotemporal segments PPCT were significantly thinner in the myopic group at temporal,superotemporal and inferotemporal segments.The axial length was significantly associated with the average global(β=-0.419,P =0.014),superonasal(β=-2.009,P=0.049) and inferonasal(β=-2.000,P=0.049) PPCT.The other factors(gender,age,SE) were not significantly associated with PPCT.CONCLUSION: PPCT was thinner in the myopic group at temporal,superotemporal and inferotemporal segments.The axial length was found to be negatively correlated to PPCT.We need more further studies about the relationship between PPCT and myopia. 展开更多
关键词 peripapillary choroidal thickness enhanced depth imaging optical coherence tomography Chinese children
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Coherent Features of Resonance-Mediated Two-Photon Absorption Enhancement by Varying the Energy Level Structure,Laser Spectrum Bandwidth and Central Frequency
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作者 程文静 梁果 +3 位作者 吴萍 贾天卿 孙真荣 张诗按 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第8期41-45,共5页
The femtosecond pulse shaping technique has been shown to be an effective method to control the multi-photon absorption by the light–matter interaction. Previous studies mainly focused on the quantum coherent control... The femtosecond pulse shaping technique has been shown to be an effective method to control the multi-photon absorption by the light–matter interaction. Previous studies mainly focused on the quantum coherent control of the multi-photon absorption by the phase, amplitude and polarization modulation, but the coherent features of the multi-photon absorption depending on the energy level structure, the laser spectrum bandwidth and laser central frequency still lack in-depth systematic research. In this work, we further explore the coherent features of the resonance-mediated two-photon absorption in a rubidium atom by varying the energy level structure, spectrum bandwidth and central frequency of the femtosecond laser field. The theoretical results show that the change of the intermediate state detuning can effectively influence the enhancement of the near-resonant part, which further affects the transform-limited (TL)-normalized final state population maximum. Moreover, as the laser spectrum bandwidth increases, the TL-normalized final state population maximum can be effectively enhanced due to the increase of the enhancement in the near-resonant part, but the TL-normalized final state population maximum is constant by varying the laser central frequency. These studies can provide a clear physical picture for understanding the coherent features of the resonance-mediated two-photon absorption, and can also provide a theoretical guidance for the future applications. 展开更多
关键词 TL Coherent Features of Resonance-Mediated Two-Photon Absorption enhancement by Varying the Energy Level Structure Laser Spectrum Bandwidth and Central Frequency
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Surface plasmon polaritons frequency-blue shift in low confinement factor excitation region
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作者 Ling-Xi Hu Zhi-Qiang He +1 位作者 Min Hu Sheng-Gang Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第8期345-350,共6页
Surface plasmon polaritons'(SPPs')frequency blue shift is observed in finite-difference time-domain(FDTD)simulation of parallel electron excitation Au bulk structure.Comparing with cold dispersion of SPPs,an o... Surface plasmon polaritons'(SPPs')frequency blue shift is observed in finite-difference time-domain(FDTD)simulation of parallel electron excitation Au bulk structure.Comparing with cold dispersion of SPPs,an obvious frequency blue shift is obtained in low confinement region excitation simulation results.Then,according to SPPs'transverse attenuation characteristics,the excited frequency mode instead of cold dispersion corresponding frequency mode matches it.Thence,this excited mode is confirmed to be SPPs'mode.As is well known the lower the frequency,the smaller the confinement factor is and the lower the excitation efficiency,the wider the bandwidth of excited SPPs is.And considering the attenuation in whole structure,the excited surface field contains attenuation signal.In a low confinement factor region,the higher the SPPs'frequency,the higher the excitation efficiency is,while broadband frequency information obtained in attenuation signal provides high frequency information in stimulation signal.Thence,in the beam-wave interaction,as the signal oscillation time increases,the frequency of the oscillation field gradually increases.Thus,compared with cold dispersion,the frequency of excited SPP is blueshifted This hypothesis is verified by monitoring the time domain signal of excited field in low and high confinement factor regions and comparing them.Then,this frequency-blue shift is confirmed to have commonality of SPPs,which is independent of SPPs'material and structure.Finally,this frequency-blue shift is confirmed in an attenuated total reflection(ATR)experiment.Owing to frequency dependence of most of SPPs'devices,such as coherent enhancement radiation and enhancement transmission devices,the frequency-blue shift presented here is of great influence in the SPPs applications. 展开更多
关键词 surface plasmon polaritons(SPPs) frequency-blue shift surface plasmon resonance(SPR) coherent enhancement radiation
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High enhancement factor of Au nano triangular prism structure for surface enhanced coherent anti-Stokes Raman scattering
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作者 Zuyin Zhang Guofeng Song 《Journal of Semiconductors》 EI CAS CSCD 2017年第2期1-4,共4页
Coherent anti-Stokes Raman scattering spectroscopy(CARS) is a well-known detecting tool in biosensing and nonlinear spectroscopy. It can provide a non-invasive alternative without the need for exogenous labels,while... Coherent anti-Stokes Raman scattering spectroscopy(CARS) is a well-known detecting tool in biosensing and nonlinear spectroscopy. It can provide a non-invasive alternative without the need for exogenous labels,while the enhancement factor for surface plasmon resonances(SPR) are extensively used to increase the local field close to the oscillators and which can obtain high enhancement. In this work, we investigate the enhancement factor of our structure for surface-enhanced coherent anti-Stokes Raman scattering. The absorption spectrum of the structure has been studied, a wide range of absorption has been realized. The enhancement can be as high as 10^(16) over standard CARS. Our design is very useful for improving the enhancement factor of surface-enhanced coherent anti-Stokes Raman scattering. 展开更多
关键词 coherent anti-stokes Raman scattering(CARS) enhancement factor localized surface plasmon
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Choroidal vascularity index in thyroidassociated ophthalmopathy:a crosssectional study
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作者 Pasquale Loiudice Marco Pellegrini +6 位作者 Michele Marino Barbara Mazzi Ilaria Ionni Giuseppe Covello Michele Figus Marco Nardi Giamberto Casini 《Eye and Vision》 SCIE CSCD 2023年第4期21-28,共8页
Background:Hemodynamic changes have been observed in patients with Graves'disease.The aim of our study was to evaluate choroidal vascular change using the choroidal vascularity index(CVi)in patients with thyroid-a... Background:Hemodynamic changes have been observed in patients with Graves'disease.The aim of our study was to evaluate choroidal vascular change using the choroidal vascularity index(CVi)in patients with thyroid-associated ophthalmopathy(TAO).Methods:In this cross-sectional observational study,40 patients affected by TAO were recruited.Forty healthy individuals,matched for age and sex,served as controls.Foveal enhanced-depth imaging optical coherence tomography scans were obtained from all participants.Images were binarized using the ImageJ software and luminal area(LA)and total choroidal area(TCA)were measured.CVI was calculated as the proportion of LA to TCA.The relation between CVI or subfoveal choroidal thickness(SFCT)and clinical activity score,exophthalmometric value,diplopia status,gender,and age was evaluated.Results:CVI was significantly higher in patients with TAO(P=0.004).No significant difference was observed in SFCT(P=0.200)and TCA(P=0.153)comparing TAO patients and healthy controls.LA was significantly higher in TAO group(P=0.045).On multiple regression analysis,CVI was associated with TCA(P=0.043).No association Was found between SFCT or CVI and TCA,clinical activity score,exophthalmometric value,Inami value,diplopia status,genderorage(P>0.05).Conclusions:This is the first study that has demonstrated an increase in CVI in eyes with TAO compared with healthy controls and has assessed its association with clinical features. 展开更多
关键词 Choroidal vascularity index Choroidal vasculature Enhanced depth optical coherence tomography Image binarization Luminal area Subfoveal choroidal thickness Thyroid-associate ophthalmopathy
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Choroidal vascularity index in thyroidassociated ophthalmopathy:a crosssectional study 被引量:1
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作者 Pasquale Loiudice Marco Pellegrini +6 位作者 Michele Marinò Barbara Mazzi Ilaria Ionni Giuseppe Covello Michele Figus Marco Nardi Giamberto Casini 《Eye and Vision》 SCIE CSCD 2021年第1期175-182,共8页
Background:Hemodynamic changes have been observed in patients with Graves’disease.The aim of our study was to evaluate choroidal vascular change using the choroidal vascularity index(CVI)in patients with thyroidassoc... Background:Hemodynamic changes have been observed in patients with Graves’disease.The aim of our study was to evaluate choroidal vascular change using the choroidal vascularity index(CVI)in patients with thyroidassociated ophthalmopathy(TAO).Methods:In this cross-sectional observational study,40 patients affected by TAO were recruited.Forty healthy individuals,matched for age and sex,served as controls.Foveal enhanced-depth imaging optical coherence tomography scans were obtained from all participants.Images were binarized using the ImageJ software and luminal area(LA)and total choroidal area(TCA)were measured.CVI was calculated as the proportion of LA to TCA.The relation between CVI or subfoveal choroidal thickness(SFCT)and clinical activity score,exophthalmometric value,diplopia status,gender,and age was evaluated.Results:CVI was significantly higher in patients with TAO(P=0.004).No significant difference was observed in SFCT(P=0.200)and TCA(P=0.153)comparing TAO patients and healthy controls.LA was significantly higher in TAO group(P=0.045).On multiple regression analysis,CVI was associated with TCA(P=0.043).No association was found between SFCT or CVI and TCA,clinical activity score,exophthalmometric value,Inami value,diplopia status,gender or age(P>0.05).Conclusions:This is the first study that has demonstrated an increase in CVI in eyes with TAO compared with healthy controls and has assessed its association with clinical features. 展开更多
关键词 Choroidal vascularity index Choroidal vasculature Enhanced depth optical coherence tomography Image binarization Luminal area Subfoveal choroidal thickness Thyroid-associate ophthalmopathy
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An improvement of adaptive line enhancer by means of coherent accumulation algorithm
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作者 HOU Baochun HUI Junying CAI Ping(Underwater Acoustics Institute of HSEI) 《Chinese Journal of Acoustics》 1990年第4期358-364,共7页
It is well known that the adaptive line enhancer (ALE) is effective detector of CW signal with unknown frequency in the background of white noise. The system processing gain of ALE, when the LMS algorithm is used, how... It is well known that the adaptive line enhancer (ALE) is effective detector of CW signal with unknown frequency in the background of white noise. The system processing gain of ALE, when the LMS algorithm is used, however, is not satisfactory because of the presence of iterative noise and weight noise. In this paper, the coherent accumulation algorithm of ALE, called as ALECA, is suggested. It is shown that the adaptive filter employing this new algorithm possesses the ARMA structure. The experimental results also show that the processing gain of ALECA is about 14dB higher than that of conventional ALE. 展开更多
关键词 ALE LINE An improvement of adaptive line enhancer by means of coherent accumulation algorithm
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