Background:A variety of experimental animal models are used in basic ophthalmological research to elucidate physiological mechanisms of vision and disease pathogenesis.The choice of animal model is based on the measur...Background:A variety of experimental animal models are used in basic ophthalmological research to elucidate physiological mechanisms of vision and disease pathogenesis.The choice of animal model is based on the measurability of specific parameters or structures,the applicability of clinical measurement technologies,and the similarity to human eye function.Studies of eye pathology usually compare optical parameters between a healthy and altered state,so accurate baseline assessments are critical,but few reports have comprehensively examined the normal anatomical structures and physiological functions in these models.Methods:Three cynomolgus monkeys,six New Zealand rabbits,ten Sprague Dawley(SD)rats,and BALB/c mice were examined by fundus photography(FP),fundus fluorescein angiography(FFA),and optical coherence tomography(OCT).Results:Most retinal structures of cynomolgus monkey were anatomically similar to the corresponding human structures as revealed by FP,FFA,and OCT.New Zealand rabbits have large eyeballs,but they have large optic disc and myelinated retinal nerve fibers in their retinas,and the growth pattern of retinal vessels were also different to the human retinas.Unlike monkeys and rabbits,the retinal vessels of SD rats and BALB/c mice were widely distributed and clear.The OCT performance of them were similar with human beings except the macular.Conclusions:Monkey is a good model to study changes in retinal structure associated with fundus disease,rabbits are not suitable for studies on retinal vessel diseases and optic nerve diseases,and rats and mice are good models for retinal vascular diseases.These measures will help guide the choice of model and measurement technology and reduce the number of experimental animals required.展开更多
The eye is an immune-privileged and sensory organ in humans and animals.Anatomical,physiological,and pathobiological features share significant similarities across divergent species(1).Each compartment of the eye has ...The eye is an immune-privileged and sensory organ in humans and animals.Anatomical,physiological,and pathobiological features share significant similarities across divergent species(1).Each compartment of the eye has a unique structure and function.The anterior and posterior compartments of the eye contain endothelium(cornea),epithelium(cornea,ciliary body,iris),muscle(ciliary body),vitreous and neuronal(retina)tissues,which make the eye suitable to evaluate efficacy and safety of tissue specific drugs(2).展开更多
Optical coherence tomography(OCT)is a technology that is widely used to assess structural abnormalities in the retina for a variety of pediatric conditions.The introduction of this instrument has allowed for widesprea...Optical coherence tomography(OCT)is a technology that is widely used to assess structural abnormalities in the retina for a variety of pediatric conditions.The introduction of this instrument has allowed for widespread access to minimally invasive standardized,reproducible quantified structural assessments of the optic nerve and retina.This has had important implications in pediatric optic neuropathies,populations in whom monitoring of disease activity is essential to make treatment decisions.OCT has had particular relevance for inflammatory optic neuropathies,as onset of an inflammatory optic neuropathy may herald the onset of a chronic inflammatory disorder of the central nervous system(CNS)such as multiple sclerosis,neuromyelitis optica spectrum disorder(aquaporin 4 antibody positive),and myelin oligodendrocyte glycoprotein(MOG)associated disorders.This paper will focus on the application of OCT technology to this group of disorders in pediatrics.After reviewing pediatric-specific anatomic and practical issues pertinent to OCT,we will review knowledge related to the use of OCT in inflammatory pediatric optic neuropathies,with a focus on structural outcomes and their correlation with functional outcome metrics.展开更多
Photodynamic therapy(PDT)is a promising tool for least-invasive alternative methods for the treatment of brain tumors.The newly discovered PDT-induced opening of the blood–brain barrier(BBB)permeability open novel st...Photodynamic therapy(PDT)is a promising tool for least-invasive alternative methods for the treatment of brain tumors.The newly discovered PDT-induced opening of the blood–brain barrier(BBB)permeability open novel strategies for drug-brain delivery during post-surgical treatment of glioblastoma GBM.Here we discuss mechanisms of PDT-mediated opening of the BBB and age differences in PDT-related increase in BBB permeability,including with formation of brain edema.The meningeal lymphatic system plays a crucial role in the mechanism of brain drainage and clearance from metabolites and toxic molecules.We discuss that noninvasive photonic stimulation of°uid clearance via meningeal lymphatic vessels,and application of optical coherence tomography(OCT)for bed-side monitoring of meningeal lymphatic drainage has the promising perspective to be widely applied in both experimental and clinical studies of PDT and improving guidelines of PDT of brain tumors.展开更多
Optical coherence tomography(OCT)and Raman spectroscopy(RS)can be complementary biological tissue optical analysis methods.To study the internal structure and tissue compositions of biological samples,an OCT-RS system...Optical coherence tomography(OCT)and Raman spectroscopy(RS)can be complementary biological tissue optical analysis methods.To study the internal structure and tissue compositions of biological samples,an OCT-RS system was built to carry out OCT section imaging and RS analysis in common.Neocaridina denticulate sinensis were collected regularly for morphological observation by OCT imaging and biochemical investigation based on the Raman spectra.The internal structure of the N.denticulate sinensis was imaged by OCT,and the morphology of the tissues and the position in the body were distinguished according to the gray scale changes.The imaging depth along the vertical direction of Z-axis in N.denticulate sinensis is about 1.60 mm.RS detection was selectively performed based on the OCT images.The main Raman peaks of the rostrum,the cephalothorax,the abdominal segment,and the telson section are at 1006,1156,1447,1491 and 1515 cm-1,which are identified as proteins and amino acids.The presence of 1497 cm-1 at the cephalothorax is different from other parts,probably due to the presence of organs such as ovary,whose compositions are different from those of other tissues.The combination of optical coherence tomography and Raman spectroscopy can provide information about morphological and biochemical features of tissues,and has potential applications in biomedical detection and imaging.展开更多
Optical coherence tomography (OCT) is a relatively new imaging technology which can produce high resolution images of three-dimensional structures. OCT has been mainly used for medical applications such as for ophthal...Optical coherence tomography (OCT) is a relatively new imaging technology which can produce high resolution images of three-dimensional structures. OCT has been mainly used for medical applications such as for ophthalmology and dermatology. In this study we demonstrate its capability in providing much more reliable biometry identification of fingerprints than conventional methods. We prove that OCT can serve secure control of genuine fingerprints as it can detect if extra layers are placed above the finger. This can prevent with a high probability, intruders to a secure area trying to foul standard systems based on imaging the finger surface. En-Face OCT method is employed and recommended for its capability of providing not only the axial succession of layers in depth, but the en-face image that allows the traditional pattern identification. Another reason for using such OCT technology is that it is compatible with dynamic focus and therefore can provide enhanced transversal resolution and sensitivity. Two En-Face OCT systems are used to evaluate the need for high resolution and conclusions are drawn in terms of the most potential commercial route to ex- ploitation.展开更多
Doppler Optical Coherence Tomography(DOCT)is a noninvasive optical diagnostic technique,which is well suited for the quantitative mapping of microflow velocity profiles and the analysis of flow-vessel interactions.The...Doppler Optical Coherence Tomography(DOCT)is a noninvasive optical diagnostic technique,which is well suited for the quantitative mapping of microflow velocity profiles and the analysis of flow-vessel interactions.The noninvasive imaging and quantitative analysis of blood flow in the complex-structured vascular bed is required in many biomedical applications,including those where the determination of mechanical properties of vessels or the knowledge of the mechanic interactions between the flow and the housing medium plays a key role.The change of microvessel wall elasticity could be a potential indicator of cardiovascular disease at the very early stage,whilst monitoring the blood flow dynamics and associated temporal and spatial variations in vessel’s wall shear stress could help predicting the possible rupture of atherosclerotic plaques.The results of feasibility studies of application of DOCT for the evaluation of mechanical properties of elastic vessel model are presented.The technique has also been applied for imaging of sub-cranial rat blood flow in vivo.展开更多
With the introduction of spectral-domain optical coherence tomography(SD-OCT),much larger image datasets are routinely acquired compared to what was possible using the previous generation of time-domain OCT.Thus,there...With the introduction of spectral-domain optical coherence tomography(SD-OCT),much larger image datasets are routinely acquired compared to what was possible using the previous generation of time-domain OCT.Thus,there is a critical need for the development of three-dimensional(3D)segmentation methods for processing these data.We present here a novel 3D automatic segmentation method for retinal OCT volume data.Brie°y,to segment a boundary surface,two OCT volume datasets are obtained by using a 3D smoothingfilter and a 3D differentialfilter.Their linear combination is then calculated to generate new volume data with an enhanced boundary surface,where pixel intensity,boundary position information,and intensity changes on both sides of the boundary surface are used simultaneously.Next,preliminary discrete boundary points are detected from the A-Scans of the volume data.Finally,surface smoothness constraints and a dynamic threshold are applied to obtain a smoothed boundary surface by correcting a small number of error points.Our method can extract retinal layer boundary surfaces sequentially with a decreasing search region of volume data.We performed automatic segmentation on eight human OCT volume datasets acquired from a commercial Spectralis OCT system,where each volume of datasets contains 97 OCT B-Scan images with a resolution of 496512(each B-Scan comprising 512 A-Scans containing 496 pixels);experimental results show that this method can accurately segment seven layer boundary surfaces in normal as well as some abnormal eyes.展开更多
We developed high-speed time-domain (TD) en face optical coherence tomography (OCT) system using KTN optical beam deflector. The KTN optical beam deflector operates at a high repetition rate of 200 kHz with a fairly l...We developed high-speed time-domain (TD) en face optical coherence tomography (OCT) system using KTN optical beam deflector. The KTN optical beam deflector operates at a high repetition rate of 200 kHz with a fairly large beam deflection angle. We proposed a high-speed en face OCT system that used a KTN optical deflector as the sample beam scanning. In the experiment, we obtained en face OCT images of human fingerprint with a frame rate of 800 fps, which is the fastest speed obtained by a TD-OCT imaging. Furthermore, a 3D-OCT image was also obtained at 0.2 s (=5 volumes/s) by our imaging system.展开更多
基金This study was funded by Science and Technology Projects of Guangdong Province(Nos.2019A030317002,2017A030303013,2013B060300003).
文摘Background:A variety of experimental animal models are used in basic ophthalmological research to elucidate physiological mechanisms of vision and disease pathogenesis.The choice of animal model is based on the measurability of specific parameters or structures,the applicability of clinical measurement technologies,and the similarity to human eye function.Studies of eye pathology usually compare optical parameters between a healthy and altered state,so accurate baseline assessments are critical,but few reports have comprehensively examined the normal anatomical structures and physiological functions in these models.Methods:Three cynomolgus monkeys,six New Zealand rabbits,ten Sprague Dawley(SD)rats,and BALB/c mice were examined by fundus photography(FP),fundus fluorescein angiography(FFA),and optical coherence tomography(OCT).Results:Most retinal structures of cynomolgus monkey were anatomically similar to the corresponding human structures as revealed by FP,FFA,and OCT.New Zealand rabbits have large eyeballs,but they have large optic disc and myelinated retinal nerve fibers in their retinas,and the growth pattern of retinal vessels were also different to the human retinas.Unlike monkeys and rabbits,the retinal vessels of SD rats and BALB/c mice were widely distributed and clear.The OCT performance of them were similar with human beings except the macular.Conclusions:Monkey is a good model to study changes in retinal structure associated with fundus disease,rabbits are not suitable for studies on retinal vessel diseases and optic nerve diseases,and rats and mice are good models for retinal vascular diseases.These measures will help guide the choice of model and measurement technology and reduce the number of experimental animals required.
文摘The eye is an immune-privileged and sensory organ in humans and animals.Anatomical,physiological,and pathobiological features share significant similarities across divergent species(1).Each compartment of the eye has a unique structure and function.The anterior and posterior compartments of the eye contain endothelium(cornea),epithelium(cornea,ciliary body,iris),muscle(ciliary body),vitreous and neuronal(retina)tissues,which make the eye suitable to evaluate efficacy and safety of tissue specific drugs(2).
文摘Optical coherence tomography(OCT)is a technology that is widely used to assess structural abnormalities in the retina for a variety of pediatric conditions.The introduction of this instrument has allowed for widespread access to minimally invasive standardized,reproducible quantified structural assessments of the optic nerve and retina.This has had important implications in pediatric optic neuropathies,populations in whom monitoring of disease activity is essential to make treatment decisions.OCT has had particular relevance for inflammatory optic neuropathies,as onset of an inflammatory optic neuropathy may herald the onset of a chronic inflammatory disorder of the central nervous system(CNS)such as multiple sclerosis,neuromyelitis optica spectrum disorder(aquaporin 4 antibody positive),and myelin oligodendrocyte glycoprotein(MOG)associated disorders.This paper will focus on the application of OCT technology to this group of disorders in pediatrics.After reviewing pediatric-specific anatomic and practical issues pertinent to OCT,we will review knowledge related to the use of OCT in inflammatory pediatric optic neuropathies,with a focus on structural outcomes and their correlation with functional outcome metrics.
基金supported by Grants of Russian Science Foundation No.17-75-20069(the part included PDT of brain tumor)and No.18-15-00172(the part included optical monitoring of lymphatic drainage system of the brain)and Ministry of Science and High Education 17.1223.2017/Pchsupported by the Program of Basic Research of the Presidium of the RAS No.32\Nanostructures:Physics,Chemistry,Biology,Basic Technologies."。
文摘Photodynamic therapy(PDT)is a promising tool for least-invasive alternative methods for the treatment of brain tumors.The newly discovered PDT-induced opening of the blood–brain barrier(BBB)permeability open novel strategies for drug-brain delivery during post-surgical treatment of glioblastoma GBM.Here we discuss mechanisms of PDT-mediated opening of the BBB and age differences in PDT-related increase in BBB permeability,including with formation of brain edema.The meningeal lymphatic system plays a crucial role in the mechanism of brain drainage and clearance from metabolites and toxic molecules.We discuss that noninvasive photonic stimulation of°uid clearance via meningeal lymphatic vessels,and application of optical coherence tomography(OCT)for bed-side monitoring of meningeal lymphatic drainage has the promising perspective to be widely applied in both experimental and clinical studies of PDT and improving guidelines of PDT of brain tumors.
基金supported by National Natural Science Foundation of China(No.41476081)the Major Research and Development Project in Shandong Province(No.2019GHY112027)。
文摘Optical coherence tomography(OCT)and Raman spectroscopy(RS)can be complementary biological tissue optical analysis methods.To study the internal structure and tissue compositions of biological samples,an OCT-RS system was built to carry out OCT section imaging and RS analysis in common.Neocaridina denticulate sinensis were collected regularly for morphological observation by OCT imaging and biochemical investigation based on the Raman spectra.The internal structure of the N.denticulate sinensis was imaged by OCT,and the morphology of the tissues and the position in the body were distinguished according to the gray scale changes.The imaging depth along the vertical direction of Z-axis in N.denticulate sinensis is about 1.60 mm.RS detection was selectively performed based on the OCT images.The main Raman peaks of the rostrum,the cephalothorax,the abdominal segment,and the telson section are at 1006,1156,1447,1491 and 1515 cm-1,which are identified as proteins and amino acids.The presence of 1497 cm-1 at the cephalothorax is different from other parts,probably due to the presence of organs such as ovary,whose compositions are different from those of other tissues.The combination of optical coherence tomography and Raman spectroscopy can provide information about morphological and biochemical features of tissues,and has potential applications in biomedical detection and imaging.
文摘Optical coherence tomography (OCT) is a relatively new imaging technology which can produce high resolution images of three-dimensional structures. OCT has been mainly used for medical applications such as for ophthalmology and dermatology. In this study we demonstrate its capability in providing much more reliable biometry identification of fingerprints than conventional methods. We prove that OCT can serve secure control of genuine fingerprints as it can detect if extra layers are placed above the finger. This can prevent with a high probability, intruders to a secure area trying to foul standard systems based on imaging the finger surface. En-Face OCT method is employed and recommended for its capability of providing not only the axial succession of layers in depth, but the en-face image that allows the traditional pattern identification. Another reason for using such OCT technology is that it is compatible with dynamic focus and therefore can provide enhanced transversal resolution and sensitivity. Two En-Face OCT systems are used to evaluate the need for high resolution and conclusions are drawn in terms of the most potential commercial route to ex- ploitation.
文摘Doppler Optical Coherence Tomography(DOCT)is a noninvasive optical diagnostic technique,which is well suited for the quantitative mapping of microflow velocity profiles and the analysis of flow-vessel interactions.The noninvasive imaging and quantitative analysis of blood flow in the complex-structured vascular bed is required in many biomedical applications,including those where the determination of mechanical properties of vessels or the knowledge of the mechanic interactions between the flow and the housing medium plays a key role.The change of microvessel wall elasticity could be a potential indicator of cardiovascular disease at the very early stage,whilst monitoring the blood flow dynamics and associated temporal and spatial variations in vessel’s wall shear stress could help predicting the possible rupture of atherosclerotic plaques.The results of feasibility studies of application of DOCT for the evaluation of mechanical properties of elastic vessel model are presented.The technique has also been applied for imaging of sub-cranial rat blood flow in vivo.
基金This research was supported by the National High Technology Research and Development Program of China("863"Program)under Grant No.2013AA013702the National Natural Science Foundation of China (No.60971006).
文摘With the introduction of spectral-domain optical coherence tomography(SD-OCT),much larger image datasets are routinely acquired compared to what was possible using the previous generation of time-domain OCT.Thus,there is a critical need for the development of three-dimensional(3D)segmentation methods for processing these data.We present here a novel 3D automatic segmentation method for retinal OCT volume data.Brie°y,to segment a boundary surface,two OCT volume datasets are obtained by using a 3D smoothingfilter and a 3D differentialfilter.Their linear combination is then calculated to generate new volume data with an enhanced boundary surface,where pixel intensity,boundary position information,and intensity changes on both sides of the boundary surface are used simultaneously.Next,preliminary discrete boundary points are detected from the A-Scans of the volume data.Finally,surface smoothness constraints and a dynamic threshold are applied to obtain a smoothed boundary surface by correcting a small number of error points.Our method can extract retinal layer boundary surfaces sequentially with a decreasing search region of volume data.We performed automatic segmentation on eight human OCT volume datasets acquired from a commercial Spectralis OCT system,where each volume of datasets contains 97 OCT B-Scan images with a resolution of 496512(each B-Scan comprising 512 A-Scans containing 496 pixels);experimental results show that this method can accurately segment seven layer boundary surfaces in normal as well as some abnormal eyes.
文摘We developed high-speed time-domain (TD) en face optical coherence tomography (OCT) system using KTN optical beam deflector. The KTN optical beam deflector operates at a high repetition rate of 200 kHz with a fairly large beam deflection angle. We proposed a high-speed en face OCT system that used a KTN optical deflector as the sample beam scanning. In the experiment, we obtained en face OCT images of human fingerprint with a frame rate of 800 fps, which is the fastest speed obtained by a TD-OCT imaging. Furthermore, a 3D-OCT image was also obtained at 0.2 s (=5 volumes/s) by our imaging system.
