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
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
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
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 widely used non-invasive medical imaging technology that has revolutionized clinical care in ophthalmology.New developments,such as OCT angiography(OCTA)are expected to contribute...Optical coherence tomography(OCT)is a widely used non-invasive medical imaging technology that has revolutionized clinical care in ophthalmology.New developments,such as OCT angiography(OCTA)are expected to contribute even further to the widespread use of OCT-based imaging devices in the diagnosis and monitoring of patients with ophthalmic diseases.In recent years,many of the disadvantages such as limited field of view and imaging artefacts have been substantially reduced.Similar to the progress achieved in the assessment of retinal disorders,OCT is expected to change the approach to patients seen in the neuro-ophthalmology clinic.In this article,we review the technical features of OCT and OCT-based imaging techniques,highlighting the specific factors that should be taken into account when interpreting OCT in the field of neuro-ophthalmology.展开更多
Hereditary,metabolic and toxic optic neuropathies cause bilateral,central vision loss and therefore can result in severe impairment in visual function.Accurate,early diagnosis is critical,as nutritional and toxic opti...Hereditary,metabolic and toxic optic neuropathies cause bilateral,central vision loss and therefore can result in severe impairment in visual function.Accurate,early diagnosis is critical,as nutritional and toxic optic neuropathies may be reversible if identified early,and diagnosis of hereditary optic neuropathies can prevent unnecessary invasive workup,provide prognostic information,and allow for effective genetic counseling.Optical coherence tomography(OCT)is a valuable tool that aids in the diagnosis and prognostication of optic neuropathies as it allows for quantification of changes in the retinal ganglion cells(RGCs)and retinal nerve fiber layer(RNFL)over time.We review the characteristic clinical presentations of hereditary,metabolic and toxic optic neuropathies,with an emphasis on OCT findings.展开更多
Optical coherence tomography(OCT)is an ocular imaging technique that can complement the neuro-ophthalmic assessment,and inform our understanding regarding functional consequences of neuroaxonal injury in the afferent ...Optical coherence tomography(OCT)is an ocular imaging technique that can complement the neuro-ophthalmic assessment,and inform our understanding regarding functional consequences of neuroaxonal injury in the afferent visual pathway.Indeed,OCT has emerged as a surrogate end-point in the diagnosis and follow up of several demyelinating syndromes of the central nervous system(CNS),including optic neuritis(ON)associated with:multiple sclerosis(MS),neuromyelitis optica spectrum disorder(NMOSD),and anti-myelin oligodendrocyte glycoprotein(MOG)antibodies.Recent advancements in enhanced depth imaging(EDI)OCT have distinguished this technique as a new gold standard in the diagnosis of optic disc drusen(ODD).Moreover,OCT may enhance our ability to distinguish cases of papilledema from pseudopapilledema caused by ODD.In the setting of idiopathic intracranial hypertension(IIH),OCT has shown benefit in tracking responses to treatment,with respect to reduced retinal nerve fiber layer(RNFL)measures and morphological changes in the angling of Bruch’s membrane.Longitudinal follow up of OCT measured ganglion cell-inner plexiform layer thickness may be of particular value in managing IIH patients who have secondary optic atrophy.Causes of compressive optic neuropathies may be readily diagnosed with OCT,even in the absence of overt visual field defects.Furthermore,OCT values may offer some prognostic value in predicting post-operative outcomes in these patients.Finally,OCT can be indispensable in differentiating optic neuropathies from retinal diseases in patients presenting with vision loss,and an unrevealing fundus examination.In this review,our over-arching goal is to highlight the potential role of OCT,as an ancillary investigation,in the diagnosis and management of various optic nerve disorders.展开更多
Background:Basal cell carcinoma(BCC)accounts for 90%of the eyelid malignancies followed by sebaceous cell carcinoma(SC)and squamous cell carcinoma(SCC).Even though biopsy for histopathological(HP)evaluation remains th...Background:Basal cell carcinoma(BCC)accounts for 90%of the eyelid malignancies followed by sebaceous cell carcinoma(SC)and squamous cell carcinoma(SCC).Even though biopsy for histopathological(HP)evaluation remains the gold standard for confirming the diagnosis of eyelid tumors and the status of surgical margins,noninvasive techniques such as dermoscopy and optical coherence tomography(OCT)may increase diagnostic sensitivity and contribute to more accurate delineation of surgical margins.The purpose of this prospective study was to correlate the HP and OCT findings of eyelid malignancies.Methods:After ethics committee approval(BCC/2017-2608),patients with suspected eyelid carcinomas had photographs taken,tumor characteristics assessed clinically and using dermoscopy and OCT,which were subsequently compared with HP evaluation.We obtained OCT images of periorbital tumors with an anterior segment lens adjusted in an Optovue Avanti.The histopathology was evaluated using a digital pathology system.Patients under 18 years old were excluded from this study.Results:Three female and three male patients(age 69-88 years)with lesions located in the lower periorbital area(n=5)and upper eyelid(n=1)were included in this study.Two participants previously had skin cancer:1 female patient had a lentigo maligna and a BCC,and 1 male patient had multiple BCC and actinic keratosis due to immunosuppression related to a liver transplant.Clinical and dermoscopicc diagnosis were accurate in four cases:3 BCC and 1 SCC.One clinically suspicious BCC was diagnosed as SC and one patient had a previous confirmed diagnosis of SC.All OCT images showed disruption of the dermoepidermal junction and hyporeflective areas in the dermis,which were darker and well-delineated in the three confirmed BCCs.OCT also clearly demarcated the transition between tumor and normal skin in all cases.Conclusions:OCT is a fast and non-invasive exam to acquire high-resolution images of intraocular and ocular surface structures.Preliminary data from our study indicates that real-time OCT images correlate with HP findings and may also help delineate tumor margins.The inclusion of additional participants will provide further evidence of the benefits of using OCT pre-operatively to safely minimize surgical margins during eyelid tumor excision.展开更多
Optical coherence tomography angiography(OCTA),an extent function of traditional optical coherence tomography(OCT),is a non-invasive,high-resolution imaging system designed to display vascular networks.The fundamental...Optical coherence tomography angiography(OCTA),an extent function of traditional optical coherence tomography(OCT),is a non-invasive,high-resolution imaging system designed to display vascular networks.The fundamental principle of OCTA is to achieve the signal of blood flow based on the analysis of complex OCT signal,amplitude of OCT signal or phase of OCT signal.OCTA can display and monitor the vascular abnormalities in patients with diabetic retinopathy(DR),including microaneurysms,vessel density(VD),nonperfusion,neovascularization,and other lesions.OCTA offers a new and potential horizon in the monitor of the DR progress and evaluation of DR treatment.展开更多
Optical coherence tomography(OCT)angiography is a new non-invasive imaging modality which is providing clinicians with an alternative to traditional dye-based angiography.The images are obtained using the concept of m...Optical coherence tomography(OCT)angiography is a new non-invasive imaging modality which is providing clinicians with an alternative to traditional dye-based angiography.The images are obtained using the concept of motion contrast and provide a quicker safer way to image the retinal and choroidal circulation.Not only are there practical aspects to support its integration but new insights are being made into the path;hysiology of various retinal choroidal diseases due to its ability to provide a 3-dimensional view of the vasculature which can be segmented in many ways to focus in on the circulation of a given anatomic region of the retina.We are currently in the phase of integration of this new technology into our practices.展开更多
Idiopathic intracranial hypertension(IIH)is a condition in which elevated pressure in the cerebrospinal fluid can lead to optic nerve head(ONH)dysfunction and subsequent visual impairment.Physicians are currently limi...Idiopathic intracranial hypertension(IIH)is a condition in which elevated pressure in the cerebrospinal fluid can lead to optic nerve head(ONH)dysfunction and subsequent visual impairment.Physicians are currently limited in their ability to monitor and manage this condition,as clinical symptoms and exam findings are often delayed in response to changes in intracranial pressure.In order to find other biomarkers of disease,researchers are using imaging modalities such as optical coherence tomography(OCT)to observe microscopic changes in the eye in this condition.OCT can create 2-dimensional and 3-dimensional high definition images of the retina of the ONH and has been used to study various conditions such as glaucoma and multiple sclerosis.Numerous studies have used OCT in IIH as well,and they have shown that certain retinal layers and the ONH change in thickness and shape in both the short and long term with intracranial pressure changes.OCT is a promising modality for clinical and scientific evaluation of IIH as it is a noninvasive and practical tool to obtain in depth images.This review will discuss how OCT can be used to assess a patient with IIH,both before and after treatment,along with its limitations and future applications.展开更多
To present spectral domain optical coherence tomography(OCT)findings during treatment in a case of acute isolated cilioretinal artery occlusion(CLRAO)reversed with intravenous systemic administration of mannitol and c...To present spectral domain optical coherence tomography(OCT)findings during treatment in a case of acute isolated cilioretinal artery occlusion(CLRAO)reversed with intravenous systemic administration of mannitol and carbogen inhalation.Close monitoring with OCT thickness topographic map and cross section scans,every 12 hours,during treatment and till complete reversal of retinal nerve fiber layer edema.Fundus photography and fluorescein angiography(FFA)were used to illustrate occlusion and recanalization.After 72 hours of therapy,visual acuity improved from counting fingers(CF)to 7/10,Snellen’s chart.Consecutively OCT scans showed that the initial macular edema was gradually restored to typical 72 hours of treatment initiation.FFA performed after treatment confirmed recanalization of the cilioretinal artery.Early intervention with the combined intravenous administration of mannitol and carbogen inhalation can reverse acute onset loss of vision due to CLRAO.The reflectivity of retinal layers differs significantly regarding stages of acute CLRAO.In our case report increased reflectivity of the innermost layers of the retina was illustrated and a corresponding reduction in the outer retina and the retinal pigment epithelium and choriocapillaris layers.Macular thickness follow-up data recorded the course of intracellular edema to normal.展开更多
Based on anisotropic total variation regularization(ATVR), a nonnegativity and support constraints recursive inverse filtering(NAS-RIF) blind restoration method is proposed to enhance the quality of optical coherence ...Based on anisotropic total variation regularization(ATVR), a nonnegativity and support constraints recursive inverse filtering(NAS-RIF) blind restoration method is proposed to enhance the quality of optical coherence tomography(OCT) image. First, ATVR is introduced into the cost function of NAS-RIF to improve the noise robustness and retain the details in the image.Since the split Bregman iterative is used to optimize the ATVR based cost function, the ATVR based NAS-RIF blind restoration method is then constructed. Furthermore, combined with the geometric nonlinear diffusion filter and the Poisson-distribution-based minimum error thresholding, the ATVR based NAS-RIF blind restoration method is used to realize the blind OCT image restoration. The experimental results demonstrate that the ATVR based NAS-RIF blind restoration method can successfully retain the details in the OCT images. In addition, the signal-to-noise ratio of the blind restored OCT images can be improved, along with the noise robustness.展开更多
Background:Over the years,a variety of non-invasive techniques have been developed to allow the measurement of blood flow in living human eyes.However,none of the existing techniques has yet been adopted in clinical p...Background:Over the years,a variety of non-invasive techniques have been developed to allow the measurement of blood flow in living human eyes.However,none of the existing techniques has yet been adopted in clinical practice due to their limitations and lack of standardization.Moreover,no reliable technique is currently available to measure the pulsatile choroidal blood flow(PCBF).We propose a novel method based on video-rate optical coherence tomography(OCT)imaging and automated segmentation to measure the pulsatile component of choroidal blood flow in vivo,and demonstrate its repeatability.Methods:Adapted from our earlier work(Beaton et al.),this method uses video-rate OCT with enhanced depth imaging and automated segmentation of the choroid to measure the pulsatile choroidal volume change.Imaging is carried out at the fundus for less than a minute at 7 Hz.In each frame,choroidal thickness(CT)is measured by a segmentation algorithm based on graph cuts using an edge-probability weighting scheme.The algorithm computes the CT change corresponding to choroidal filling over the time-series and subsequently derives the pulsatile choroidal volume change through an approximate model of the eye.Fifty-eight subjects were recruited from the Maisonneuve-Rosemont Hospital and PCBF was measured twice in one eye within the same session and by a single examiner.Repeatability was assessed using the Bland-Altman plot and Intraclass correlation coefficient as calculated with SPSS.Results:Two measurements of PCBF were successfully obtained for each eye using our technique.The average measures ICC for choroidal volume change was 0.929(95%CI,0.881,0.958),showing good to excellent repeatability.The Bland-Altman plot and Pearson coefficient(r=0.840,P<0.001)showed agreement and a strong correlation respectively between intra-session measurement of OR in all examined eyes.Conclusions:This study confirms the high repeatability of pulsatile choroidal blood flow measurements obtained with our optical method,allowing further investigation of blood flow in ocular diseases such as glaucoma and AMD.展开更多
Background:The aim of this project is to develop a new standardized and cost-efficient method to compare optical coherence tomography(OCT)scans to their corresponding paraffin embedded histopathology sections in post-...Background:The aim of this project is to develop a new standardized and cost-efficient method to compare optical coherence tomography(OCT)scans to their corresponding paraffin embedded histopathology sections in post-mortem eyes.This correlation will clarify the interpretation of OCT images,and it will also enable direct immunohistochemical characterization of features observed on OCT.Methods:Study design:donor eyes were obtained from two separate eye banks.In order to minimize post-mortem change like retinal detachment and vitreous opacification,the eyes were fixed in a previously tested fixative solution.Time between death and fixation has been kept under 6 hours.Methods:Using a customized imaging device,nine post-mortem eyes were imaged with a SD-OCT machine.Subsequently,an 8mm trephine was used to isolate a portion of the posterior pole including the macular area and the optic nerve head for histopathological analysis.Paraffin embedded cross sections of the retina were obtained and visually compared to each OCT image(b-scans).Results:To facilitate the correlation of OCT images to their histopathological sections,three principle aspects were controlled during tissue processing:rotation,tilt and location.Using markings as well as anatomical landmarks,serial histopathological sections in an orientation comparable to OCT b-scans were obtained,thereby facilitating image pairing.Conclusions:Compared to other well-established methods using resin and electron microscopy,our standardized Methods allowed us to successfully compare OCT b-scans to serial retinal cross sections of a wider macular area at a lower cost.Our novel approach allows us to translate features observed on OCT images into well-established histopathological images,providing the clinician with additional tools to obtain difficult diagnoses with more confidence.展开更多
This paper reports on the latest advances in line-field confocal optical cohere nee tomography(LC-OCT),a recently invented imaging technology that now allows the generation of either horizontal(x×y)section images...This paper reports on the latest advances in line-field confocal optical cohere nee tomography(LC-OCT),a recently invented imaging technology that now allows the generation of either horizontal(x×y)section images at an adjustable depth or vertical(x×z)section images at an adjustable lateral position,as well as thre dimensional images.For both two-dimensional imaging modes,images are acquired in real-time,with real-time control of the depth and lateral positions.Three-dimensional(x×y×z)images are acquired from a stack of horizontal section images.The device is in the form of a portable probe.The handle of the probe has a button and a scroll wheel allowing the user to control the imaging modes.Using a supercontinuum laser as a broadband light source and a high numerical microscope objective,an isotropic spatial resolution of^1|im is achieved.The field of view of the three-dimensional images is 1.2 mm×0.5 mm×0.5 mm(x×y×z).Images of skin tissues are presented to demonstrate the potential of the technology in dermatology.展开更多
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).
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 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 widely used non-invasive medical imaging technology that has revolutionized clinical care in ophthalmology.New developments,such as OCT angiography(OCTA)are expected to contribute even further to the widespread use of OCT-based imaging devices in the diagnosis and monitoring of patients with ophthalmic diseases.In recent years,many of the disadvantages such as limited field of view and imaging artefacts have been substantially reduced.Similar to the progress achieved in the assessment of retinal disorders,OCT is expected to change the approach to patients seen in the neuro-ophthalmology clinic.In this article,we review the technical features of OCT and OCT-based imaging techniques,highlighting the specific factors that should be taken into account when interpreting OCT in the field of neuro-ophthalmology.
基金This work was supported by an unrestricted grant from the Research to Prevent Blindness to the Washington University Department of Ophthalmology and Visual Sciences,and by a Research Award from the Vitreoretinal Surgery Foundation(JE).
文摘Hereditary,metabolic and toxic optic neuropathies cause bilateral,central vision loss and therefore can result in severe impairment in visual function.Accurate,early diagnosis is critical,as nutritional and toxic optic neuropathies may be reversible if identified early,and diagnosis of hereditary optic neuropathies can prevent unnecessary invasive workup,provide prognostic information,and allow for effective genetic counseling.Optical coherence tomography(OCT)is a valuable tool that aids in the diagnosis and prognostication of optic neuropathies as it allows for quantification of changes in the retinal ganglion cells(RGCs)and retinal nerve fiber layer(RNFL)over time.We review the characteristic clinical presentations of hereditary,metabolic and toxic optic neuropathies,with an emphasis on OCT findings.
文摘Optical coherence tomography(OCT)is an ocular imaging technique that can complement the neuro-ophthalmic assessment,and inform our understanding regarding functional consequences of neuroaxonal injury in the afferent visual pathway.Indeed,OCT has emerged as a surrogate end-point in the diagnosis and follow up of several demyelinating syndromes of the central nervous system(CNS),including optic neuritis(ON)associated with:multiple sclerosis(MS),neuromyelitis optica spectrum disorder(NMOSD),and anti-myelin oligodendrocyte glycoprotein(MOG)antibodies.Recent advancements in enhanced depth imaging(EDI)OCT have distinguished this technique as a new gold standard in the diagnosis of optic disc drusen(ODD).Moreover,OCT may enhance our ability to distinguish cases of papilledema from pseudopapilledema caused by ODD.In the setting of idiopathic intracranial hypertension(IIH),OCT has shown benefit in tracking responses to treatment,with respect to reduced retinal nerve fiber layer(RNFL)measures and morphological changes in the angling of Bruch’s membrane.Longitudinal follow up of OCT measured ganglion cell-inner plexiform layer thickness may be of particular value in managing IIH patients who have secondary optic atrophy.Causes of compressive optic neuropathies may be readily diagnosed with OCT,even in the absence of overt visual field defects.Furthermore,OCT values may offer some prognostic value in predicting post-operative outcomes in these patients.Finally,OCT can be indispensable in differentiating optic neuropathies from retinal diseases in patients presenting with vision loss,and an unrevealing fundus examination.In this review,our over-arching goal is to highlight the potential role of OCT,as an ancillary investigation,in the diagnosis and management of various optic nerve disorders.
文摘Background:Basal cell carcinoma(BCC)accounts for 90%of the eyelid malignancies followed by sebaceous cell carcinoma(SC)and squamous cell carcinoma(SCC).Even though biopsy for histopathological(HP)evaluation remains the gold standard for confirming the diagnosis of eyelid tumors and the status of surgical margins,noninvasive techniques such as dermoscopy and optical coherence tomography(OCT)may increase diagnostic sensitivity and contribute to more accurate delineation of surgical margins.The purpose of this prospective study was to correlate the HP and OCT findings of eyelid malignancies.Methods:After ethics committee approval(BCC/2017-2608),patients with suspected eyelid carcinomas had photographs taken,tumor characteristics assessed clinically and using dermoscopy and OCT,which were subsequently compared with HP evaluation.We obtained OCT images of periorbital tumors with an anterior segment lens adjusted in an Optovue Avanti.The histopathology was evaluated using a digital pathology system.Patients under 18 years old were excluded from this study.Results:Three female and three male patients(age 69-88 years)with lesions located in the lower periorbital area(n=5)and upper eyelid(n=1)were included in this study.Two participants previously had skin cancer:1 female patient had a lentigo maligna and a BCC,and 1 male patient had multiple BCC and actinic keratosis due to immunosuppression related to a liver transplant.Clinical and dermoscopicc diagnosis were accurate in four cases:3 BCC and 1 SCC.One clinically suspicious BCC was diagnosed as SC and one patient had a previous confirmed diagnosis of SC.All OCT images showed disruption of the dermoepidermal junction and hyporeflective areas in the dermis,which were darker and well-delineated in the three confirmed BCCs.OCT also clearly demarcated the transition between tumor and normal skin in all cases.Conclusions:OCT is a fast and non-invasive exam to acquire high-resolution images of intraocular and ocular surface structures.Preliminary data from our study indicates that real-time OCT images correlate with HP findings and may also help delineate tumor margins.The inclusion of additional participants will provide further evidence of the benefits of using OCT pre-operatively to safely minimize surgical margins during eyelid tumor excision.
基金This work was supported by grants from the National Key Basic Research Program of China(973 Program:2013CB967000)the National Natural Science Foundation of China to YAN LUO(81371020).
文摘Optical coherence tomography angiography(OCTA),an extent function of traditional optical coherence tomography(OCT),is a non-invasive,high-resolution imaging system designed to display vascular networks.The fundamental principle of OCTA is to achieve the signal of blood flow based on the analysis of complex OCT signal,amplitude of OCT signal or phase of OCT signal.OCTA can display and monitor the vascular abnormalities in patients with diabetic retinopathy(DR),including microaneurysms,vessel density(VD),nonperfusion,neovascularization,and other lesions.OCTA offers a new and potential horizon in the monitor of the DR progress and evaluation of DR treatment.
文摘Optical coherence tomography(OCT)angiography is a new non-invasive imaging modality which is providing clinicians with an alternative to traditional dye-based angiography.The images are obtained using the concept of motion contrast and provide a quicker safer way to image the retinal and choroidal circulation.Not only are there practical aspects to support its integration but new insights are being made into the path;hysiology of various retinal choroidal diseases due to its ability to provide a 3-dimensional view of the vasculature which can be segmented in many ways to focus in on the circulation of a given anatomic region of the retina.We are currently in the phase of integration of this new technology into our practices.
基金This work was supported by an unrestricted grant for Research to Prevent Blindness to the Stanford Department of Ophthalmology and National Institutes of Health(grant number P30 EY026877)to HE Moss.
文摘Idiopathic intracranial hypertension(IIH)is a condition in which elevated pressure in the cerebrospinal fluid can lead to optic nerve head(ONH)dysfunction and subsequent visual impairment.Physicians are currently limited in their ability to monitor and manage this condition,as clinical symptoms and exam findings are often delayed in response to changes in intracranial pressure.In order to find other biomarkers of disease,researchers are using imaging modalities such as optical coherence tomography(OCT)to observe microscopic changes in the eye in this condition.OCT can create 2-dimensional and 3-dimensional high definition images of the retina of the ONH and has been used to study various conditions such as glaucoma and multiple sclerosis.Numerous studies have used OCT in IIH as well,and they have shown that certain retinal layers and the ONH change in thickness and shape in both the short and long term with intracranial pressure changes.OCT is a promising modality for clinical and scientific evaluation of IIH as it is a noninvasive and practical tool to obtain in depth images.This review will discuss how OCT can be used to assess a patient with IIH,both before and after treatment,along with its limitations and future applications.
文摘To present spectral domain optical coherence tomography(OCT)findings during treatment in a case of acute isolated cilioretinal artery occlusion(CLRAO)reversed with intravenous systemic administration of mannitol and carbogen inhalation.Close monitoring with OCT thickness topographic map and cross section scans,every 12 hours,during treatment and till complete reversal of retinal nerve fiber layer edema.Fundus photography and fluorescein angiography(FFA)were used to illustrate occlusion and recanalization.After 72 hours of therapy,visual acuity improved from counting fingers(CF)to 7/10,Snellen’s chart.Consecutively OCT scans showed that the initial macular edema was gradually restored to typical 72 hours of treatment initiation.FFA performed after treatment confirmed recanalization of the cilioretinal artery.Early intervention with the combined intravenous administration of mannitol and carbogen inhalation can reverse acute onset loss of vision due to CLRAO.The reflectivity of retinal layers differs significantly regarding stages of acute CLRAO.In our case report increased reflectivity of the innermost layers of the retina was illustrated and a corresponding reduction in the outer retina and the retinal pigment epithelium and choriocapillaris layers.Macular thickness follow-up data recorded the course of intracellular edema to normal.
基金Supported by National Key Research and Development Program of China(2016YFF0201005)。
文摘Based on anisotropic total variation regularization(ATVR), a nonnegativity and support constraints recursive inverse filtering(NAS-RIF) blind restoration method is proposed to enhance the quality of optical coherence tomography(OCT) image. First, ATVR is introduced into the cost function of NAS-RIF to improve the noise robustness and retain the details in the image.Since the split Bregman iterative is used to optimize the ATVR based cost function, the ATVR based NAS-RIF blind restoration method is then constructed. Furthermore, combined with the geometric nonlinear diffusion filter and the Poisson-distribution-based minimum error thresholding, the ATVR based NAS-RIF blind restoration method is used to realize the blind OCT image restoration. The experimental results demonstrate that the ATVR based NAS-RIF blind restoration method can successfully retain the details in the OCT images. In addition, the signal-to-noise ratio of the blind restored OCT images can be improved, along with the noise robustness.
文摘Background:Over the years,a variety of non-invasive techniques have been developed to allow the measurement of blood flow in living human eyes.However,none of the existing techniques has yet been adopted in clinical practice due to their limitations and lack of standardization.Moreover,no reliable technique is currently available to measure the pulsatile choroidal blood flow(PCBF).We propose a novel method based on video-rate optical coherence tomography(OCT)imaging and automated segmentation to measure the pulsatile component of choroidal blood flow in vivo,and demonstrate its repeatability.Methods:Adapted from our earlier work(Beaton et al.),this method uses video-rate OCT with enhanced depth imaging and automated segmentation of the choroid to measure the pulsatile choroidal volume change.Imaging is carried out at the fundus for less than a minute at 7 Hz.In each frame,choroidal thickness(CT)is measured by a segmentation algorithm based on graph cuts using an edge-probability weighting scheme.The algorithm computes the CT change corresponding to choroidal filling over the time-series and subsequently derives the pulsatile choroidal volume change through an approximate model of the eye.Fifty-eight subjects were recruited from the Maisonneuve-Rosemont Hospital and PCBF was measured twice in one eye within the same session and by a single examiner.Repeatability was assessed using the Bland-Altman plot and Intraclass correlation coefficient as calculated with SPSS.Results:Two measurements of PCBF were successfully obtained for each eye using our technique.The average measures ICC for choroidal volume change was 0.929(95%CI,0.881,0.958),showing good to excellent repeatability.The Bland-Altman plot and Pearson coefficient(r=0.840,P<0.001)showed agreement and a strong correlation respectively between intra-session measurement of OR in all examined eyes.Conclusions:This study confirms the high repeatability of pulsatile choroidal blood flow measurements obtained with our optical method,allowing further investigation of blood flow in ocular diseases such as glaucoma and AMD.
文摘Background:The aim of this project is to develop a new standardized and cost-efficient method to compare optical coherence tomography(OCT)scans to their corresponding paraffin embedded histopathology sections in post-mortem eyes.This correlation will clarify the interpretation of OCT images,and it will also enable direct immunohistochemical characterization of features observed on OCT.Methods:Study design:donor eyes were obtained from two separate eye banks.In order to minimize post-mortem change like retinal detachment and vitreous opacification,the eyes were fixed in a previously tested fixative solution.Time between death and fixation has been kept under 6 hours.Methods:Using a customized imaging device,nine post-mortem eyes were imaged with a SD-OCT machine.Subsequently,an 8mm trephine was used to isolate a portion of the posterior pole including the macular area and the optic nerve head for histopathological analysis.Paraffin embedded cross sections of the retina were obtained and visually compared to each OCT image(b-scans).Results:To facilitate the correlation of OCT images to their histopathological sections,three principle aspects were controlled during tissue processing:rotation,tilt and location.Using markings as well as anatomical landmarks,serial histopathological sections in an orientation comparable to OCT b-scans were obtained,thereby facilitating image pairing.Conclusions:Compared to other well-established methods using resin and electron microscopy,our standardized Methods allowed us to successfully compare OCT b-scans to serial retinal cross sections of a wider macular area at a lower cost.Our novel approach allows us to translate features observed on OCT images into well-established histopathological images,providing the clinician with additional tools to obtain difficult diagnoses with more confidence.
文摘This paper reports on the latest advances in line-field confocal optical cohere nee tomography(LC-OCT),a recently invented imaging technology that now allows the generation of either horizontal(x×y)section images at an adjustable depth or vertical(x×z)section images at an adjustable lateral position,as well as thre dimensional images.For both two-dimensional imaging modes,images are acquired in real-time,with real-time control of the depth and lateral positions.Three-dimensional(x×y×z)images are acquired from a stack of horizontal section images.The device is in the form of a portable probe.The handle of the probe has a button and a scroll wheel allowing the user to control the imaging modes.Using a supercontinuum laser as a broadband light source and a high numerical microscope objective,an isotropic spatial resolution of^1|im is achieved.The field of view of the three-dimensional images is 1.2 mm×0.5 mm×0.5 mm(x×y×z).Images of skin tissues are presented to demonstrate the potential of the technology in dermatology.
