AIM： To describe retinal findings of various imaging modalities in acute retinal ischemia. METHODS： Fluorescein angiography（FA）, spectral domain optical coherence tomography（SD-OCT）, OCTangiography（OCT-A） and ...AIM： To describe retinal findings of various imaging modalities in acute retinal ischemia. METHODS： Fluorescein angiography（FA）, spectral domain optical coherence tomography（SD-OCT）, OCTangiography（OCT-A） and fundus autofluorescence（FAF） images of 13 patients（mean age 64y, range 28-86y） with acute retinal ischemia were evaluated. Six suffered from branch arterial occlusion, 2 had a central retinal artery occlusion, 2 had a combined arteriovenous occlusions, 1 patient had a retrobulbar arterial compression by an orbital haemangioma and 2 patients showed an ocular ischemic syndrome.RESULTS： All patients showed increased reflectivity and thickening of the ischemic retinal tissue. In 10 out of 13 patients SD-OCT revealed an additional highly reflective band located within or above the outer plexiform layer. Morphological characteristics were a decreasing intensity with distance from the fovea, partially segmental occurrence and manifestation limited in time. OCT-A showed a loss of flow signal in the superficial and deep capillary plexus at the affected areas. Reduced flow signal was detected underneath the regions with retinal edema. FAF showed areas of altered signal intensity at the posterior pole. The regions of decreased FAF signal corresponded to peri-venous regions. CONCLUSION： Multimodal imaging modalities in retinal ischemia yield characteristic findings and valuable diagnostic information. Conventional OCT identifies hyperreflectivity and thickening and a mid-retinal hyperreflective band is frequently observed. OCT-A examination reveals demarcation of the ischemic retinal area on the vascular level. FAF shows decreased fluorescence signal in areas of retinal edema often corresponding to peri-venous regions.展开更多
Several features of retinal vessels can be used to monitor the progression of diseases. Changes in vascular structures, for example, vessel caliber, branching angle, and tortuosity, are portents of many diseases such ...Several features of retinal vessels can be used to monitor the progression of diseases. Changes in vascular structures, for example, vessel caliber, branching angle, and tortuosity, are portents of many diseases such as diabetic retinopathy and arterial hypertension. This paper proposes an automatic retinal vessel segmentation method based on morphological closing and multi-scale line detection. First, an illumination correction is performed on the green band retinal image. Next, the morphological closing and subtraction processing are applied to obtain the crude retinal vessel image. Then, the multi-scale line detection is used to fine the vessel image. Finally, the binary vasculature is extracted by the Otsu algorithm, in this paper, for improving the drawbacks of multi-scale line detection, only the line detectors at 4 scales are used. The experimental results show that the accuracy is 0.939 for DRIVE （digital retinal images for vessel extraction） retinal database, which is much better than other methods.展开更多
Cerebral small vessel disease(SVD)involves ischemic white matter damage and choroid plexus(CP)dysfunction for cerebrospinal fluid(CSF)production.Given the vascular and CSF links between the eye and brain,this study ex...Cerebral small vessel disease(SVD)involves ischemic white matter damage and choroid plexus(CP)dysfunction for cerebrospinal fluid(CSF)production.Given the vascular and CSF links between the eye and brain,this study explored whether retinal vascular morphology can indicate cerebrovascular injury and CP dysfunction in SVD.We assessed SVD burden using imaging phenotypes like white matter hyperintensities(WMH),perivascular spaces,lacunes,and microbleeds.Cerebrovascular injury was quantified by WMH volume and peak width of skeletonized mean diffusivity(PSMD),while CP volume measured its dysfunction.Retinal vascular markers were derived from fundus images,with associations analyzed using generalized linear models and Pearson correlations.Path analysis quantified contributions of cerebrovascular injury and CP volume to retinal changes.Support vector machine models were developed to predict SVD severity using retinal and demographic data.Among 815 participants,578 underwent ocular imaging.Increased SVD burden markedly correlated with both cerebral and retinal biomarkers,with retinal alterations equally influenced by cerebrovascular damage and CP enlargement.Machine learning models showed robust predictive power for severe SVD burden(AUC was 0.82),PSMD(0.81),WMH volume(0.77),and CP volume(0.80).These findings suggest that retinal imaging could serve as a cost-effective,noninvasive tool for SVD screening based on vascular and CSF connections.展开更多
The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial...The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial amygdala(Me A). However, whether conventional RGCs(c RGCs) project to the Me A remains unknown. The goal of this study was to determine if c RGCs project to the Me A and to determine the morphological properties of Me A-projecting RGCs(Me A-RGCs). Retrogradely labeled RGCs in whole-mount retinas were intracellularly injected to reveal their dendritic morphologies. Immunohistochemical staining was performed to selectively label ip RGCs(Me A-ip RGCs) and c RGCs(Me A-c RGCs). The results showed that 95.7% of the retrogradely labeled cells were c RGCs and that the rest were ip RGCs. Specifically, Me A-c RGCs consist of two morphological types. The majority of them exhibit small but dense dendritic fields and diffuse ramification patterns as previously reported in RG_(B2)(95%), while the rest exhibit small but sparse dendritic branching patterns resembling those of RG_(B3) cells(5%). Me Aip RGCs consist of M1 and M2 subtypes. The Me A-RGCs showed an even retinal distribution patterns. The soma and dendritic field sizes of the Me A-RGCs did not vary with eccentricity. In conclusion, the present results suggest that Me A-RGCs are structurally heterogeneous. These direct RGCs that input to the Me A could be important for regulating amygdala functions.展开更多
文摘AIM： To describe retinal findings of various imaging modalities in acute retinal ischemia. METHODS： Fluorescein angiography（FA）, spectral domain optical coherence tomography（SD-OCT）, OCTangiography（OCT-A） and fundus autofluorescence（FAF） images of 13 patients（mean age 64y, range 28-86y） with acute retinal ischemia were evaluated. Six suffered from branch arterial occlusion, 2 had a central retinal artery occlusion, 2 had a combined arteriovenous occlusions, 1 patient had a retrobulbar arterial compression by an orbital haemangioma and 2 patients showed an ocular ischemic syndrome.RESULTS： All patients showed increased reflectivity and thickening of the ischemic retinal tissue. In 10 out of 13 patients SD-OCT revealed an additional highly reflective band located within or above the outer plexiform layer. Morphological characteristics were a decreasing intensity with distance from the fovea, partially segmental occurrence and manifestation limited in time. OCT-A showed a loss of flow signal in the superficial and deep capillary plexus at the affected areas. Reduced flow signal was detected underneath the regions with retinal edema. FAF showed areas of altered signal intensity at the posterior pole. The regions of decreased FAF signal corresponded to peri-venous regions. CONCLUSION： Multimodal imaging modalities in retinal ischemia yield characteristic findings and valuable diagnostic information. Conventional OCT identifies hyperreflectivity and thickening and a mid-retinal hyperreflective band is frequently observed. OCT-A examination reveals demarcation of the ischemic retinal area on the vascular level. FAF shows decreased fluorescence signal in areas of retinal edema often corresponding to peri-venous regions.
基金supported by the NSC under Grant NSC 102-2221-E-005-082
文摘Several features of retinal vessels can be used to monitor the progression of diseases. Changes in vascular structures, for example, vessel caliber, branching angle, and tortuosity, are portents of many diseases such as diabetic retinopathy and arterial hypertension. This paper proposes an automatic retinal vessel segmentation method based on morphological closing and multi-scale line detection. First, an illumination correction is performed on the green band retinal image. Next, the morphological closing and subtraction processing are applied to obtain the crude retinal vessel image. Then, the multi-scale line detection is used to fine the vessel image. Finally, the binary vasculature is extracted by the Otsu algorithm, in this paper, for improving the drawbacks of multi-scale line detection, only the line detectors at 4 scales are used. The experimental results show that the accuracy is 0.939 for DRIVE （digital retinal images for vessel extraction） retinal database, which is much better than other methods.
基金partially supported by the R&D Program of Beijing Municipal Education Commission(KM202410025017)National Natural Science Foundation of China(62171297,61931013,and 82272072)+3 种基金Natural Science Foundation of Beijing Municipality(7242267)Beijing Scholars Program([2015]160)Nature Cultivation Fund of Capital Medical University(PYZ23035)Research Incubation Fund of Yanjing Medical College of Capital Medical University(23kypyz02).
文摘Cerebral small vessel disease(SVD)involves ischemic white matter damage and choroid plexus(CP)dysfunction for cerebrospinal fluid(CSF)production.Given the vascular and CSF links between the eye and brain,this study explored whether retinal vascular morphology can indicate cerebrovascular injury and CP dysfunction in SVD.We assessed SVD burden using imaging phenotypes like white matter hyperintensities(WMH),perivascular spaces,lacunes,and microbleeds.Cerebrovascular injury was quantified by WMH volume and peak width of skeletonized mean diffusivity(PSMD),while CP volume measured its dysfunction.Retinal vascular markers were derived from fundus images,with associations analyzed using generalized linear models and Pearson correlations.Path analysis quantified contributions of cerebrovascular injury and CP volume to retinal changes.Support vector machine models were developed to predict SVD severity using retinal and demographic data.Among 815 participants,578 underwent ocular imaging.Increased SVD burden markedly correlated with both cerebral and retinal biomarkers,with retinal alterations equally influenced by cerebrovascular damage and CP enlargement.Machine learning models showed robust predictive power for severe SVD burden(AUC was 0.82),PSMD(0.81),WMH volume(0.77),and CP volume(0.80).These findings suggest that retinal imaging could serve as a cost-effective,noninvasive tool for SVD screening based on vascular and CSF connections.
基金supported by the National Nature Science Foundation of China(81401102 to Liju Luan)National Nature Science Foundation of China(31571091 to Mingliang Pu)the National Basic Research Program of China(2016CB351806 to Mingliang Pu)
文摘The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial amygdala(Me A). However, whether conventional RGCs(c RGCs) project to the Me A remains unknown. The goal of this study was to determine if c RGCs project to the Me A and to determine the morphological properties of Me A-projecting RGCs(Me A-RGCs). Retrogradely labeled RGCs in whole-mount retinas were intracellularly injected to reveal their dendritic morphologies. Immunohistochemical staining was performed to selectively label ip RGCs(Me A-ip RGCs) and c RGCs(Me A-c RGCs). The results showed that 95.7% of the retrogradely labeled cells were c RGCs and that the rest were ip RGCs. Specifically, Me A-c RGCs consist of two morphological types. The majority of them exhibit small but dense dendritic fields and diffuse ramification patterns as previously reported in RG_(B2)(95%), while the rest exhibit small but sparse dendritic branching patterns resembling those of RG_(B3) cells(5%). Me Aip RGCs consist of M1 and M2 subtypes. The Me A-RGCs showed an even retinal distribution patterns. The soma and dendritic field sizes of the Me A-RGCs did not vary with eccentricity. In conclusion, the present results suggest that Me A-RGCs are structurally heterogeneous. These direct RGCs that input to the Me A could be important for regulating amygdala functions.
