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Refined Anam-Net:Lightweight Deep Learning Model for Improved Segmentation Performance of Optic Cup and Disc for Glaucoma Diagnosis
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作者 Khursheed Aurangzeb Syed Irtaza Haider Musaed Alhussein 《Computers, Materials & Continua》 SCIE EI 2024年第7期1381-1405,共25页
In this work,we aim to introduce some modifications to the Anam-Net deep neural network(DNN)model for segmenting optic cup(OC)and optic disc(OD)in retinal fundus images to estimate the cup-to-disc ratio(CDR).The CDR i... In this work,we aim to introduce some modifications to the Anam-Net deep neural network(DNN)model for segmenting optic cup(OC)and optic disc(OD)in retinal fundus images to estimate the cup-to-disc ratio(CDR).The CDR is a reliable measure for the early diagnosis of Glaucoma.In this study,we developed a lightweight DNN model for OC and OD segmentation in retinal fundus images.Our DNN model is based on modifications to Anam-Net,incorporating an anamorphic depth embedding block.To reduce computational complexity,we employ a fixed filter size for all convolution layers in the encoder and decoder stages as the network deepens.This modification significantly reduces the number of trainable parameters,making the model lightweight and suitable for resource-constrained applications.We evaluate the performance of the developed model using two publicly available retinal image databases,namely RIM-ONE and Drishti-GS.The results demonstrate promising OC segmentation performance across most standard evaluation metrics while achieving analogous results for OD segmentation.We used two retinal fundus image databases named RIM-ONE and Drishti-GS that contained 159 images and 101 retinal images,respectively.For OD segmentation using the RIM-ONE we obtain an f1-score(F1),Jaccard coefficient(JC),and overlapping error(OE)of 0.950,0.9219,and 0.0781,respectively.Similarly,for OC segmentation using the same databases,we achieve scores of 0.8481(F1),0.7428(JC),and 0.2572(OE).Based on these experimental results and the significantly lower number of trainable parameters,we conclude that the developed model is highly suitable for the early diagnosis of glaucoma by accurately estimating the CDR. 展开更多
关键词 Refined Anam-Net parameter tuning deep learning optic cup optic disc cup-to-disc ratio glaucoma diagnosis
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An Improved Deep Learning Framework for Automated Optic Disc Localization and Glaucoma Detection
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作者 Hela Elmannai Monia Hamdi +3 位作者 Souham Meshoul Amel Ali Alhussan Manel Ayadi Amel Ksibi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1429-1457,共29页
Glaucoma disease causes irreversible damage to the optical nerve and it has the potential to cause permanent loss of vision.Glaucoma ranks as the second most prevalent cause of permanent blindness.Traditional glaucoma... Glaucoma disease causes irreversible damage to the optical nerve and it has the potential to cause permanent loss of vision.Glaucoma ranks as the second most prevalent cause of permanent blindness.Traditional glaucoma diagnosis requires a highly experienced specialist,costly equipment,and a lengthy wait time.For automatic glaucoma detection,state-of-the-art glaucoma detection methods include a segmentation-based method to calculate the cup-to-disc ratio.Other methods include multi-label segmentation networks and learning-based methods and rely on hand-crafted features.Localizing the optic disc(OD)is one of the key features in retinal images for detecting retinal diseases,especially for glaucoma disease detection.The approach presented in this study is based on deep classifiers for OD segmentation and glaucoma detection.First,the optic disc detection process is based on object detection using a Mask Region-Based Convolutional Neural Network(Mask-RCNN).The OD detection task was validated using the Dice score,intersection over union,and accuracy metrics.The OD region is then fed into the second stage for glaucoma detection.Therefore,considering only the OD area for glaucoma detection will reduce the number of classification artifacts by limiting the assessment to the optic disc area.For this task,VGG-16(Visual Geometry Group),Resnet-18(Residual Network),and Inception-v3 were pre-trained and fine-tuned.We also used the Support Vector Machine Classifier.The feature-based method uses region content features obtained by Histogram of Oriented Gradients(HOG)and Gabor Filters.The final decision is based on weighted fusion.A comparison of the obtained results from all classification approaches is provided.Classification metrics including accuracy and ROC curve are compared for each classification method.The novelty of this research project is the integration of automatic OD detection and glaucoma diagnosis in a global method.Moreover,the fusion-based decision system uses the glaucoma detection result obtained using several convolutional deep neural networks and the support vector machine classifier.These classification methods contribute to producing robust classification results.This method was evaluated using well-known retinal images available for research work and a combined dataset including retinal images with and without pathology.The performance of the models was tested on two public datasets and a combined dataset and was compared to similar research.The research findings show the potential of this methodology in the early detection of glaucoma,which will reduce diagnosis time and increase detection efficiency.The glaucoma assessment achieves about 98%accuracy in the classification rate,which is close to and even higher than that of state-of-the-art methods.The designed detection model may be used in telemedicine,healthcare,and computer-aided diagnosis systems. 展开更多
关键词 optic disc GLAUCOMA fundus image deep learning
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Automated evaluation of parapapillary choroidal microvasculature in crowded optic discs:a controlled,optical coherence tomography angiography study
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作者 Hatice Arda Hidayet Sener +5 位作者 Ozge Temizyurek Hatice Kubra Sonmez Duygu Gulmez Sevim Cem Evereklioglu Fatih Horozoglu Ayse Busra Gunay Sener 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第1期113-118,共6页
AIM:To compare superficial and deep vascular properties of optic discs between crowded discs and controls using optical coherence tomography angiography(OCT-A).METHODS:Thirty patients with crowded discs,and 47 control... AIM:To compare superficial and deep vascular properties of optic discs between crowded discs and controls using optical coherence tomography angiography(OCT-A).METHODS:Thirty patients with crowded discs,and 47 control subjects were enrolled in the study.One eye of each individual was included and OCT-A scans of optic discs were obtained in a 4.5×4.5 mm^(2) rectangular area.Radial peripapillary capillary(RPC)density,peripapillary retinal nerve fiber layer(pRNFL)thickness,cup volume,rim area,disc area,cup-to-disc(c/d)area ratio,and vertical c/d ratio were obtained automatically using device software.Automated parapapillary choroidal microvasculature(PPCMv)density was calculated using MATLAB software.When the vertical c/d ratio of the optic disc was absent or small cup,it was considered as a crowded disc.RESULTS:The mean signal strength index of OCT-A images was similar between the crowded discs and control eyes(P=0.740).There was no difference in pRNFL between the two groups(P=0.102).There were no differences in RPC density in whole image(P=0.826)and peripapillary region(P=0.923),but inside disc RPC density was higher in crowded optic discs(P=0.003).The PPCMv density in the inner-hemisuperior region was also lower in crowded discs(P=0.026).The pRNFL thickness was positively correlated with peripapillary RPC density(r=0.498,P<0.001).The inside disc RPC density was negatively correlated with c/d area ratio(r=-0.341,P=0.002).CONCLUSION:The higher inside disc RPC density and lower inner-hemisuperior PPCMv density are found in eyes with crowded optic discs. 展开更多
关键词 crowded optic disc ischemic optic neuropathy optical coherence tomography angiography parapapillary choroidal microvasculature
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Late Diagnosis of Congenital Optic Disc Abnormalities
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作者 Aïssatou Aw Soda Mbaye +9 位作者 Jean Pierre Diagne Sy El Hadji Malick Alassane Ba Aly Mbara Ka Serigne Sohibou Gaye Ousmane Ndiaga Senghor Lamine Ndiaye Mouhamed Ndiaye El Hadj Abdellahi Seyid Papa Amadou Ndiaye 《Open Journal of Ophthalmology》 2024年第3期229-235,共7页
Purpose: To show epidemiological and imaging aspects of congenital optic disc abnormalities diagnosed late. Method: It was a retrospective study, including all patients with congenital optic disc abnormalities diagnos... Purpose: To show epidemiological and imaging aspects of congenital optic disc abnormalities diagnosed late. Method: It was a retrospective study, including all patients with congenital optic disc abnormalities diagnosed at a late age between January 2020 and October 2022 at the eye center of Abass Ndao Hospital. Complete ophthalmological examination was performed with eye imaging according to the cases. Results: 09 patients (10 eyes) were diagnosed with congenital optic disc abnormalities. The mean age was 29 years, with a sex ratio of 0.8. Three patients had consulted for unilateral decreased visual acuity since childhood, two for sudden vision loss and in four cases the diagnosis was fortuitous. Visual acuity was ranged from 1/200 to 20/20. Fundus examination showed myelinated retinal nerve fibers in four eyes, optic disc pit in three eyes including two complicated by maculopathy, two cases of morning glory syndrome and a case of pseudoduplication of the optic disc. Optical coherence tomography, ocular ultrasound B and OCT-Angiography were performed according to the cases. Conclusion: Congenital optic disc abnormalities are often diagnosed late. They are potentially amblyogenic and complications are not rare, worsening the visual prognosis. Their screening should be systematic by ophthalmological examination in newborns. 展开更多
关键词 Myelinated Nerves Fibers optic disc Pit Morning Glory Syndrome Pseudoduplication optic disc
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Birth Defects of the Child Optic Disc: Diagnostic Challenges and Prospects for Care
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作者 Prudence Ada Assoumou Davy Alex Mouinga Abayi +4 位作者 Annick Kougou Ntoutoume Hélène Nyinko Aboughe Olive Matsanga Tatiana Harly Mba Aki Emmanuel Mve Mengome 《Open Journal of Ophthalmology》 2024年第2期128-135,共8页
Introduction: Congenital optic disc anomalies in children refer to structural variations of the optic nerve head present from birth. These deformations involve the size, shape, color, and vessels of the optic disc. Al... Introduction: Congenital optic disc anomalies in children refer to structural variations of the optic nerve head present from birth. These deformations involve the size, shape, color, and vessels of the optic disc. Although often asymptomatic, these anomalies can impact the visual development of the child, underscoring the importance of a thorough fundus examination for early detection and appropriate medical follow-up. We present two cases of congenital optic disc anomalies in children, illustrating the diagnostic challenges and complexity of their management. Case 1: A 3-year-old girl presented with a white spot in her left eye present since birth. Uncorrected distance visual acuity was 2/10 in the right eye, while she could perceive hand movements at 2 meters with the left eye. Normal examination in the right eye showed leukocoria, microphthalmia, and a white mass at the center of the optic disc on fundus examination in the left eye. Ocular imaging, including ultrasound and optical coherence tomography (OCT), confirmed the diagnosis of persistent hyperplastic primary vitreous (PHPV) in its mixed form in the left eye. Management included prescribing full optical correction and functional rehabilitation, without resorting to surgery. The course was marked by persistent amblyopia leading to a poor prognosis. Case 2: A 7-year-old girl consulted for vision disturbance in her right eye. Visual acuity was finger counting at 2 meters in the right eye and 10/10 in the left eye. Anterior segment examination revealed no abnormalities in both eyes. However, fundus examination highlighted a large funnel-shaped excavation associated with central glial proliferation, wheel spoke vessels, and neuroretinal ring atrophy in the right eye. Optical coherence tomography (OCT) of the right eye confirmed the diagnosis of isolated unilateral Morning Glory syndrome. Management included full optical correction and orthoptic rehabilitation. The course was marked by the absence of ocular complication and maintenance of visual stability in the right eye. The prognosis seemed favorable. Conclusion: Congenital optic disc anomalies in children exhibit great clinical variability and require an individualized diagnostic and therapeutic approach. 展开更多
关键词 optic disc PHPV Morning Glory DIAGNOSIS Treatment
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Quantitative analysis of optic disc changes in school-age children with ametropia based on artificial intelligence 被引量:2
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作者 Fang Liu Xing-Hui Yu +4 位作者 Yu-Chuan Wang Miao Cao Lian-Feng Xie Jing Liu Lin-Lin Liu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第11期1727-1733,共7页
AIM:To explore changes in the optic disc and peripapillary atrophy(PPA)in school-age children with ametropia using color fundus photography combined with artificial intelligence(AI)technology.METHODS:Based on the retr... AIM:To explore changes in the optic disc and peripapillary atrophy(PPA)in school-age children with ametropia using color fundus photography combined with artificial intelligence(AI)technology.METHODS:Based on the retrospective case-controlled study,226 eyes of 113 children aged aged 6–12y were enrolled from October 2021 to May 2022.According to the results of spherical equivalent(SE),the children were divided into four groups:low myopia group(66 eyes),moderate myopia group(60 eyes),high myopia group(50 eyes)and emmetropia control group(50 eyes).All subjects underwent un-aided visual acuity,dilated pupil optometry,best-corrected visual acuity(BCVA),intraocular pressure,ocular axis measurement and color fundus photography.RESULTS:The width of PPA,horizontal diameter ratio of PPA to the optic disc and area ratio of PPA to the optic disc were significantly different among the four groups(P<0.05).The width of the nasal and temporal neuroretinal rim,the roundness of the optic disc,the height of PPA,the vertical diameter ratio of PPA to the optic disc,and the average density of PPA in the high myopia group were significantly different compared with the other three groups(P<0.05).There were strong negative correlations between SE and area ratio of PPA to the optic disc(r=-0.812,P<0.001)and strong positive correlation between axial length(AL)and area ratio of PPA to the optic disc(r=0.736,P<0.001).CONCLUSION:In school-age children with high myopia,the nasal and temporal neuroretinal rims are narrowed and even lost,which have high sensitivity.The area ratio of the PPA to the optic disc could be used as an early predictor of myopia progression,which is of great significance for the development prevention and management of myopia. 展开更多
关键词 optic disc artificial intelligence AMETROPIA peripapillary atrophy spherical equivalent
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Automatic Optic Disc Detection in Retinal Images Using FKMT‒MOPDF
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作者 Kittipol Wisaeng 《Computer Systems Science & Engineering》 SCIE EI 2023年第6期2569-2586,共18页
In recent days,detecting Optic Disc(OD)in retinal images has been challenging and very important to the early diagnosis of eye diseases.The process of detecting the OD is challenging due to the diversity of color,inte... In recent days,detecting Optic Disc(OD)in retinal images has been challenging and very important to the early diagnosis of eye diseases.The process of detecting the OD is challenging due to the diversity of color,intensity,brightness and shape of the OD.Moreover,the color similarities of the neighboring organs of the OD create difficulties during OD detection.In the proposed Fuzzy K‒Means Threshold(FKMT)and Morphological Operation with Pixel Density Feature(MOPDF),the input retinal images are coarsely segmented by fuzzy K‒means clustering and thresholding,in which the OD is classified from its neighboring organs with intensity similarities.Then,the segmented images are given as the input to morphological operation with pixel density feature calculations,which reduce the false detection in the small pixel of the OD.Finally,the OD area is detected by applying the Sobel edge detection method,which accurately detects the OD from the retinal images.After detection optimization,the proposed method achieved Sensitivity(SEN),Specificity(SPEC)and Accuracy(ACC),with 96.74%,96.78%and 96.92%in DiaretDB0(Standard Diabetic Retinopathy Database Calibration level 0),97.12%,97.10%and 97.75%in DiaretDB1(Standard Diabetic Retinopathy Database Calibration level 1)and 97.19%,97.47%and 97.43%in STARE(Structured Analysis of the Retina)dataset respectively.The experimental results demonstrated the proposed method’s efficiency for segmenting and detecting OD areas. 展开更多
关键词 optic disc fuzzy K-means clustering SEGMENTATION morphological operation pixel density feature calculation
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Intravitreal Ranibizumab Combined with Sulfotanshinone Sodium Injection in Treating Type II Optic Disc Vasculitis
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作者 Bingwen Lu Xingwei Wu Lei Zhang 《Case Reports in Clinical Medicine》 2016年第11期494-499,共7页
Objectives: To present the effect of intravitreal ranibizumab (IVR) therapy combined with sulfotanshinone sodium (SS) injection in a patient suffering from type II optic disc vasculitis (ODV). Methods: A 26-year-old f... Objectives: To present the effect of intravitreal ranibizumab (IVR) therapy combined with sulfotanshinone sodium (SS) injection in a patient suffering from type II optic disc vasculitis (ODV). Methods: A 26-year-old female patient was diagnosed with type II ODV with macular edema (ME). The information was obtained by complete medical and ophthalmic history taking and a detailed ophthalmic examination at the initial and follow-up visits. Functional and morphological outcomes at baseline, 1 week and 1 month following IVR+SS injections, are presented. Results: Best-corrected visual acuity (BCVA) improved from 78 letters (ETDRS) at baseline to 90 letters at 1-week follow-up and maintained stable through 1-month follow-up. Central retinal thickness (CRT) measured by optical coherence tomography (OCT) decreased from 465 μm at baseline to 240 μm at 1-week follow-up and to 226 μm at 1-month follow-up. Mean deviation (MD) measured by perimetry increased from ?5.17 dB to ?4.59 dB and to ?4.29 dB, respectively. Fluorescein angiography (FFA) showed that the initial macular edema at baseline disappeared while the arm-retina circulation time (ART) was also greatly shortened when compared to the baseline. Electroretinogram (ERG) measured at 1-month follow-up demonstrated an overall improvement of the retinal function after the injection. No ocular or systemic side effects were detected. Conclusions: IVR+SS injection may lead to resolution of the associated ME and improve the retina morphologically as well as functionally. To our knowledge, this is the first case of a type II ODV benefiting from treatment with IVR+SS injection. The observed results warrant further investigation. 展开更多
关键词 Intravitreal Ranibizumab Sulfotanshinone Sodium Injection Type II optic disc Vasculitis
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Optic disc and peripapillary changes by optic coherence tomography in high myopia 被引量:3
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作者 Ting Pan Yun Su +3 位作者 Song-Tao Yuan Hang-Cheng Lu Zi-Zhong Hu Qing-Huai Liu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第5期874-880,共7页
Myopia,a worldwide condition,is a multifactorial disease resulting in many ocular complications.Early onset of myopia has a great tendency to develop high myopia and pathological myopia later in life.The pathophysiolo... Myopia,a worldwide condition,is a multifactorial disease resulting in many ocular complications.Early onset of myopia has a great tendency to develop high myopia and pathological myopia later in life.The pathophysiology and progression of myopia is still unclear.Owing to its involving in visual function,optic disc and peripapillary change in high myopia can't be neglected,and it may help in better understanding of the pathophysiology or mechanism of myopia progression.Recently,advanced imaging techniques have been developed,such as optical coherence tomography(OCT),allowing for better detecting of optic disc and peripapillary change.OCT is a highresolution and noninvasive measurement for detection of ocular structure.Herein,we provide an updated review of optic disc and peripapillary change in OCT image,including its characteristics and clinical significance.We also propose some problems needed further investigation. 展开更多
关键词 high myopia optical coherence tomography optic disc peripapillary
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Serous macular detachment due to nasally located optic disc pit-coloboma 被引量:2
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作者 Sofia Theodoropoulou George Theodossiadis +1 位作者 Ahmed Sallam Panagiotis Theodossiadis 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第11期1879-1880,共2页
Dear Editor,We present the first reported case of nasal optic disc pit resulting in serous detachment of the macula. Optic disc pit is a rare congenital anomaly occurring in one out of 11 000 people. The appearance is... Dear Editor,We present the first reported case of nasal optic disc pit resulting in serous detachment of the macula. Optic disc pit is a rare congenital anomaly occurring in one out of 11 000 people. The appearance is a localized round or oval depression in that is grey, yellow or black in colour depending on the amount of glial tissue present. 展开更多
关键词 SAS Serous macular detachment due to nasally located optic disc pitcoloboma
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Optic disc area in different types of glaucoma 被引量:1
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作者 Oya Tekeli Esra Savku Ahmed Abdullayev 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第8期1134-1137,共4页
AIMTo evaluate the possible relationship of optic disc area with retina nerve fiber layer in different glaucoma subtypes.METHODSOne eye each was chosen from 45 patients with ocular hypertension, 45 patients with prima... AIMTo evaluate the possible relationship of optic disc area with retina nerve fiber layer in different glaucoma subtypes.METHODSOne eye each was chosen from 45 patients with ocular hypertension, 45 patients with primary open angle glaucoma, 45 patients with pseudoexfoliation glaucoma and 45 healthy controls followed in our hospital. The records of the patients were reviewed retrospectively. Optic disc area and circumpapillary retina nerve fiber layer measurements were obtained using optical coherence tomography. Central corneal thickness was measured by ultrasound pachymetry.RESULTSThe median disc area in the patients with primary open angle glaucoma was significantly higher than the patients with ocular hypertension (2.19 vs 1.90 mm<sup>2</sup>, P=0.030). The median retina nerve fiber layer was thinner in the patients with primary open angle glaucoma and pseudoexfoliation glaucoma than the patients with ocular hypertension for superior, inferior and temporal quadrants. After adjustment for age, no difference in central corneal thickness was found between the groups. Greater disc area was associated with thicker retinal nerve fiber layer for superior, inferior and nasal quadrants in the patients with primary open angle glaucoma. There was no correlation between disc area and central corneal thickness measurements of the groups.CONCLUSIONDisc size affects the retinal nerve fiber layer thickness in eyes with primary open angle glaucoma and is a possible risk factor for glaucomatous optic nerve damage. 展开更多
关键词 central corneal thickness ocular hypertension optic disc area primary open angle glaucoma pseudoexfoliation glaucoma retina nerve fiber layer
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Transient Symptomatic Bilateral Optic Disc Oedema Following Lumbar Spinal Surgery— An Unusual Presentation 被引量:1
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作者 Vijaya Jojo Surendra Prasad Jakhanwal 《Open Journal of Ophthalmology》 2017年第2期124-128,共5页
Background: Optic disc oedema has various underlying pathologies, however, unless visually disabling does not usually bring a patient to the physician. The more common symptoms of headache, nausea and vomiting lead to... Background: Optic disc oedema has various underlying pathologies, however, unless visually disabling does not usually bring a patient to the physician. The more common symptoms of headache, nausea and vomiting lead to the incidental detection of bilateral disc oedema [1]. Optic disc oedema seen following spinal surgery is usually associated with visual acuity changes and often goes by the acronym POVL (Peri/ postoperative visual loss) wherein, as the name goes, visual acuity changes are profound [2] [3] [4]. Purpose: We would like to highlight a case of transient Bilateral Optic Disc oedema following Lumbar spinal surgery maintaining normal visual acuity and attaining spontaneous resolution. Case Report: A 42-year-old female presented with transient obscuration of vision and flashes of light post an uneventful lumbar spinal surgery. Ophthalmic evaluation revealed normal visual acuity and pupils but marked disc edema right more significant than left. There was no colour vision deficit, neither any field changes. By a process of exclusion, it was likely the patient had developed bilateral disc oedema secondary to the spinal surgery. On follow-up 6 weeks and 3 months later, the oedema had completely settled and visual acuity remained at 6/6. Conclusion: Optic disc oedema can be unilateral or bilateral with some of the uncommon conditions mentioned secondary to spinal surgery, however, in those situations, visual loss has been severe and permanent. Our case is unusual in its combination of disc edema with normal acuity along with its transient nature and resolution and to our knowledge, has not been published before. 展开更多
关键词 TRANSIENT optic disc OEDEMA LUMBAR SPINAL Surgery Normal Visual ACUITY
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NDC-IVM:An automatic segmentation of optic disc and cup region from medical images for glaucoma detection 被引量:1
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作者 Umarani Balakrishnan 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2017年第3期118-132,共15页
Glaucoma is an eye disease that usually occurs with the increased Intra-Ocular Pressure(IOP),which damages the vision of eyes.So,detecting and classifying Glaucoma is an important and demanding task in recent days.For... Glaucoma is an eye disease that usually occurs with the increased Intra-Ocular Pressure(IOP),which damages the vision of eyes.So,detecting and classifying Glaucoma is an important and demanding task in recent days.For this purpose,some of the clustering and segmentation techniques are proposed in the existing works.But,it has some drawbacks that include ineficient,inaccurate and estimates only the affected area.In order to solve these issues,a Neighboring Differential Clustering(NDC)-Intensity V ariation Making(IVM)are proposed in this paper.The main intention of this work is to extract and diagnose the abnormal retinal image by identifying the optic disc.This work includes three stages such as,preprocessing,clustering and segmentation.At first,the given retinal image is preprocessed by using the Gaussian Mask Updated(GMU)model for eliminating the noise and improving the quality of the image.Then,the cluster is formed by extracting the threshold and patterns with the help of NDC technique.In the segmentation stage,the weight is calculated for pixel matching and ROI extraction by using the proposed IVM method.Here,the novelty is presented in the clustering and segmentation processes by developing NDC and IVM algorithms for accurate Glaucoma identification.In experiments,the results of both existing and proposed techniques are evaluated in terms of sensitivity,specificity,accuracy,Hausdorff distance,Jaccard and dice metrics. 展开更多
关键词 Glaucoma detection optic disc Gaussian mask updated neighboring differential clustering intensity variation masking retinal image.
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The Influence of Surgical and Medical Interventions upon Optic Disc Structure in Patients with Primary Open Angle Glaucoma 被引量:2
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作者 Hui Xiao Xing Liu Yimin Zhong Zhen Mao 《Eye Science》 CAS 2011年第4期185-192,共8页
Purpose:To evaluate the changes of optic disc parameters in primary open angle glaucoma(POAG)patients after surgical and medical treatment,.and analyze the determinants of these changes.Methods:.A total of 67 patients... Purpose:To evaluate the changes of optic disc parameters in primary open angle glaucoma(POAG)patients after surgical and medical treatment,.and analyze the determinants of these changes.Methods:.A total of 67 patients were enrolled in this study.Thirty nine patients.(40 eyes) underwent trabeculectomy and 28 patients(32 eyes).received intra-ocular pressure(IOP) lowering medical therapy..All subjects underwent bilateral routine ocular examination and Heidelberg retina tomography.(HRT) before treatment and 2 weeks,.1 month,3 months,.6 months and 1 year after treatment..Changes in optic disc parameters in both the surgical and medical groups were analyzed,as was the influence of disease severity and IOP reduction on these changes.Results:.In the surgical group,the average preoperative IOP was 32.8±8.64 mmHg,.which showed a significant decline at each post-operative visit..Most optic disc parameters measured by HRT were significantly improved after trabeculectomy.(P=0.001~0.01),.though the amount of improvement declined gradually during the post-operative period.Rim volume (RV),cup shape measure (CSM),mean RNFL (mRNFL),RNFL cross sectional area (RNFLA) and vertical cup-to-disc ratio (C/D) still remained significantly below the pre-operative mean one year after surgery.In the medical group,the mean IOP before treatment was 24.8±4.32 mmHg and remained < 21 mmHg on all subsequent post-treatment visits.However,no significant changes in optic disc parameters were found after initiation of medical treatment(F=0.52~2.21,P=0.75~0.07).In the surgical group,the extent of reduction of IOP was positively correlated with the improvement in RV,CSM and vertical C/D(r=0.41~0.58,P=0.001~0.04) at one year after trabeculectomy.The absolute value of the mean deviation on visual field testing was negatively correlated with the improvement of RV and CSM (r=-0.43~-0.62,P=0.03~0.001).Conclusion:Improvement in optic disc parameters occurred more commonly after surgical than medical treatment in POAG patients.The amount of reduction of IOP was correlated with the extent of this improvement,which may be more limited in more severe glaucoma. 展开更多
关键词 青光眼 原发性 手术 视盘 医疗 患者 药物治疗 平均偏差
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Agreement in identification of glaucomatous progression between the optic disc photography and Heidelberg Retina Tomography in young glaucomatous patients
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作者 Paraskeva Hentova-Sencanic Ivan Sencanic +2 位作者 Goran Trajkovic Marija Bozic Nevena Bjelovic 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2014年第3期474-479,共6页
AIM:To evaluate concordance between the clinical assessment of glaucomatous progression of the optic disc photography and progression identified by Heidelberg Retina Tomograph(HRT)in patients with suspected primary ju... AIM:To evaluate concordance between the clinical assessment of glaucomatous progression of the optic disc photography and progression identified by Heidelberg Retina Tomograph(HRT)in patients with suspected primary juvenile open angle glaucoma(JOAG).METHODS:Optic disc photographs and corresponding HRTⅡseries were reviewed.Optic disc changes between first and final photographs were noted as well as progression identified by HRT topographic change analysis(TCA)and rim area regression line(RARL)Agreement between progression indentified by photography and HRT methods was assessed.Progression,determined from optic disc photographs by consensus assessment was used as the reference standard.RESULTS:A total of 31 patients(59 eyes)with suspected JOAG were studied.Agreement for progression/no progression between TCA and photography was obtained in 4 progressing eyes and 38stable eyes(71.19%,k=0.11).Agreement for progression/no progression between RARL and photography was detected in 5 progressing eyes and in 34 stable eyes(66.10%,k=0.15).The number of HRT per patient was statistically higher in the progressing group(P=0.034).CONCLUSION:Agreement for detection of longitudinal changes between photography and HRT analysis was poor.One way to improve the chance of discovery of the progression could be increasing the number of HRT examinations. 展开更多
关键词 optic disc juvenile glaucoma Heidelberg Retina Tomography
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Second Approximation Model for Optical Head in Super High Density Storage Technology
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作者 Wu Wan Pei Xian-deng 《Wuhan University Journal of Natural Sciences》 CAS 2000年第2期155-158,共4页
The paper presents second approximation model for optical head in super high-density storage technology firstly and it is an important part for three grades approximate model of ultra-small-size quantum well corn-shap... The paper presents second approximation model for optical head in super high-density storage technology firstly and it is an important part for three grades approximate model of ultra-small-size quantum well corn-shaped laser and simulative calculations. It supplies the important and useful results for the NFOD optical head design with ultra thin active layer and ultra small spot laser. 展开更多
关键词 near field optical disc corn-shaped laser multilayer quantum well mode analysis
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Automated Detection of Optic Disc from Digital Retinal Fundus Images for Screening Systems of Diabetic Retinopathy
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作者 GAO Weiwei MA Xiaofeng ZUO Jing 《Journal of Donghua University(English Edition)》 EI CAS 2020年第1期74-79,共6页
Optic disc(OD)detection is a main step while developing automated screening systems for diabetic retinopathy.We present a method to automatically locate and extract the OD in digital retinal fundus images.Based on the... Optic disc(OD)detection is a main step while developing automated screening systems for diabetic retinopathy.We present a method to automatically locate and extract the OD in digital retinal fundus images.Based on the property that main blood vessels gather in OD,the method starts with Otsu thresholding segmentation to obtain candidate regions of OD.Consequently,the main blood vessels which are segmented in H channel of color fundus images in Hue saturation value(HSV)space.Finally,a weighted vessels’direction matched filter is proposed to roughly match the direction of the main blood vessels to get the OD center which is used to pick the true OD out from the candidate regions of OD.The proposed method was evaluated on a dataset containing 100 fundus images of both normal and diseased retinas and the accuracy reaches 98%.Furthermore,the average time cost in processing an image is 1.3 s.Results suggest that the approach is reliable,and can efficiently detect OD from fundus images. 展开更多
关键词 FUNDUS image spectral characteristics analysis optic disc(od) blood vessels OTSU THRESHOLDING MATCH filter segmentation
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Optic Disc Drusen in a Child Diagnosed with Alport Syndrome—Case Report
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作者 Adamu Sambo Mona Aslam Syam Padmanabha 《Open Journal of Nephrology》 2014年第4期142-145,共4页
Optic disc drusen are eye abnormalities characterised by calcific degeneration affecting some axons of the optic nerve. Alport syndrome is a collagen IV related nephropathy with well-described pathognomonic ocular fea... Optic disc drusen are eye abnormalities characterised by calcific degeneration affecting some axons of the optic nerve. Alport syndrome is a collagen IV related nephropathy with well-described pathognomonic ocular features. We present the case of a child who following series of investigations was found to have bilateral optic disc drusen, and eventually a further diagnosis of Alport syndrome confirmed. Literature is clear on the underlined aetiology responsible for both renal and extra renal abnormalities of Alport syndrome, which is not related to development of optic disc drusen. The case described makes it pertinent that not only the associated eye signs of Alport syndrome are monitored, but also early detection of other possible co-existing diseases that may influence outcomes. 展开更多
关键词 Alport SYNDROME optic disc DRUSEN Pseudopapilloedema
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SCANNING TUNNELING MICROSCOPY STUDIES ON OPTICAL DISC
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作者 徐磊 张兰平 +10 位作者 张益 要小未 张桂根 徐耀良 于新根 黄泽琪 李民乾 顾冬红 陈启英 吴章华 干福熹 《Nuclear Science and Techniques》 SCIE CAS CSCD 1994年第4期212-214,共3页
Scanning tunneling microscope (STM) is used to investigate the optical disc.The areas with and without data stampers are all observed carefully. Three-dimensional images of the disc surface clearly demonstrate the per... Scanning tunneling microscope (STM) is used to investigate the optical disc.The areas with and without data stampers are all observed carefully. Three-dimensional images of the disc surface clearly demonstrate the period, depth of the grooves and the shape of data stampers. Some phenomena of STM imaging are also discussed. 展开更多
关键词 STM TOPOGRAPHY optical disc
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Combined Hamartoma of the Optic Disc and Retinal Pigment Epithelium—3 Years of the Follow-Up with Semi-Automated Kinetic Perimetry
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作者 Katarzyna Nowomiejska Tomasz Zarnowski +1 位作者 Robert Rejdak Anselm Juenemann 《Open Journal of Ophthalmology》 2012年第4期116-118,共3页
Aim: To present a case of hamartoma of the optic disc and Retinal Pigment Epithelium (RPE) and follow up of the visual function over three-years period. Methods: A seventeen-year-old boy has observed reduced visual ac... Aim: To present a case of hamartoma of the optic disc and Retinal Pigment Epithelium (RPE) and follow up of the visual function over three-years period. Methods: A seventeen-year-old boy has observed reduced visual acuity in his left eye. The visual acuity was 0.2 and there was RAPD in the left eye. Fundoscopy revealed an elevation of the optic disc obscuring disc vessels with epiretinal gliosis. Fluorescein angiography demonstrated hyperfluorescent saccular dilatations with leakage in the late phase. Ocular Coherence Tomography (OCT) showed hyperreflective elevation of the optic disc and epiretinal membrane. There was a juxtapapillary scotoma in Semi-automated Kinetic Perimetry (SKP). There was no systemic diseases. Results of blood tests, CT and MRI of CNV were normal. Results: After 3 years period of the follow-up the visual acuity was 0.1 and there was a progression of the visual field defect to the altitudinal scotoma in the upper hemisphere. Fluorescein anhiography and OCT revealed the same. Conclusion: Hamartoma of RPE and optic disc is a rare condition consisting of glial, vascular and RPE cells. It should be differentiated from optic disc oedema and vascular tumors of the retina. Assessment of the visual function is very important in the longitudinal follow-up. 展开更多
关键词 HAMARTOMA PERIMETRY optic disc
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