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1.
Zhonghua Yan Ke Za Zhi ; 58(1): 46-48, 2022 Jan 11.
Artigo em Chinês | MEDLINE | ID: mdl-34979793

RESUMO

A diabetic patient complained of sudden visual field defect on the third day after cataract surgery. The fundus examination showed optic disc edema in the left eye, which was diagnosed as anterior ischemic optic neuropathy by optical coherence tomography and visual field examinations. The optic neuropathy was induced by the excessive application of tropicamide phenylephrine eye drops by herself before cataract surgery. After timely treatment, the patient's vision and visual field recovered well.


Assuntos
Catarata , Diabetes Mellitus , Neuropatia Óptica Isquêmica , Fundo de Olho , Humanos , Neuropatia Óptica Isquêmica/etiologia , Acuidade Visual
2.
Comput Methods Programs Biomed ; 213: 106530, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34813984

RESUMO

BACKGROUND AND OBJECTIVES: Glaucoma can cause irreversible vision loss and even blindness, and early diagnosis can help prevent vision loss. Analyzing the optic disc and optic cup helps diagnose glaucoma, which motivates many computer-aided diagnosis methods based on deep learning networks. However, the performance of the trained model on new datasets is seriously hindered due to the distribution gap between different datasets. Therefore, we aim to develop an unsupervised learning method to solve this problem and improve the prediction performance of the model on new datasets. METHODS: In this paper, we propose a novel unsupervised model based on adversarial learning to perform the optic disc and cup segmentation and glaucoma screening tasks in a more generalized and efficient manner. We adopt an efficient segmentation and classification network and employ unsupervised domain adaptation technology on the output space of the segmentation network to solve the domain shift problem. We conduct glaucoma screening task by combining classification and segmentation networks to obtain more stable and efficient glaucoma screening prediction. RESULTS: We verify the effectiveness and efficiency of our proposed method on three public datasets, the REFUGE, DRISHTI-GS and RIM-ONE-r3 datasets. The experimental results demonstrate that the proposed method can effectively alleviate the deterioration of segmentation performance caused by domain shift and improve the accuracy of glaucoma screening. Furthermore, the proposed method outperforms state-of-the-art unsupervised optic disc and cup segmentation domain adaptation methods. CONCLUSIONS: The proposed method can assist clinicians in screening and diagnosis of glaucoma and is suitable for real-world applications.


Assuntos
Glaucoma , Disco Óptico , Diagnóstico por Computador , Técnicas de Diagnóstico Oftalmológico , Fundo de Olho , Glaucoma/diagnóstico , Humanos
3.
Indian J Ophthalmol ; 70(1): 296-298, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34937260

RESUMO

We describe an effective surgical approach for the management of cilioretinal artery occlusion. A 23-G pars plana vitrectomy assisted with two soft tip cannulas was performed. One cannula pressed the cilioretinal artery branch directed toward the macula, distal to the location of the embolus, whereas the other cannula was used to gently swipe over the cilioretinal artery proximal to the occlusion. Anatomical and functional outcomes were evaluated by fundus examination, fluorescein angiography, Goldmann visual field, and best-corrected visual acuity (BCVA). It was possible to mobilize the embolus by mechanical displacement with 23-G soft-tip cannulas and disintegrate it, preventing the passage toward the branch directed to the macula. Restoration of retinal circulation was confirmed by fluorescein angiogram. The patient recovered his previous documented BCVA and visual field. The described technique can be considered as a new possibility for achieving a solution to cilioretinal artery occlusion or any other retinal artery occlusion.


Assuntos
Embolia , Oclusão da Artéria Retiniana , Oclusão da Veia Retiniana , Artérias Ciliares , Angiofluoresceinografia , Fundo de Olho , Humanos , Oclusão da Artéria Retiniana/diagnóstico
4.
Zhonghua Yan Ke Za Zhi ; 57(11): 850-856, 2021 Nov 11.
Artigo em Chinês | MEDLINE | ID: mdl-34743471

RESUMO

Objective: To investigate whether the wide field imaging system (WFIS), 25G optical fiber and intraoperative optical coherence tomography (iOCT) can perform real-time screening and diagnosing in patients with highly suspected fundus diseasesintraoperatively. Methods: A cross-sectional study was carried out. One hundred and eighty-three densely cataractous eyes of 183 patients with suspected fundus diseases were included in the Affiliated Hospital of Nantong University from July 2019 to June 2020. Lens phacoemulsification combined with intraocular lens implantation was performed in these eyes. Following the opaque lens was removed, the patients were divided into 4 groups according to fundus examination methods: WFIS SW-8000 group (49 eyes), 25G optical fiber group (40 eyes), iOCT group (36 eyes), and combination group of three examination methods (58 eyes). Optical coherence tomography and/or fundus fluorescence angiography were used to detect the fundus after surgery. The intraoperative and postoperative examination results were compared to verify the accuracy of intraoperative diagnosis in each group. Chi-square test was used for statistical analysis. Results: There were 79 males and 104 females in all patients, and the mean age was (69±10) years. Intraoperative examinations showed 82 eyes with fundus disease (positive rate was 44.81%), while postoperative examinations revealed 93 eyes with fundus disease (positive rate was 50.82%). In the WFIS SW-8000 group, fundus disease was found in 19 eyes intraoperatively and 26 eyes postoperatively (sensitive rate was 73.08%). In the 25G optical fiber group, fundus disease was found in 18 eyes intraoperatively and 20 eyes postoperatively (sensitive rate was 90.00%). In the iOCT group, fundus disease was observed in 20 eyes administratively and 22 eyes postoperatively (sensitive rate was 90.91%). In the combination group, fundus disease was observed in 25 eyes intraoperatively, which was consistent with the results of postoperative examinations (sensitive rate was 100.00%). There were statistically significant differences in the diagnostic sensitivity of fundus diseases among different methods (χ²=9.26; P<0.05). The diagnostic sensitivity of fundus diseases of the WFIS SW-8000 group was lower than that of the the combination group, the difference was statistically significant (χ²=7.80, P<0.01), and there was no significant difference between the other two groups (all P>0.05). Forty-nine eyes with fundus neovascular disease or severe macular edema requiring drug intervention were identified intraoperatively, and intravitreal anti-inflammatory and/or anti-vascular endothelial growth factor drugs were injected in 41 eyes. Conclusions: The WFIS, 25G optical fiber and iOCT can be used to examine the fundus and detect fundus disease intraoperatively, facilitating timely diagnosis and treatment of retinopathy in patients with dense cataract. The combined application of the three methods has the highest sensitivity. (Chin J Ophthalmol, 2021, 57: 850-856).


Assuntos
Catarata , Facoemulsificação , Idoso , Catarata/diagnóstico , Estudos Transversais , Feminino , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia de Coerência Óptica
5.
Comput Intell Neurosci ; 2021: 3812865, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34804140

RESUMO

Diabetic retinopathy (DR) is a diabetic complication affecting the eyes, which is the main cause of blindness in young and middle-aged people. In order to speed up the diagnosis of DR, a mass of deep learning methods have been used for the detection of this disease, but they failed to attain excellent results due to unbalanced training data, i.e., the lack of DR fundus images. To address the problem of data imbalance, this paper proposes a method dubbed retinal fundus images generative adversarial networks (RF-GANs), which is based on generative adversarial network, to synthesize retinal fundus images. RF-GANs is composed of two generation models, RF-GAN1 and RF-GAN2. Firstly, RF-GAN1 is employed to translate retinal fundus images from source domain (the domain of semantic segmentation datasets) to target domain (the domain of EyePACS dataset connected to Kaggle (EyePACS)). Then, we train the semantic segmentation models with the translated images, and employ the trained models to extract the structural and lesion masks (hereafter, we refer to it as Masks) of EyePACS. Finally, we employ RF-GAN2 to synthesize retinal fundus images using the Masks and DR grading labels. This paper verifies the effectiveness of the method: RF-GAN1 can narrow down the domain gap between different datasets to improve the performance of the segmentation models. RF-GAN2 can synthesize realistic retinal fundus images. Adopting the synthesized images for data augmentation, the accuracy and quadratic weighted kappa of the state-of-the-art DR grading model on the testing set of EyePACS increase by 1.53% and 1.70%, respectively.


Assuntos
Processamento de Imagem Assistida por Computador , Fundo de Olho , Humanos , Pessoa de Meia-Idade
6.
J Fr Ophtalmol ; 44(10): 1484-1490, 2021 Dec.
Artigo em Francês | MEDLINE | ID: mdl-34756744

RESUMO

Coronavirus disease (COVID-19) can result in many ocular manifestations. We report a rare case of bilateral central serous chorioretinopathy post-infection with COVID-19 in a 38-year-old woman who presented with bilateral blurred vision 1 month after infection with COVID-19. She reported fever, cough, and shortness of breath and was COVID-PCR positive. During her 10-day hospital stay, she received oxygen, antibiotics, heparin and corticosteroids intravenously and then orally. After her recovery from COVID-19, the patient developed progressive visual loss in both eyes: her corrected visual acuity was 3/10 in both eyes, the anterior segment was normal, and the vitreous was clear. Fundus examination, optical coherence tomography and fluorescein angiography showed bilateral serous retinal detachments. Her course was characterized by improvement in visual acuity and regression of the retinal detachments. Central serous chorioretinopathy can occur after COVID-19 infection due to the administration of corticosteroids; thus, ophthalmologic examination is essential to detect ocular involvement as early as possible.


Assuntos
COVID-19 , Coriorretinopatia Serosa Central , Adulto , Coriorretinopatia Serosa Central/diagnóstico , Coriorretinopatia Serosa Central/etiologia , Feminino , Angiofluoresceinografia , Fundo de Olho , Humanos , SARS-CoV-2 , Tomografia de Coerência Óptica
7.
Int J Mol Sci ; 22(19)2021 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-34639066

RESUMO

Fundus perimetry is a new technique for evaluating the light sense in the retina in a point-to-point manner. Light sense is fundamentally different from visual acuity, which measures the threshold for discriminating and perceiving two points or lines, called the minimum cognoscible. The quality of measurement of retinal sensitivity has dramatically increased in the last decade, and the use of fundus perimetry is now gaining popularity. The latest model of fundus perimetry, MP-3, can be used for a wide range of measurements and has an advanced eye tracking system. High background illumination enables accurate measurement of mesopic retail sensitivity. Recent investigations have shown that neuronal damage precedes vascular abnormalities in diabetic retinopathy. The loss of retinal function has also been reported prior to morphological changes in the retina. In this review, the importance of measuring retinal sensitivity to evaluate visual function in the early stages of diabetic retinopathy was discussed. The usefulness of retinal sensitivity as an outcome measure in clinical trials for treatment modalities is also presented. The importance of fundus perimetry is promising and should be considered by both diabetes researchers and clinical ophthalmologists.


Assuntos
Retinopatia Diabética/diagnóstico , Testes de Campo Visual/métodos , Tomada de Decisão Clínica , Neuropatias Diabéticas , Retinopatia Diabética/patologia , Retinopatia Diabética/fisiopatologia , Gerenciamento Clínico , Fundo de Olho , Humanos , Macula Lutea/patologia , Retina , Tomografia de Coerência Óptica , Acuidade Visual , Testes de Campo Visual/normas , Campos Visuais
8.
Int J Comput Assist Radiol Surg ; 16(12): 2177-2187, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34606059

RESUMO

PURPOSE: Diabetic retinopathy (DR) has become the leading cause of blindness worldwide. In clinical practice, the detection of DR often takes a lot of time and effort for ophthalmologist. It is necessary to develop an automatic assistant diagnosis method based on medical image analysis techniques. METHODS: Firstly, we design a feature enhanced attention module to capture focus lesions and regions. Secondly, we propose a stage sampling strategy to solve the problem of data imbalance on datasets and avoid the CNN ignoring the focus features of samples that account for small parts. Finally, we treat DR detection as a regression task to keep the gradual change characteristics of lesions and output the final classification results through the optimization method on the validation set. RESULTS: Extensive experiments are conducted on open-source datasets. Our methods achieve 0.851 quadratic weighted kappa which outperforms first place in the Kaggle DR detection competition based on the EyePACS dataset and get the accuracy of 0.914 in the referable/non-referable task and 0.913 in the normal/abnormal task based on the Messidor dataset. CONCLUSION: In this paper, we propose three novel automatic DR detection methods based on deep convolutional neural networks. The results illustrate that our methods can obtain comparable performance compared with previous methods and generate visualization pictures with potential lesions for doctors and patients.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Retinopatia Diabética/diagnóstico , Fundo de Olho , Humanos , Redes Neurais de Computação
9.
Zhonghua Yan Ke Za Zhi ; 57(10): 777-783, 2021 Oct 11.
Artigo em Chinês | MEDLINE | ID: mdl-34619949

RESUMO

Objective: To explore the incidence and age distribution of fundus abnormalities in pediatric patients aged 0-3 years in northwest China. Methods: A retrospective study of the clinical data of 8808 pediatric patients aged 0-3 years who underwent fundus examination with a wide-filed digital retinal imaging system and an indirect ophthalmoscope in our hospital from January 2008 to December 2019 were performed. There were 5092 males and 3716 females, with a median age of 1 month (range, 3 days to 3 years), a mean gestational age of 34.32 (SD 2.92) weeks (range, 24 to 42 weeks) and a mean birth weight of 2006.92 (SD 709.23) g (range, 490 to 5500 g), from Shaanxi Province (7415 cases, 84.18%), Gansu Province (770 cases, 8.74%), Ningxia Hui Autonomous Region (94 cases, 1.07%), Qinghai Province (53 cases, 0.60%), Xinjiang Uygur Autonomous Region (14 cases, 0.16%) and other neighboring areas (462 cases, 5.25%). The fundus condition of the enrolled pediatric patients was documented to calculate the annual detection rate. The joinpoint regression model was drawn to estimate the annual percent change and average annual percent change. The constituent ratios and age distribution of different types of fundus abnormalities were finally analyzed. Results: Fundus abnormalities were detected in 2 531 cases (28.74%). During the 12 years, the number of pediatric patients undergoing fundus examination each year in our center increased rapidly in the first 7 years, and then kept almost stable, while the number of fundus abnormality cases increased year by year. The positive detection rate showed an overall upward trend with an average annual percent change of +7.2%, and it was +30.09% from 2016 to 2019. Among all the pediatric patients with fundus abnormalities, there were 1 678 cases with developmental diseases (66.30%), 232 cases with hereditary diseases (9.16%), 140 cases with ocular tumor (5.53%), 64 cases with ophthalmic manifestations of systemic diseases (2.53%), 31 cases with ocular trauma (1.23%), 12 cases with infectious diseases or inflammation (0.48%) and 438 cases with other ocular abnormalities (17.31%). The top 5 abnormalities were retinopathy of prematurity (ROP; 1477 cases, 58.36%), gray patchy retinopathy (225 cases, 8.89%), retinal hemorrhage (157 cases, 6.20%), retinoblastoma (137 cases, 5.41%) and familial exudative vitreoretinopathy (77 cases, 3.04%). Fundus abnormalities varied with age. ROP, developmental diseases other than ROP, hereditary diseases, ocular trauma and infectious diseases were mostly detected in pediatric patients at 0-6 months old, while tumors were mostly detected after 1 year old. Conclusions: The detection rate of fundus abnormalities in the Department of Ophthalmology of Xijing Hospital of Air Force Medical University, a tertiary referral center in northwest China, increased notably year by year. The abnormalities were mainly developmental and hereditary lesions as well as of certain age distribution. They occurred with the highest frequency between birth and 6 months of age, in which ROP was in the ascendancy. Meanwhile, the detection rate of other developmental, hereditary and neoplastic disorders increased with age. Therefore, a comprehensive and objective understanding of the fundus disease in infants is essential. (Chin J Ophthalmol, 2021, 57: 777-783).


Assuntos
Doenças Retinianas , Criança , Pré-Escolar , China/epidemiologia , Feminino , Fundo de Olho , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Masculino , Doenças Retinianas/diagnóstico por imagem , Doenças Retinianas/epidemiologia , Estudos Retrospectivos
10.
Transl Vis Sci Technol ; 10(12): 9, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34614162

RESUMO

Purpose: To compare the effectiveness of the Optos P200dTx and Zeiss Clarus 500 fundus cameras in detecting diabetic retinopathy (DR) lesions. Methods: A cross-sectional study was conducted among 243 patients with clinically diagnosed diabetes mellitus who were referred for an eye examination from two tertiary eye care centers in Chennai, India. Patients underwent DR screening based on mydriatic fundal images acquired by both fundal cameras. Fundal images from the two separate devices for each eye were compared based on accurately identified pathological retinal lesions with respect to type and location. Results: When studying lesions of the central retina, they were better identified by the Zeiss Clarus compared with the Optos P200dTx, with six out of eight being statistically significant (P < 0.05). However, lesions of the mid-peripheral retina and peripheral retina were better identified by the Optos P200dTx than the Zeiss Clarus, with three out of eight lesions and five out of eight lesions being statistically significant (P < 0.05), respectively. Based on the color and size of lesions, the Optos P200dTx had a higher chance (59.6%) of missing white lesions than did the Zeiss Clarus (17%) (P < 0.0001). Consequently, small- and medium-sized lesions were missed more by the Optos P200dTx (30.72% and 32.63%, respectively) than the Zeiss Clarus (22.3% and 19.30%, respectively). Conclusions: The capability of detecting or missing a particular DR lesion among diabetics differed between the two cameras based on effective field of view, resolution, and the retinal zone being imaged. Translational Relevance: The choice of which ultra-widefield camera to be used for screening DR can be based on the greater prevalence of central versus peripheral retinal lesions noted in the patient population seen in a clinical practice.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Estudos Transversais , Retinopatia Diabética/diagnóstico , Fundo de Olho , Humanos , Índia , Retina/diagnóstico por imagem
11.
Invest Ophthalmol Vis Sci ; 62(13): 14, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34661607

RESUMO

Purpose: The purpose of this study was to investigate whether optical coherence tomography angiography (OCTA) metrics are related to retinal vessel geometry parameters in diabetic retinopathy (DR). Methods: In total, 119 eyes (119 patients) were included in this retrospective cross-sectional study. Retinal vessel geometry parameters were analyzed using semi-automated software. OCTA metrics were analyzed using automated manufacturer-provided algorithms. Associations between the severity of DR and retinal vessel geometry parameters and OCTA metrics were evaluated. Multivariable regression analyses were performed to evaluate associations between retinal vessel geometry parameters and OCTA metrics after adjusting for clinical characteristics and DR severity. Results: DR severity was negatively associated with the following: arteriole-venular ratio (P = 0.039), arteriolar network fractal dimension (FDa; P = 0.003), arteriolar junctional exponent deviation (P = 0.037), venular junctional exponent deviation (P = 0.036), vessel area density (VAD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP; P < 0.001, both), vessel length density (VLD) of the SCP and DCP (P < 0.001, both), and foveal avascular zone (FAZ) circularity (P < 0.001). DR severity was positively associated with the central retinal venular equivalent caliber (P = 0.005), arteriolar branching coefficient (BCa; P = 0.010), venular branching coefficient (P = 0.007), and FAZ size (P = 0.002). In multivariable regression analyses, the following retinal vessel geometry parameters and OCTA metrics were associated: FDa with VAD of the SCP (ß = 0.40, P < 0.001), FDa with VLD of the SCP (ß = 0.01, P < 0.001), and BCa with FAZ circularity (ß = -1.02, P = 0.001). Conclusions: In DR, changes in retinal arteriolar geometry parameters were significantly associated with OCTA metrics, which reflect DR pathophysiology.


Assuntos
Retinopatia Diabética/diagnóstico , Angiofluoresceinografia/métodos , Macula Lutea/irrigação sanguínea , Vasos Retinianos/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Estudos Transversais , Feminino , Fundo de Olho , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
12.
Comput Biol Med ; 138: 104928, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34662814

RESUMO

Fundus Image Segmentation (FIS) is an essential procedure for the automated diagnosis of ophthalmic diseases. Recently, deep fully convolutional networks have been widely used for FIS with state-of-the-art performance. The representative deep model is the U-Net, which follows an encoder-decoder architecture. I believe it is suboptimal for FIS because consecutive pooling operations in the encoder lead to low-resolution representation and loss of detailed spatial information, which is particularly important for the segmentation of tiny vessels and lesions. Motivated by this, a high-resolution hierarchical network (HHNet) is proposed to learn semantic-rich high-resolution representations and preserve spatial details simultaneously. Specifically, a High-resolution Feature Learning (HFL) module with increasing dilation rates was first designed to learn the high-level high-resolution representations. Then, the HHNet was constructed by incorporating three HFL modules and two feature aggregation modules. The HHNet runs in a coarse-to-fine manner, and fine segmentation maps are output at the last level. Extensive experiments were conducted on fundus lesion segmentation, vessel segmentation, and optic cup segmentation. The experimental results reveal that the proposed method shows highly competitive or even superior performance in terms of segmentation performance and computation cost, indicating its potential advantages in clinical application.


Assuntos
Aprendizado Profundo , Redes Neurais de Computação , Fundo de Olho , Processamento de Imagem Assistida por Computador , Vasos Retinianos/diagnóstico por imagem
14.
Invest Ophthalmol Vis Sci ; 62(13): 8, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34643661

RESUMO

Purpose: Cell-based therapy development for geographic atrophy (GA) in age-related macular degeneration (AMD) is hampered by the paucity of models of localized photoreceptor and retinal pigment epithelium (RPE) degeneration. We aimed to characterize the structural and functional deficits in a laser-induced nonhuman primate model, including an analysis of the choroid. Methods: Macular laser photocoagulation was applied in four macaques. Fundus photography, optical coherence tomography (OCT), dye angiography, and OCT-angiography were conducted over 4.5 months, with histological correlation. Longitudinal changes in spatially resolved macular dysfunction were measured using multifocal electroretinography (MFERG). Results: Lesion features, depending on laser settings, included photoreceptor layer degeneration, inner retinal sparing, skip lesions, RPE elevation, and neovascularization. The intralesional choroid was degenerated. The normalized mean MFERG amplitude within lesions was consistently lower than control regions (0.94 ± 0.35 vs. 1.10 ± 0.27, P = 0.032 at month 1, 0.67 ± 0.22 vs. 0.83 ± 0.15, P = 0.0002 at month 2, and 0.97 ± 0.31 vs. 1.20 ± 0.21, P < 0.0001 at month 3.5). The intertest variation of mean MFERG amplitudes in rings 1 to 5 ranged from 13.0% to 26.0% in normal eyes. Conclusions: Laser application in this model caused localized outer retinal, RPE, and choriocapillaris loss. Localized dysfunction was apparent by MFERG in the first month after lesion induction. Correlative structure-function testing may be useful for research on the functional effects of stem cell-based therapy for GA. MFERG amplitude data should be interpreted in the context of relatively high intertest variability of the rings that correspond to the central macula. Sustained choroidal insufficiency may limit long-term subretinal graft viability in this model.


Assuntos
Eletrorretinografia/métodos , Angiofluoresceinografia/métodos , Atrofia Geográfica/patologia , Segmento Externo das Células Fotorreceptoras da Retina/patologia , Tomografia de Coerência Óptica/métodos , Animais , Modelos Animais de Doenças , Fundo de Olho , Atrofia Geográfica/fisiopatologia , Macaca fascicularis , Epitélio Pigmentado da Retina/patologia , Epitélio Pigmentado da Retina/fisiopatologia , Acuidade Visual
15.
Sensors (Basel) ; 21(19)2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34640698

RESUMO

Optometrists, ophthalmologists, orthoptists, and other trained medical professionals use fundus photography to monitor the progression of certain eye conditions or diseases. Segmentation of the vessel tree is an essential process of retinal analysis. In this paper, an interactive blood vessel segmentation from retinal fundus image based on Canny edge detection is proposed. Semi-automated segmentation of specific vessels can be done by simply moving the cursor across a particular vessel. The pre-processing stage includes the green color channel extraction, applying Contrast Limited Adaptive Histogram Equalization (CLAHE), and retinal outline removal. After that, the edge detection techniques, which are based on the Canny algorithm, will be applied. The vessels will be selected interactively on the developed graphical user interface (GUI). The program will draw out the vessel edges. After that, those vessel edges will be segmented to bring focus on its details or detect the abnormal vessel. This proposed approach is useful because different edge detection parameter settings can be applied to the same image to highlight particular vessels for analysis or presentation.


Assuntos
Processamento de Imagem Assistida por Computador , Vasos Retinianos , Algoritmos , Técnicas de Diagnóstico Oftalmológico , Fundo de Olho , Vasos Retinianos/diagnóstico por imagem
16.
Comput Methods Programs Biomed ; 211: 106422, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34598080

RESUMO

BACKGROUND AND OBJECTIVE: Fundus fluorescein angiography (FFA) technique is widely used in the examination of retinal diseases. In analysis of FFA sequential images, accurate vessel segmentation is a prerequisite for quantification of vascular morphology. Current vessel segmentation methods concentrate mainly on color fundus images and they are limited in processing FFA sequential images with varying background and vessels. METHODS: We proposed a multi-path cascaded U-net (MCU-net) architecture for vessel segmentation in FFA sequential images, which is capable of integrating vessel features from different image modes to improve segmentation accuracy. Firstly, two modes of synthetic FFA images that enhance details of small vessels and large vessels are prepared, and are then used together with the raw FFA image as inputs of the MCU-net. By fusion of vessel features from the three modes of FFA images, a vascular probability map is generated as output of MCU-net. RESULTS: The proposed MCU-net was trained and tested on the public Duke dataset and our own dataset for FFA sequential images as well as on the DRIVE dataset for color fundus images. Results show that MCU-net outperforms current state-of-the-art methods in terms of F1-score, sensitivity and accuracy, and is able of reserving details such as thin vessels and vascular connections. It also shows good robustness in processing FFA images captured at different perfusion stages. CONCLUSIONS: The proposed method can segment vessels from FFA sequential images with high accuracy and shows good robustness to FFA images in different perfusion stages. This method has potential applications in quantitative analysis of vascular morphology in FFA sequential images.


Assuntos
Processamento de Imagem Assistida por Computador , Doenças Retinianas , Algoritmos , Angiofluoresceinografia , Fundo de Olho , Humanos , Vasos Retinianos/diagnóstico por imagem
17.
Invest Ophthalmol Vis Sci ; 62(13): 27, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34705024

RESUMO

Purpose: To identify the presence of choroidal microvascular dropout (MvD) in nonarteritic anterior ischemic optic neuropathy (NAION) eyes and to characterize the topographical distribution for the mechanistic interpretation of MvD development. Methods: We performed optical coherence tomography angiography on 47 open-angle glaucoma (OAG) and 19 NAION eyes with ß-zone peripapillary atrophy (ßPPA). We recorded the presence of MvD and compared between the peripapillary topographical measures of MvD, retinal nerve fiber layer (RNFL) defect, and ßPPA in angular width and location. Results: MvD was present in both diseases, marginally more frequently in NAION eyes (19/19, 100.0%) than in OAG eyes (38/47, 80.6%, P = 0.050), without a discernable difference in appearance. NAION eyes also showed wider MvD and RNFL defects compared to OAG eyes (both P < 0.001). In topographical measurements, the distribution of MvD showed a strong correspondence to superimposition areas of ßPPA and RNFL defects, more distinctly than to RNFL defects (all P < 0.001). The outline of superimposition area also remarkably resembled the MvD area. Conclusions: MvD was present in both the OAG and NAION groups. The ßPPA-RNFL defect superimposition area topographically and morphologically matched MvD. Further investigations are needed to elucidate the role of RNFL defects in the pathogenesis of MvD and the clinical significance.


Assuntos
Corioide/irrigação sanguínea , Angiofluoresceinografia/métodos , Glaucoma/diagnóstico , Microvasos/patologia , Neuropatia Óptica Isquêmica/diagnóstico , Vasos Retinianos/patologia , Tomografia de Coerência Óptica/métodos , Estudos Transversais , Feminino , Seguimentos , Fundo de Olho , Glaucoma/complicações , Glaucoma/fisiopatologia , Glaucoma de Ângulo Aberto , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Fibras Nervosas/patologia , Disco Óptico/patologia , Neuropatia Óptica Isquêmica/etiologia , Neuropatia Óptica Isquêmica/fisiopatologia , Células Ganglionares da Retina/patologia , Estudos Retrospectivos , Campos Visuais
18.
Invest Ophthalmol Vis Sci ; 62(13): 28, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34709347

RESUMO

Purpose: To assess the influence of lesion morphology and location on geographic atrophy (GA) growth rate. Methods: We manually delineated GA on color fundus photographs of 237 eyes in the Age-Related Eye Disease Study. We calculated local border expansion rate (BER) as the linear distance that a point on the GA border traveled over 1 year based on a Euclidean distance map. Eye-specific BER was defined as the mean local BER of all points on the GA border in an eye. The percentage area affected by GA was defined as the GA area divided by the total retinal area in the region. Results: GA enlarged 1.51 ± 1.96 mm2 in area and 0.13 ± 0.11 mm in distance over 1 year. The GA area growth rate (mm2/y) was associated with the baseline GA area (P < 0.001), perimeter (P < 0.001), lesion number (P < 0.001), and circularity index (P < 0.001); in contrast, eye-specific BER (mm/y) was not significantly associated with any of these factors. As the retinal eccentricity increased from 0 to 3.5 mm, the local BER increased from 0.10 to 0.24 mm/y (P < 0.001); in contrast, the percentage of area affected by GA decreased from 49.3% to 2.3%. Conclusions: Using distance-based measurements allows GA progression evaluation without significant confounding effects from baseline GA morphology. Local GA progression rates increased as a function of retinal eccentricity within the macula which is opposite of the trend for GA distribution, suggesting that GA initiation and enlargement may be mediated by different biological processes.


Assuntos
Angiofluoresceinografia/métodos , Atrofia Geográfica/diagnóstico , Epitélio Pigmentado da Retina/patologia , Tomografia de Coerência Óptica/métodos , Acuidade Visual , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Seguimentos , Fundo de Olho , Atrofia Geográfica/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
19.
Indian J Ophthalmol ; 69(11): 2951-2958, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34708729

RESUMO

The increased burden of diabetes in India has resulted in an increase in the complications of diabetes including sight-threatening diabetic retinopathy (DR). Visual impairment and blindness due to DR can be prevented by early detection and management of sight-threatening DR. Life-long evaluation by repetitive retinal screening of people with diabetes is an essential strategy as DR has an asymptomatic presentation. Fundus examination by trained ophthalmologists and fundus photography are established modes of screening. Various modes of opportunistic screening have been followed in India. Hospital-based screening (diabetes care/eye care) and community-based screening are the common modes. Tele-ophthalmology programs based on retinal imaging, remote interpretation, and grading of DR by trained graders/ophthalmologists have facilitated greater coverage of DR screening and enabled timely referral of those with sight-threatening DR. DR screening programs use nonmydriatic or mydriatic fundus cameras for retinal photography. Hand-held/smartphone-based fundus cameras that are portable, less expensive, and easy to use in remote places are gaining popularity. Good retinal image quality and accurate diagnosis play an important role in reducing unnecessary referrals. Recent advances like nonmydriatic ultrawide field fundus photography can be used for DR screening, though likely to be more expensive. The advent of artificial intelligence and deep learning has raised the possibility of automated detection of DR. Efforts to increase the awareness regarding DR is essential to ensure compliance to regular follow-up. Cost-effective sustainable models will ensure systematic nation-wide DR screening in the country.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Inteligência Artificial , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/epidemiologia , Fundo de Olho , Humanos , Índia/epidemiologia , Programas de Rastreamento , Fotografação
20.
Indian J Ophthalmol ; 69(11): 2968-2976, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34708731

RESUMO

Diabetic retinopathy (DR) is a leading cause of blindness among adults and the numbers are projected to rise. There have been dramatic advances in the field of retinal imaging since the first fundus image was captured by Jackman and Webster in 1886. The currently available imaging modalities in the management of DR include fundus photography, fluorescein angiography, autofluorescence imaging, optical coherence tomography, optical coherence tomography angiography, and near-infrared reflectance imaging. These images are obtained using traditional fundus cameras, widefield fundus cameras, handheld fundus cameras, or smartphone-based fundus cameras. Fluorescence lifetime ophthalmoscopy, adaptive optics, multispectral and hyperspectral imaging, and multicolor imaging are the evolving technologies which are being researched for their potential applications in DR. Telemedicine has gained popularity in recent years as remote screening of DR has been made possible. Retinal imaging technologies integrated with artificial intelligence/deep-learning algorithms will likely be the way forward in the screening and grading of DR. We provide an overview of the current and upcoming imaging modalities which are relevant to the management of DR.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Adulto , Inteligência Artificial , Retinopatia Diabética/diagnóstico por imagem , Angiofluoresceinografia , Fundo de Olho , Humanos , Fotografação , Retina/diagnóstico por imagem , Tomografia de Coerência Óptica
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