1.Measurement of the irregular retinal lesion area based on the back propagation neural network method.
Yongxin GUO ; Weimin BI ; Guangyu ZHANG ; Chen DI ; Dong CUI ; Lei HU ; Qing JIAO
Chinese Journal of Medical Instrumentation 2010;34(6):411-417
In this study, the automatic segmentation of the irregular lesion region in the image of fundus fluorescence angiography was actualized by means of the modified Back Propagation (BP) neural network method. Combining the transfer scaling coefficient between pixel of the image and the actual size, the area of the irregular lesion region was measured. The results may provide valuable data for the clinical diagnosis, treatment and prognostic evaluation.
Algorithms
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Fluorescein Angiography
;
methods
;
Nerve Net
;
Retinal Diseases
;
diagnosis
;
pathology
2.Application of improved PCNN algorithm in retinal macular edema segmentation.
Zhinan XIE ; Min GU ; Yixiao WU ; Dong ZHENG
Chinese Journal of Medical Instrumentation 2012;36(6):411-414
In order to extract the outlines of macular edema from OCT images of macular, and estimate the volume of edema, we have to accurately segment the macular edema region. In this paper, an improved PCNN algorithm was proposed to conduct the above process. Combined with the adaptive base threshold, and the simplified neural network parameters, a binary image of macular edema was produced. According to the principle of maximum image entropy, the optimal number of iterations was determined as 8, which was evaluated by its misclassification rate. Simulation showed that the proposed algorithm could extract the macular edema region rapidly and accurately, providing the basis for further OCT image analysis.
Algorithms
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Fluorescein Angiography
;
methods
;
Humans
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Macular Edema
;
diagnostic imaging
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Radiography
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Tomography, Optical Coherence
;
methods
3.Based on blood vessel edge feature fundus fluorescein angiography image splicing.
Dong CUI ; Minmin LIU ; Yongxin GUO ; Qing JIAO
Chinese Journal of Medical Instrumentation 2011;35(3):181-184
According to fundus fluorescein angiography images characteristics, this paper proposes a feature based image mosaic vessel edge method. First, detect edge of blood vessels by carrying on the pretreatment to the fundus fluorescein angiography image in the foundation, wavelet edge detection algorithm. Then, the matching method based on chain code feature is described. Finally, a local area based on gray level information of the image fusion method is applied to angiographic image series. Data processing results show that the method can generate an ideal mosaic effect.
Fluorescein Angiography
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methods
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Humans
;
Image Processing, Computer-Assisted
;
methods
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Radiography
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Retinal Vessels
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diagnostic imaging
4.The preprocessing of subtraction and the enhancement for biomedical image of retinal blood vessels.
Tusheng LIN ; Minghui DU ; Jintang XU
Journal of Biomedical Engineering 2003;20(1):56-59
Image segmentation is still a difficult problem since its effect would vary with the subjects processed. An approach of subtracting background from the entire image of retinal blood vessels presented in this paper. The background subtraction is based on the real image itself taken photographically and is not dependent on the prior knowledge of system for recording image, the approach achieves the grayscale enhancement of retinal blood vessels in preprocessing and provides a quality image for the next process of binarization. This experiment in the preprocessing of subtraction shows good enhancement effect.
Algorithms
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Artifacts
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Fluorescein Angiography
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methods
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Humans
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Image Enhancement
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methods
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Retinal Vessels
;
anatomy & histology
5.Comparative study on retinal microvasculature changes between acute and chronic central serous chorioretinopathy.
Xiaogang WANG ; Jie ZHANG ; Renhe YU ; Liang ZHOU
Journal of Central South University(Medical Sciences) 2022;47(8):1075-1081
OBJECTIVES:
Central serous chorioretinopathy (CSC) is generally a common fundus disease in young and middle-aged Asian men. Acute and chronic CSC can lead to different degrees of injury to the retinal blood flow. This study aims to observe and compare the blood flow density in different retinal capillary layers in patients with acute and chronic CSC using optical coherence tomography angiography (OCTA) technology.
METHODS:
Twelve patients with acute CSC and 8 patients with chronic CSC including 12 eyes with acute CSC (acute CSC eye group), 11 eyes with chronic CSC (chronic CSC eye group), and 17 normal eyes (normal eye group) were enrolled in this study. All patients underwent 3 mm×3 mm, 6 mm×6 mm macular OCTA scanning. The retinal microvascu-lature was divided into superficial vascular complexes (SVC), intermediate capillary plexuses (ICP), and deep capillary plexuses (DCP) using the projection resolved-OCTA algorithm. Inner retina includes SVC, ICP, and DCP. The vessel density in each retinal layer and the inner retina were calculated and compared.
RESULTS:
Macular OCTA scanning of 3 mm×3 mm showed that there was no significant difference in blood flow density of SVC and ICP among the 3 groups (both P>0.05); blood flow density of DCP and inner retina in the chronic CSC eye group was significantly lower than that in the acute CSC eye group and the normal eye group (all P<0.05); there was no significant difference in retinal blood flow density of different layer between the acute CSC eye group and the normal eye group (all P>0.05). Macular OCTA scanning of 6 mm×6 mm showed that inner retinal blood flow density of the chronic CSC eye group was significantly lower than that of the acute CSC eye group and the normal eye group (both P<0.05); there was no significant difference in blood flow density of SVC among the 3 groups (P>0.05).
CONCLUSIONS
The vessel density of DCP and inner retina in the eyes with chronic CSC are significantly reduced, which may result in impaired visual function. Therefore, we recommend that patients with acute CSC should be properly treated to avoid progressing into chronic CSC.
Central Serous Chorioretinopathy/diagnostic imaging*
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Fluorescein Angiography/methods*
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Humans
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Male
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Microvessels/diagnostic imaging*
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Middle Aged
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Retina
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Tomography, Optical Coherence/methods*
6.Ultrawide-field Fluorescein Angiography for Evaluation of Diabetic Retinopathy.
Mingui KONG ; Mee Yon LEE ; Don Il HAM
Korean Journal of Ophthalmology 2012;26(6):428-431
PURPOSE: To investigate the advantages of ultrawide-field fluorescein angiography (FA) over the standard fundus examination in the evaluation of diabetic retinopathy (DR). METHODS: Ultrawide-field FAs were obtained in 118 eyes of 59 diabetic patients; 11 eyes with no DR, 71 eyes with nonproliferative diabetic retinopathy (NPDR), and 36 eyes with proliferative diabetic retinopathy (PDR), diagnosed by the standard method. The presence of peripheral abnormal lesions beyond the standard seven fields was examined. RESULTS: Ultrawide-field FA images demonstrated peripheral microaneurysms in six (54.5%) of 11 eyes with no DR and all eyes with moderate to severe NPDR and PDR. Peripheral retinal neovascularizations were detected in three (4.2%) of 71 eyes with NPDR and in 13 (36.1%) of 36 eyes with PDR. Peripheral vascular nonperfusion and vascular leakage were found in two-thirds of eyes with severe NPDR and PDR. CONCLUSIONS: Ultrawide-field FA demonstrates peripheral lesions beyond standard fields, which can allow early detection and a close evaluation of DR.
Aged
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Diabetic Retinopathy/*diagnosis
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Diagnosis, Differential
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Female
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Fluorescein Angiography/*methods
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Fundus Oculi
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Humans
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Male
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Middle Aged
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Reproducibility of Results
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Retina/*pathology
7.Association between Microperimetric Parameters and Optical Coherent Tomographic Findings in Various Macular Diseases.
Dong Yoon KIM ; Hyun Seung YANG ; Yoon Jun KOOK ; Joo Yong LEE
Korean Journal of Ophthalmology 2015;29(2):92-101
PURPOSE: To analyze the correlation between microperimetric parameters and optical coherent tomographic findings in the eyes of patients with macular diseases. METHODS: A total of 64 eyes were included in this retrospective cross-sectional study. Differences in the macular integrity index and microperimetric parameters were analyzed according to types of outer retinal band defects. Correlations between average threshold values and retinal thickness in the corresponding areas were analyzed. Finally, microperimetric parameters were compared between inner and outer retinal lesions. RESULTS: Measures of best-corrected visual acuity, macular integrity index, and average threshold values were significantly worse in eyes with defects in the ellipsoid portion of the photoreceptor inner segment (ISe), the cone outer segment tip (COST), and the external limiting membrane (ELM) than in eyes without ISe, COST, and ELM defects. Also, visual functionality is more significantly impacted by ELM defects than by other hyper-reflective band defects. There was a significant negative correlation between retinal thickness and the average threshold of the corresponding area in the Early Treatment Diabetic Retinopathy Study grid. Microperimetric parameters in the eyes of patients with inner retinal lesions were better than in the eyes of patients with outer retinal lesions. CONCLUSIONS: The macular integrity index may be a useful factor for reflecting the functional aspects of macular diseases. Specifically, ELM, ISe, and COST defects are significantly associated with poor retinal sensitivity and macular integrity index values that suggest abnormalities. Among eyes with these particular defects, the visual functionality of patients is most sensitively impacted by ELM defects. This finding suggests that microperimetric parameters are sensitive and useful for evaluating functional abnormalities in the eyes of patients with macular disease, particularly in patients with outer retinal pathology.
Cross-Sectional Studies
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Female
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Fluorescein Angiography
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Fundus Oculi
;
Humans
;
Macula Lutea/*pathology
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Macular Edema/*diagnosis
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Male
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Middle Aged
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Retrospective Studies
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Tomography, Optical Coherence/*methods
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Visual Field Tests/*methods
8.Surgical Management of Bilateral Exudative Retinal Detachment associated with Central Serous Chorioretinopathy.
Ji Eun KANG ; Hyun Jin KIM ; Hee Don BOO ; Ha Kyoung KIM ; Jeong Hee LEE
Korean Journal of Ophthalmology 2006;20(2):131-138
PURPOSE: To report a case of bilateral bullous exudative retinal detachment in central serous chorioretinopathy (CSC) which was attached by vitrectomy and internal drainage of the subretinal fluid. METHODS: A 47-year-old man affected by bilateral atypical CSC with a bullous retinal detachment with subretinal exudate. A fluorescein angiogram (FAG) showed multiple points of leakage and staining of subretinal fibrosis. A tentative diagnosis of Vogt-Koyanagi-Harada (VKH) syndrome was made and the patient was treated with systemic corticosteroids and immunosuppressive agents. However, the subretinal fluid was not absorbed. He was then treated with vitrectomy and internal drainage of subretinal fluid. RESULTS: The retina was attached successfully in both eyes. Visual acuity improved to 20/50 in his left eye but did not improve in the right eye due to subretinal fibrotic scarring and atropic changes on the macula. CONCLUSIONS: Our case suggests that the surgical management of bullous exudative retinal detachment is safe and necessary.
*Vitrectomy
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Retinal Detachment/etiology/pathology/*surgery
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Middle Aged
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Male
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Humans
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Fundus Oculi
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Follow-Up Studies
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Fluorescein Angiography
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Exudates and Transudates
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Drainage/*methods
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Diagnosis, Differential
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Choroid Diseases/*complications/diagnosis
9.A Case of Diode Laser Photocoagulation in the Treatment of Choroidal Metastasis of Breast Carcinoma.
Sang Joon LEE ; Soo Young KIM ; Shin Dong KIM
Korean Journal of Ophthalmology 2008;22(3):187-189
To report a single case of improvement on choroidal metastasis of breast cancer after laser photocoagulation. A 52-year-old female patient who complained of visual disturbance of the right eye with multiple states of metastasis of breast carcinoma. On initial examination, the right best-corrected visual acuity was 0.63. Right fundoscopy revealed an elevated mass-like lesion temporal to the macule with serous retinal detachment. The mass had a 3.5-disc diameter. A right fluorescein angiogram revealed hypofluorescence during the prearterial and arteriovenous phase and hyperfluorescence during the venous phase. The venous phase showed almost total masking of background choroidal fluorescence at the elevated lesion because of leakage and neovascularization. The patient was treated 4 times by diode laser photocoagulation in addition to chemotherapy. Fifty days after the diode laser treatments, the funduscopy examination and fluorescein angiogram revealed that the serous retinal detachment had been absorbed, the choroid had become flat, the lesion had been reduced in size and hyperfluorescence. The right best-corrected visual acuity was improved to 0.8. Laser photocoagulation appears not to cause any problems for the patient and may be an efficient treatment for patients with choroidal breast carcinoma.
Breast Neoplasms/pathology/*surgery
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Carcinoma, Ductal, Breast/secondary/*surgery
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Choroid Neoplasms/secondary/*surgery
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Female
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Fluorescein Angiography
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Humans
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Laser Coagulation/*methods
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Lasers, Semiconductor/*therapeutic use
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Middle Aged
;
Visual Acuity
10.Simplified Correction of Ischemic Index in Diabetic Retinopathy Evaluated by Ultra-widefield Fluorescein Angiography.
Jeong Hee KIM ; Hyeong Gi JUNG ; Hye Jin CHUNG ; Kyungmin LEE ; Joonhong SOHN
Korean Journal of Ophthalmology 2015;29(3):168-172
PURPOSE: To develop a novel, simplified method for correcting the ischemic index of nonperfused areas in diabetic retinopathy (DR). METHODS: We performed a retrospective review of 103 eyes with naive DR that underwent ultra-widefield angiography (UWFA) over a year. UWFAs were graded according to the quantity of retinal non-perfusion, and uncorrected ischemic index (UII) and corrected ischemic index (CII) were calculated using a simplified, novel method. RESULTS: The average differences between UII and CII in the non-proliferative DR group and the proliferative DR group were 0.7 +/- 0.9% in the <25% CII group, 3.0 +/- 0.9% in the 25% to 49.9% CII group, and 3.6 +/- 0.6% in the >50% CII group, respectively. A CII >25% was critical for determining DR progression (p < 0.001). CONCLUSIONS: Distortion created by UWFA needs to be corrected because the difference between UII and CII in DR increases with the ischemic index.
Adult
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Aged
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Aged, 80 and over
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Diabetic Retinopathy/*diagnosis/pathology
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Female
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Fluorescein Angiography/*methods
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Humans
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Ischemia/pathology
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Male
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Middle Aged
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Retinal Vein/pathology
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Retrospective Studies
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Sensitivity and Specificity