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
;
Macular Edema
;
diagnostic imaging
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Radiography
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Tomography, Optical Coherence
;
methods
3.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
;
methods
;
Humans
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Image Enhancement
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methods
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Retinal Vessels
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anatomy & histology
4.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
;
diagnostic imaging
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.Spectral domain optical coherence tomography of Vogt-Koyanagi-Harada disease: novel findings and new insights into the pathogenesis.
Chan ZHAO ; Mei-Fen ZHANG ; Fang-Tian DONG ; Xu-Qian WANG ; Xin WEN ; Rong-Ping DAI ; Wei-Hong YU ; Zhi-Qiao ZHANG ; Zhi-Kun YANG ; Fei GAO
Chinese Medical Sciences Journal 2012;27(1):29-34
OBJECTIVETo provide novel spectral domain optical coherence tomography (SD OCT) findings of Vogt-Koyanagi-Harada (VKH) disease as well as new insights into the pathogenesis of this disease.
METHODSDetailed SD OCT and fluorescein angiography (FA) findings of 18 consecutive VKH patients (11 women and 7 men) from December 2007 to April 2009 who were in acute uveitic stage at presentation were reviewed. All the patients had been followed up for at least 6 months with reevaluation(s) of SD OCT performed in 10 patients.
RESULTSIntraretinal cysts were found to be located in various layers of the outer retina. In addition to the photoreceptor layer, they could also be found between the outer plexiform layer and the outer nuclear layer, or spanning the external limiting membrane. On FA, intraretinal cysts could be hypofluorescent, normofluorescent, or hyperfluorescent. Some intraretinal cysts had a characteristic FA pattern, in which a small round hypofluorescent area was surrounded by a ring of hyperfluorescence (donut-shaped dye pooling). Subretinal fibrinoid deposit appeared in acute uveitic stage in two severe VKH patients and seemed to develop from subretinal exudates and evolved into typical subretinal fibrosis. Gradual transfiguration/migration and progressive proliferation/pigmentation of the subretinal fibrinoid deposit/subretinal fibrosis was observed in one patient.
CONCLUSIONSIntraretinal cysts could form in various layers of the outer retina and may result from extension of choroidal inflammation. Subretinal fibrosis may develop from subretinal exudates in VKH patients and may cause substantial visual impairment.
Adolescent ; Adult ; Cysts ; pathology ; Female ; Fibrosis ; Fluorescein Angiography ; Humans ; Male ; Middle Aged ; Retina ; pathology ; Tomography, Optical Coherence ; methods ; Uveomeningoencephalitic Syndrome ; etiology ; pathology
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.Therapeutic Effect of Steroids in Patients with Non-arteritic Anterior Ischemic Optic Neuropathy.
Jun Soo EUN ; Myung Won LEE ; Sung Eun KYUNG
Journal of the Korean Ophthalmological Society 2017;58(10):1176-1182
PURPOSE: To investigate the effect of steroid treatment (intravenous injection, oral) in patients with non-arteritic anterior ischemic optic neuropathy (NAION). METHODS: From January, 2005 to December, 2016, 41 patients who were diagnosed with NAION and observed for more than 6 months were included in this study. The treatment was decided based on patient's choice after explaining the advantages and disadvantages of steroid therapy. The patients were divided into three groups (intravenous steroid injection, oral steroid, no treatment). Initial visual acuity, final visual acuity, degree of visual field defect, fluorescein angiography, visual evoked potential and brain magnetic resonance imaging were analyzed by chart review. RESULTS: The chief complaints of the 41 NAION patients at the first visit were decreased visual acuity (n = 24), visual field defect (n = 10), no symptoms (n = 4), diplopia (n = 2), and floaters (n = 1). The distribution of the patients according to steroid administration method was 15 patients with intravenous steroid injection, 14 patients with oral steroid and 12 patients with no treatment. The improvement in visual acuity was greatest in intravenous steroid injection (87%), oral steroid (43%) and no treatment (33%) in that order. CONCLUSIONS: In a retrospective comparison of treatment effects after explaining the advantages and disadvantages of steroid therapy in patients with NAION, the intravenous steroid injection group showed 87% improvement in visual acuity and an odds ratio of 5.5 (95% confidence interval [CI] 1.05–28.88, p-value 0.04), while the oral steroid group showed 43% improvement and an odds ratio of 1.5 (95% CI 0.30–7.43, p-value 0.62). The steroid treatment group showed better visual acuity improvement than the no treatment group, and the intravenous steroid injection group showed 5.5 times greater improvement in visual acuity compared to the no treatment group.
Brain
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Diplopia
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Evoked Potentials, Visual
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Fluorescein Angiography
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Humans
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Magnetic Resonance Imaging
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Methods
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Odds Ratio
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Optic Neuropathy, Ischemic*
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Retrospective Studies
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Steroids*
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Visual Acuity
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Visual Fields