1. <div id="8sgz1"><ol id="8sgz1"></ol></div>

        <em id="8sgz1"><label id="8sgz1"></label></em>
      2. <em id="8sgz1"><label id="8sgz1"></label></em>
        <em id="8sgz1"></em>
        <div id="8sgz1"><ol id="8sgz1"><mark id="8sgz1"></mark></ol></div>

        <button id="8sgz1"></button>
        west china medical publishers
        Keyword
        • Title
        • Author
        • Keyword
        • Abstract
        Advance search
        Advance search

        Search

        find Keyword "optical coherence tomography" 23 results
        • Correlation of aqueous humor cytokine profiles with disorganization of retinal inner layers and postoperative visual acuity in idiopathic epiretinal membrane

          ObjectiveTo observe and analyze the correlations between aqueous humor cytokine concentrations and disorganization of retinal inner layers (DRIL), as well as postoperative visual acuity, in patients with idiopathic epiretinal membrane (iERM). MethodsA prospective clinical study. From November 2022 to October 2024, 40 eyes of 40 patients diagnosed with iERM at Ophthalmology Center of Zhejiang Provincial People's Hospital (Affiliated People's Hospital) underwent cataract surgery alone or combined with pars plana vitrectomy (iERM group) were enrolled; 19 eyes of 19 patients undergoing cataract surgery alone during the same period served as the control group. All eyes underwent best-corrected visual acuity (BCVA) testing and swept-source optical coherence tomography (SS-OCT). BCVA was assessed using a logarithmic visual acuity chart and converted to the logarithm of the minimum angle of resolution (logMAR) for statistical analysis. Central macular thickness (CMT) was measured using SS-OCT. The iERM group was further subdivided into DRIL-positive and DRIL-negative subgroups (21 eyes and 19 eyes, respectively), based on the presence or absence of DRIL. Aqueous humor samples were collected preoperatively from eyes in both the iERM and control groups. Concentrations of transforming growth factor (TGF)-β1, TGF-β2, TGF-β3, platelet-derived growth factor (PDGF)-AB, hepatocyte growth factor, fibroblast growth factor, vascular endothelial growth factor-A (VEGF-A), placental growth factor (PLGF), glial cell line-derived neurotrophic factor (GDNF), intercellular adhesion molecule-1 (ICAM-1), angiopoietin (Ang)-1, Ang-2, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured. Follow-up examinations using the same equipment and methods were performed at 1 month postoperatively. Aqueous cytokine levels were compared between the iERM group, control group, DRIL-positive subgroup, and DRIL-negative subgroup. Correlations between aqueous cytokine levels in the iERM group and BCVA or CMT were also analyzed. Intergroup comparisons utilized the Mann-Whitney U test; correlations between variables were assessed using Spearman's rank correlation analysis. ResultsCompared to the control group, the iERM group exhibited significantly higher aqueous concentrations of TGF-β1, TGF-β3, PDGF-AB, PLGF, GDNF, ICAM-1, Ang-1, and TNF-α (P<0.05). Compared to the DRIL-negative subgroup, the DRIL-positive subgroup showed significantly elevated aqueous concentrations of TGF-β3, PDGF-AB, PLGF, GDNF, ICAM-1, Ang-1, Ang-2, TNF-α, and IL-6 (P<0.05). Significant differences were observed in logMAR BCVA (P=0.028) and CMT (P<0.001) within the iERM group between preoperative and 1-month postoperative measurements. LogMAR BCVA differed significantly between the DRIL-positive and DRIL-negative subgroups (P=0.048). Correlation analysis revealed that baseline aqueous levels of VEGF-A and IL-6 in eyes with DRIL were positively correlated with postoperative BCVA (r=0.324, 0.452; P=0.042, 0.003). No significant correlation was found between CMT and any cytokine (P>0.05). ConclusionsAqueous humor cytokines are closely associated with DRIL in iERM patients. IL-6 and VEGF-A may serve as potential predictive biomarkers for early postoperative visual recovery.

          Release date:2025-08-15 01:04 Export PDF Favorites Scan
        • Numerical Simulation of Heat Transfer in the Human Anterior Chamber at Different Corneal Temperatures

          A three-dimensional (3D) model of human anterior chamber is reconstructed to explore the effect of different corneal temperatures on the heat transfer in the chamber. Based on the optical coherence tomography imaging of the volunteers with normal anterior chamber, a 3D anterior chamber model was reconstructed by the method of UG parametric design. Numerical simulation of heat transfer and aqueous humor flow in the whole anterior chamber were analyzed by the finite volume methods at different corneal temperatures. The results showed that different corneal temperatures had obvious influence on the temperature distribution and the aqueous flow in the anterior chamber. The temperature distribution is linear and axial symmetrical around the pupillary axis. As the temperature difference increases, the symmetry becomes poorer. Aqueous floated along the warm side and sank along the cool side which forms a vortexing flow. Its velocity increased with the addition of temperature difference. Heat fluxes of cornea, lens andiris were mainly affected by the aqueous velocity. The higher the velocity, the bigger more absolute value of the above-mentioned heat fluxes became. It is practicable to perform the numerical simulation of anterior chamber by the optical coherence tomography imaging. The results are useful for studying the important effect of corneal temperature on the heat transfer and aqueous humor dynamics in the anterior chamber.

          Release date: Export PDF Favorites Scan
        • Alterations of choroidal vasculature after submacular fluid absorption in central serous chorioretinopathy using ultra-widefield swept-source optical coherence tomography angiography

          ObjectiveTo analyze the associations between the choroidal vasculature and submacular fluid (SMF) in central serous chorioretinopathy (CSC). MethodsA retrospective study. A total of 29 CSC patients (31 eyes) with complete records who visited the Department of Ophthalmology in Peking University People's Hospital from August 1, 2021 to March 1, 2023 were included in this study. The patients were divided into complete absorption and incomplete absorption groups according to the status of SMF in the last visit. All the patients underwent ultra-widefield swept-source optical coherence tomography angiography (UWF SS-OCTA) with a scanning range of 24 mm × 20 mm. The UWF SS-OCTA images were automatically analyzed in 9 regions (superotemporal, superior, superonasal, temporal, central, nasal, inferotemporal, inferior, and inferonasal). Alterations of choroidal vasculature in the nine subfields after SMF absorption were described, including choroidal thickness (CT), flow density of choriocapillaris layer, vessel density of large choroidal vessel layer, three-dimensional choroidal vascularity index (CVI), the mean choroidal vessel volume (mCVV), and the mean choroidal stroma volume (mCSV). The relevant factors affecting the complete absorption of SMF were additionally evaluated. ResultsAt baseline, CT (Z=2.859, P=0.004), mCVV (t=2.514, P=0.018), and mCSV (Z=2.958, P=0.003) in the superotemporal region of the affected eyes in the incomplete absorption group were significantly higher than those in the complete absorption group. Compared with baseline, at the last visit, the proportion of asymmetric vortex veins in the complete absorption group was significantly decreased (χ2=6.000, P=0.014), CVI in the superotemporal, superonasal, temporal, central, nasal, inferotemporal, and inferonasal regions (t=-4.125, t=-3.247, Z=-3.213, t=-2.994, t=-3.417, t=-3.733, t=-3.795; P=0.001, 0.006, 0.001, 0.010, 0.005, 0.003, 0.002), the mCVV of 9 regions (t=-2.959, t=-2.537, t=-2.235, t=-3.260, t=-3.022, t=-2.796, t=-2.747, Z=-2.107, t=-2.935; P=0.011, 0.025, 0.044, 0.006, 0.010, 0.015, 0.017, 0.035, 0.012) were significantly decreased. Compared to the complete absorption group, the choroidal blood flow changes in the non-complete absorption group were more limited, and CT in the upper region increased significantly at the last follow-up (t=2.272, P=0.037). Multivariate logistic regression analysis revealed that baseline CT in the superotemporal region may be an independent risk factor affecting the complete absorption of SMF (odds ratio=0.981, 95% confidential interval 0.965-0.997, P=0.021). ConclusionsIn the process of SMF absorption in CSC, significant reductions of choroidal blood flow were found in the large choroidal vessel layer, and there may be a locally compensatory increase in CT. In addition, baseline CT in superotemporal region is an independent risk factor affecting SMF absorption.

          Release date:2023-05-18 10:05 Export PDF Favorites Scan
        • Coronary vessel intimal sequence extraction based on prior boundary constraints in optical coherence tomography image

          Optical coherence tomography (OCT) is a new technique applied in cardiovascular system. It can detect vessel intimal, small structure of plaque surface and discover small lesions with its high axial resolution and quantification character. Especially with the application of OCT in characterization of coronary atherosclerotic plaque, diagnosis and treatment strategy making, optimizing percutaneous coronary intervention therapy and assessment after stent planting make the OCT become an efficient tool for cardiovascular disease diagnosis and treatment. This paper presents a novel coronary vessel intimal sequence extraction method based on prior boundary constraints in OCT image. On the basis of conventional Chan-Vese model, we modified the evolutionary weight function to control the evolutionary rate of boundary by adding local information of boundary curve. At the same time, we added the gradient energy term and intimal boundary constraint term based on priori boundary condition to further control the evolutionary of boundary curve. At last, coronary vessel intimal is extracted in a sequence way. The comparison with vessel intimal, manual segmented by clinical scientists (golden standard), indicates that our coronary vessel intimal extraction method is robust to intimal boundary blur, distortion, guide wire shadow and plaque disturbs. The results of this study can be applied to clinical aid diagnosis and precise diagnosis and treatment.

          Release date:2019-02-18 02:31 Export PDF Favorites Scan
        • Fundus imaging features of glucocorticoid-related central serous chorioretinopathy

          ObjectiveTo compare and observe the fundus imaging characteristics of eyes with glucocorticoid-related central serous chorioretinopathy (CSC). MethodsA retrospective clinical study. A total of 149 CSC patients with 166 eyes diagnosed at Department of Ophthalmology of The First Affiliated Hospital of Zhengzhou University from March 2021 to October 2024 were included in the study. The duration of the disease from the appearance of symptoms to treatment was less than 3 months. All affected eyes underwent best-corrected visual acuity (BCVA), fundus color photography, swept-source optical coherence tomography (SS-OCT), and fundus fluorescein angiography (FFA) examinations. BCVA was tested using an international standard vision chart and converted into logarithm of the minimum angle of resolution (logMAR) visual acuity for statistical analysis. The SS-OCT instrument measured subfoveal choroidal thickness (SFCT), central macular thickness (CMT), choroidal vascular volume (CVV), and the width and height of flat irregular pigment epithelial detachment (FIPED). FIPED, subretinal fibrin, and choroidal layer strong reflective spots were identified from SS-OCTA B-scan images; multiple leakages (leak points >3) were identified from FFA images. Based on the presence or absence of a clear history of glucocorticoid administration before the onset, patients were divided into glucocorticoid-related and non-glucocorticoid-related groups, comprising 41 patients with 53 eyes and 108 patients with 113 eyes, respectively. Clinical and fundus imaging characteristics of the two groups were compared. The comparison of quantitative data between the two groups was performed using independent samples t test or non-parametric independent samples Wilcoxon test; the comparison of qualitative data was performed using χ2 test. ResultsCompared with the non-glucocorticoid-related group, the glucocorticoid-related group had a smaller male-to-female ratio and a higher bilateral incidence, and the differences were statistically significant (χ2=4.925, 17.849; P<0.05). The logMAR BCVA for the glucocorticoid-related and non-glucocorticoid-related groups were 0.45±0.33 and 0.21±0.21, respectively; SFCT were (644.43±131.91) and (507.26±121.79) μm; CMT were (389.51±233.45) and (362.59±140.85) μm; CVV were (4.44±1.07) and (3.67±0.82) mm3; FIPED incidence were 58.49% (31/58) and 20.35% (23/113), respectively; FIPED width and height were (1 122.01±533.98) and (742.90±388.79) μm, and (99.13±92.17) and (33.01±15.99) μm; subretinal fibrin were observed in 24 (45.28%, 24/53) and 15 (13.27%, 15/113) eyes; choroidal strong reflections were found in 38 (71.70%, 38/53) and 45 (39.82%, 45/113) eyes; multiple leak points were identified in 35 (66.03%, 35/53) and 40 (35.40%, 40/113) eyes, respectively. Compared with the non-glucocorticoid-related group, the glucocorticoid-related group had worse BCVA (Z=?4.984), thicker SFCT (t=6.586), larger CVV (t=5.160), higher incidence of FIPED (χ2=23.908), and greater width and height of FIPED (t=2.895, Z=?3.703). The glucocorticoid-related group also had a significantly increased incidence of subretinal fibrin, choroidal strong reflections, and multiple leak points, with all differences being statistically significant (χ2=20.565, 14.663, 13.675; P<0.05); however, the comparison of CMT showed no statistically significant difference (Z=?0.651, P>0.05). ConclusionCompared with non-glucocorticoid-related CSC, glucocorticoid-related CSC patients have poorer vision, are more likely to affect both eyes, show no gender bias; choroidal vascular dilation is more significant, and damage to the outer retina and retinal pigment epithelium is more severe.

          Release date:2025-05-14 02:04 Export PDF Favorites Scan
        • Automatic multi-region segmentation of intracoronary optical coherence tomography images based on neutrosophic theory

          Optical coherence tomography (OCT) has become a key technique in the diagnosis of coronary artery stenosis, which can identify plaques and vulnerable plaques in the image. Therefore, this technique is of great significance for the diagnosis of coronary heart disease. However, there is still a lack of automatic, multi-region, high-precision segmentation algorithms for coronary OCT images in the current research field. Therefore, this paper proposes a multi-zone, fully automated segmentation algorithm for coronary OCT images based on neutrosophic theory, which achieves high-precision segmentation of fibrous plaques and lipid regions. In this paper, the method of transforming OCT images into T in the area of neutrosophics is redefined based on the membership function, and the segmentation accuracy of fiber plaques is improved. For the segmentation of lipid regions, the algorithm adds homomorphic filter enhancement images, and uses OCT to transform OCT images into I in the field of neutrosophics, and further uses morphological methods to achieve high-precision segmentation. In this paper, 40 OCT images from 9 patients with typical plaques were analyzed and compared with the results of manual segmentation by doctors. Experiments show that the proposed algorithm avoids the over-segmentation and under-segmentation problems of the traditional neutrosophic theory method, and accurately segment the patch area. Therefore, the work of this paper can effectively improve the accuracy of segmentation of plaque for doctors, and assist clinicians in the diagnosis and treatment of coronary heart disease.

          Release date:2019-02-18 03:16 Export PDF Favorites Scan
        • Association between vortex vein dilatation patterns and choroidal thickness changes in patients with central serous chorioretinopathy

          ObjectiveTo observe the changes of chorioidal thickness (ChT) in patients with central serous chorioretinopathy (CSC) in different mode of vortic venous dilation. MethodsA prospective cross-sectional observational study. A total of 80 patients with 89 eyes (CSC group) diagnosed in Department of Ophthalmology, General Hospital of Central Theater Command from April to October 2023 were included in the study. Among them, 64 males had 71 eyes and 17 females had 18 eyes. A total of 15 healthy volunteers matched in age and sex were selected as the control group. Among them, 14 men had 26 eyes and one woman had two eyes. The macular region was examined by ultra-wide-angle scanning frequency source optical coherence tomography (OCTA) with BM400K BMizar made by TowardPi (Beijing) Medical Technology Co., LTD. Scanning rate 1 536 A scanning×1 280 B scanning, scanning range 24 mm×20 mm. The accompanying software delineated nine subfields (superotemporal, upper, superonasal, temporal, central, nasal, inferotemporal, lower, inferonasal regions) to record ChT. En-face OCTA mode was utilized to observe the anatomy and functional anastomosis of the vortex veins above and below the choroidal blood layer. Eyes in the CSC group were further categorized into upper-dominant, symmetrical, and lower-dominant groups based on the difference in vortex vein expansion shown in the choroidal layer of the en-face image, with 36, 35, and 18 eyes respectively. Statistical analysis included the use of independent samples t-test or Mann-Whitney test for comparison between two groups, one-way analysis of variance or Kruskal-Wallis H test for comparison between multiple groups, and the χ test or Fisher test for categorical variables. ResultsCompared with the control group, ChT in the CSC group was thickened in the foveal area and different areas of the macula, with the greatest difference in the fovea, and the differences were statistically significant (t=3.345, 5.018, 2.902, 4.667, 7.276, 3.307, 3.868, 4.795, 2.583; P<0.05). Compared with the ChT of the control group, there was no statistically significant difference in the superotemporal, region of the upper-dominant group (t=1.510, P>0.05); in other regions, the differences were statistically significant (t=3.207, 5.163, 2.526, 4.310, 6.285, 2.656, 3.812, 2.173; P<0.05). The differences in the foveal area and other areas in the symmetrical group were statistically significant (t=4.488, 5.554, 3.457, 5.314, 7.256, 3.507, 5.584, 6.019, 2.994; P<0.05). In the superotemporal, and superonasal, regions of the lower dominant group, the differences were not statistically significant (t=1.150, 1.465; P<0.05); in other regions, the differences were statistically significant (t=2.278, 4.168, 5.244, 2.783, 5.040, 3.432, 2.095; P<0.05). ConclusionThe dilated distribution of vortex veins on en-face ultra-wide-angle OCTA has a corresponding relationship with ChT. In eyes with CSC, the superior vortex vein drainage system may be the primary route for choroidal drainage.

          Release date:2024-06-18 11:04 Export PDF Favorites Scan
        • Progress of quantitative intravascular optical coherence tomography

          Intravascular optical coherence tomography (IVOCT) has emerged as a high-resolution and minimal-invasive imaging technique that provides high-speed visualization of coronary arterial vessel walls and clearly displays the vessel lumen and lesions under the intima. However, morphological gray-scale images cannot provide enough information about the tissue components to accurately characterize the plaque tissues including calcified, fibrous, lipidic and mixed plaques. Quantitative IVOCT (qIVOCT) is necessary to provide the physiological contrast mechanisms and obtain the characteristic parameters of tissues with clinical diagnostic value. In this paper, the progress of qIVOCT is reviewed. The current methods for quantitatively measuring optical, elastic and hemodynamic parameters of vessel wall and plaque tissues using IVOCT gray-scale images and raw backscattered signals are introduced and potential development is forecast.

          Release date:2020-06-28 07:05 Export PDF Favorites Scan
        • Comparison and correlation analysis of clinical and imaging features of focal choroidal excavation

          ObjectiveTo compare the clinical and imaging characteristics of eyes with idiopathic focal choroidal excavation (FCE) and acquired FCE, and to preliminarily analyze the association of FCE with different fundus diseases. MethodsA retrospective clinical study. A total of 90 patients (93 eyes) diagnosed with FCE at the Ophthalmology Department of The First Affiliated Hospital of Zhengzhou University from March 2021 to May 2024 were included in the study. All affected eyes underwent best-corrected visual acuity (BCVA) testing, intraocular pressure (IOP) measurement, ophthalmoscope, fundus color photography, and swept-source optical coherence tomography (SS-OCT). SS-OCT was used to measure subfoveal choroidal thickness (SFCT), choroidal thickness at the temporal, nasal, and inferior margins of the FCE, as well as the maximum width and depth of the FCE. Based on the presence of concomitant fundus diseases, FCE cases were divided into an idiopathic FCE group (51 eyes) and an acquired FCE group (42 eyes). Clinical characteristics at the initial and final visits were compared between the two groups. Clinical features were also analyzed for acquired FCE eyes with different associated fundus diseases. A logistic regression model was used to identify potential risk factors for FCE coexisting with other fundus diseases. ResultsCompared to the idiopathic FCE group, the acquired FCE group had significantly decreased BCVA (Z=?8.290), significantly increased FCE width (Z=?2.762), and significantly higher incidence rates of saucer-shaped FCE (χ2=8.352) and ellipsoid zone disruption (χ2=7.999). These differences were all statistically significant (P<0.05). No significant differences were found between the two groups in age, gender distribution, IOP, foveal involvement, proportion of conforming FCE, retinal pigment epithelium-Bruch’s membrane rupture, presence of hyperreflective material under the excavation, presence of surrounding thick vessels, FCE depth, SFCT, or choroidal thickness at the inferior, temporal, and nasal margins of the FCE (P>0.05). Logistic regression analysis revealed that FCE width (odds ratio=1.002, 95% confidence interval: 1.001-1.004, P=0.005) was the sole risk factor for FCE coexisting with other fundus complications. In both the idiopathic and acquired FCE groups, FCE depth and width remained relatively stable during follow-up. BCVA improved in the acquired FCE group after treatment. ConclusionsFCE can coexist with various fundus diseases. FCE width is the only risk factor for the development of other fundus complications in FCE-affected eyes. Treating retinal or choroidal diseases associated with acquired FCE can provide visual benefits to patients.

          Release date:2025-08-15 01:04 Export PDF Favorites Scan
        • Evaluation of the efficacy of a customized surgical approach for congenital optic disc pit with maculopathy

          Objective To observe the curative effect of a personalized surgical scheme based on scanning source optical coherence tomography (SS-OCT) image features in the treatment of congenital optic disc pit (ODP) with maculopathy (ODP-M). MethodsA prospective interventional cohort study. From September 2019 to May 2024, 15 patients with 15 eyes who were diagnosed with ODP-M by ophthalmology examination in Department of Ophthalmonogy of The First Affiliated Hospital of Zhengzhou University were included in the study. Best corrected visual acuity (BCVA) and SS-OCT were performed in all affected eyes. Standard E word visual acuity chart was used for BCVA examination, which was converted into logarithm of the minimum angle of resolution (logMAR) BCVA for record. The center retinal thickness (CRT) was measured by SS-OCT examination of macular area using VG200D of Henan SVision Imaging Technology Co., LTD. According to the morphological characteristics of ODP and the splitting, edema and detachment of macular region, combined with the degree of pulling of the boundary membrane between the posterior vitreous cortex and macular region, a personalized surgical method was designed. Class I: pars plana vitrectomy combined with macular boundary film stripping, ODP boundary film packing and vitreous cavity gas filling. Class Ⅱ: pars plana vitrectomy combined with non-retained macular boundary film stripping or ODP inner boundary film packing, vitreous cavity gas filling. Class Ⅰ and Class Ⅱ operations were performed in 10 and 5 eyes of 15 eyes, respectively. The postoperative follow-up time was >6 months. Follow-up time was performed with the same equipment before surgery. BCVA changes, CRT reduction rate and complications were observed. BCVA and CRT were compared before and after operation by paired sample t test. ResultsThere were 15 eyes in 15 cases, 4 eyes in 4 males and 11 eyes in 11 females. The age was (28.87±16.5) years. logMAR BCVA of the affected eye was 0.94±0.51. CRT was (697.80±301.80) μm. At the last follow-up, the logMAR BCVA was 0.53±0.49. CRT was (392.53±167.55) μm. Compared with before operation, BCVA and CRT were significantly improved, and the difference was statistically significant (t=3.23, 3.25; P=0.006, 0.006). After surgery, transient intraocular hypertension occurred in 2 eyes, and the intraocular pressure returned to normal level after 3 to 7 days without special treatment. Two eyes underwent an unexpected second operation. Among them, one eye underwent Class Ⅰ surgery, the tunnel at ODP was closed after surgery, and there was a small amount of subretinal fluid in the macular area. Class Ⅱ surgery was performed in 1 eye with retinal reattachment. ConclusionPersonalized surgical treatment of ODP-M based on SS-OCT image features can reduce CRT and improve visual acuity.

          Release date:2025-05-14 02:04 Export PDF Favorites Scan
        3 pages Previous 1 2 3 Next

        Format

        Content

          1. <div id="8sgz1"><ol id="8sgz1"></ol></div>

            <em id="8sgz1"><label id="8sgz1"></label></em>
          2. <em id="8sgz1"><label id="8sgz1"></label></em>
            <em id="8sgz1"></em>
            <div id="8sgz1"><ol id="8sgz1"><mark id="8sgz1"></mark></ol></div>

            <button id="8sgz1"></button>
            欧美人与性动交α欧美精品