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find Keyword "optical coherence tomography" 23 results
  • Study on the relationship between retinal and choroidal blood flow and the pathogenesis of idiopathic macular hole

    Objective To compare changes in retinal and choroidal blood flow in the macular area of eyes with idiopathic macular hole (IMH), fellow eyes, and normal eyes. Additionally, the correlation between these blood flow changes and the occurrence and development of IMH. Methods A cross-sectional study. From January 2023 to January 2024, 47 patients (47 eyes) diagnosed with IMH (IMH group) in Department of Ophthalmology of The Second Hospital of Hebei Medical University were included in the study. The contralateral eye of IMH eyes was assigned to the contralateral eye group. Healthy volunteers with matched gender and age were selected as the normal control group. Swept-source optical coherence tomography angiography was used to acquire the vessel density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the areas within 0-1 mm and 1-6 mm around the fovea, including the superior, temporal, inferior, and nasal regions. Additionally, the choroidal blood flow area (CBFA) and three-dimensional choroidal vascular index (3D-CVI) were measured. The minimum linear diameter (MLD) and base diameter (BD) of the IMH were manually measured. Spearman correlation analysis was performed to evaluate the correlation between the size of the IMH and the various vascular parameters. ResultsCompared with the normal control group, the SCP-VD in the 3rd stage (t=1.298, P=0.009) and 4th stage (t=1.264, P<0.000) eyes in the IMH group was significantly decreased, with statistical significance; the DCP-VD (t=1.958, 2.150, 1.712, 1.667; P=0.027, <0.000, <0.000, <0.000) and 3D-CVI (t=0.027, 0.030, 0.024, 0.023; P=0.005, 0.003, <0.000, <0.000) in eyes of all stages were significantly decreased, with statistical significance; the CBFA in eyes of stages 2-4 was significantly decreased, with statistical significance (t=0.027, 0.022, 0.021; P=0.028, 0.002, 0.002). Compared with the contralateral eye group, the DCP-VD and 3D-CVI in the IMH group were significantly reduced, with statistical significance (Z=−3.289, −2.704; P=0.001, 0.007). Pairwise comparisons between eyes of different stages in the IMH group showed that SCP-VD was significantly different between stage 2 and stage 4 (t=1.776, P=0.008); DCP-VD was significantly different between stage 1 and stage 3, and stage 1 and stage 4 (t=1.685, 1.661; P=0.002, 0.000). Correlation analysis showed that SCP-VD was negatively correlated with MLD and BD (r=−0.508, −0.408; P=0.002, 0.014); DCP-VD was negatively correlated with BD (r=−0.410, P=0.013). Compared with the normal control group, the nasal CBFA in stage 3 and 4 IMH eyes (t=0.149, 0.145; P=0.005, 0.002), and the nasal 3D-CVI in stage 1 and 3 IMH eyes (t=0.030, 0.027; P=0.002, <0.000) were significantly decreased, with statistical significance. ConclusionsThe SCP-VD, DCP-VD, CBFA, and 3D-CVI in IMH eyes were significantly reduced. SCP-VD showed a negative correlation with MLD and BD, while DCP-VD was only negatively correlated with BD.

    Release date:2025-08-15 01:04 Export PDF Favorites Scan
  • Retinal vascular characteristics in patients with obstructive sleep apnea syndrome assessed by optical coherence tomography angiography: a meta-analysis

    Objective To evaluate the application value of optical coherence tomography angiography (OCTA) in obstructive sleep apnea syndrome (OSAS). Methods A comprehensive search of both domestic and international databases was conducted to identify clinical studies on the use of OCTA in OSAS, from the establishment of the databases to May 2024. A meta-analysis was performed using Revman 5.4 software. Results A total of 134 studies were initially identified, with 14 studies meeting the inclusion criteria, encompassing 999 subjects (739 in the OSAS group and 260 in the healthy group). Meta-analysis results indicated that the superficial capillary plexus (SCP) density in the fovea (MD=–2.05, 95%CI –3.75 to –0.35, P=0.02) and parafovea (MD=–1.56, 95%CI –2.44 to –0.68, P=0.000 5) was significantly lower in the OSAS group compared with the healthy group. In the mild to moderate OSAS group, SCP density was significantly lower in the fovea (MD=–2.41, 95%CI –4.32 to –0.49, P=0.01), parafovea (MD=–1.17, 95%CI –2.01 to –0.32, P=0.007), and perifovea (MD=–1.73, 95%CI –2.69 to –0.77, P=0.000 4) compared with the healthy group. In the severe OSAS group, SCP density in the perifovea (MD=–1.33, 95%CI –2.53 to –0.13, P=0.03) was significantly lower than that of the healthy group. SCP density in the whole area (MD=0.36, 95%CI 0.05 to 0.68, P=0.02) was significantly higher in the mild to moderate OSAS group compared with the severe OSAS group. In the deep capillary plexus (DCP) density, the OSAS group showed significantly lower densities in the whole area (MD=–2.16, 95%CI –3.51 to –0.81, P=0.002), fovea (MD=–2.38, 95%CI –4.38 to –0.37, P=0.02), and parafovea (MD=–2.33, 95%CI –3.93 to –0.73, P=0.004) compared with the healthy group. The mild to moderate OSAS group also showed significantly lower densities in the whole area (MD=–2.02, 95%CI –3.33 to –0.72, P=0.002) and parafovea (MD=–1.65, 95%CI –3.04 to –0.26, P=0.02) compared with the healthy group. The severe OSAS group had significantly lower DCP density in the whole area (MD=–2.26, 95%CI –3.85 to –0.66, P=0.006) and parafovea (MD=–1.47, 95%CI –2.31 to –0.62, P=0.000 7) compared with the healthy group. DCP density in the whole area (MD=0.54, 95%CI 0.02 to 1.07, P=0.04) was significantly higher in the mild to moderate OSAS group compared with the severe OSAS group. Regarding the retinal nerve fiber layer (RNFL) thickness, the inferior quadrant (MD=4.01, 95%CI 0.69 to 7.32, P=0.02) and temporal quadrant (MD=4.35, 95%CI 1.88 to 6.82, P=0.000 6) were significantly thicker in the mild to moderate OSAS group compared with the severe OSAS group. In terms of the foveal avascular zone (FAZ) area, the severe OSAS group showed a significantly larger FAZ area (MD=0.06, 95%CI 0.03 to 0.08, P<0.000 01) compared with the healthy group. Conclusion OCTA-related ocular biomarkers may be associated with the occurrence and progression of OSAS and have potential applications in the diagnosis and treatment of OSAS.

    Release date:2025-03-25 01:25 Export PDF Favorites Scan
  • Pathological diagnostic value of respiratory optical coherence tomography in lung cancer

    Objective To explore the pathological diagnostic value of optical coherence tomography (OCT) in lung cancer. Methods This study selected patients who underwent general anesthesia and electronic bronchoscope biopsy at the Respiratory Endoscopy Center of Sichuan Provincial People’s Hospital from January 1, 2023, to December 1, 2023. White-light bronchoscopy (WLB), auto-fluorescence bronchoscopy (AFB), and OCT examinations were performed in all patients. Lesions were assessed for benign or malignant characteristics based on AFB and OCT before biopsy. The final pathological results were determined according to pathology report. Results A total of 124 patients were included in the study. The accuracy of OCT in differentiating the nature of lesions was 93.55%, significantly higher than AFB (accuracy 83.06%). The accuracy, sensitivity, and specificity of OCT were all higher than AFB. For squamous carcinoma, adenocarcinoma, and small cell lung cancer, the accuracy rates of OCT imaging characteristics were 91.94%, 94.35%, and 94.35%, respectively. Conclusion OCT can improve the accuracy of pre-bronchoscopic tissue pathology biopsy in determining the nature of lesions and provide rapid pathological typing basis, potentially further promoting the development of non-invasive histological biopsy.

    Release date:2024-05-16 01:48 Export PDF Favorites Scan
  • Peripheral retinopathy under intraoperative optical coherence tomography

    ObjectiveTo observe the histopathological changes in peripheral retinal lesions under intraoperative optical coherence tomography (iOCT). Methods A retrospective case series study. Eighty-eight patients (194 eyes) who underwent vitreoretinal surgery in the Department of Ophthalmology at the East Ward of the First Affiliated Hospital of Zhengzhou University from October 2021 to May 2022 in 94 eyes were included in the study. Among them, 49 cases were male and 39 cases were female, with the mean age of (50.93±17.55) years. Ninety-four eyes included 32 eyes with retinal detachment, 6 eyes with proliferative diabetic retinopathy, 28 eyes with vitreous hemorrhage, 8 eyes with ocular trauma, 14 eyes with the macular lesion, 1 eye with uveitis, 1 eye with family exudative vitreoretinopathy (FEVR), 1 eye with acute retinal necrosis (ARN), and 3 eyes with lens dislocation. All affected eyes were examined with iOCT during vitreoretinal surgery. The iOCT scanning of the peripheral retina was performed with the help of episcleral pressure. The pre-equatorial and serrated edge anterior and posterior of retinas were scanned according to the characteristics of different fundus diseases. Various abnormal fundus manifestations were recorded. Results In 94 eyes, 53 eyes (56.38%, 53/94) have different types of retinopathy in the peripheral retina. Of these, 7 eyes (7.45%) have retinal cystoid degeneration; 19 eyes (20.21%) have lattice degeneration; and 8 eyes (8.51%) have pigment degeneration; 9 eyes (9.57%) have pavement-like degeneration; 7 eyes (7.45%) have small occult holes; 1 eye (1.06%) has familial exudative vitreoretinopathy (FEVR) serrated edge "dyke-like" proliferative degeneration; 4 eyes (4.26%) have vitreous and retinopathy adhesions; and one eye (1.06%) has ARN. Conclusion With clear refractive media, iOCT can provide clear scans of different peripheral retinal lesions.

    Release date:2023-05-18 10:05 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
  • 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
  • Analysis of macular vascular density and retinal thickness of school-age children

    ObjectiveTo observe the correlation between retinal capillary density and retinal thickness in the macula and spherical equivalent (SE) in school-age children. MethodsA cross-sectional study. From May to December 2022, 182 school-age children who visited the ophthalmology department of the First Affiliated Hospital of Zhengzhou University were included . There were 95 males and 87 females. The age ranged from 6 to 12 years, and the spherical equivalent (SE) was +0.50 to -6.00 D. They were divided into three groups based on the SE of the right eyes: 54 eyes in emmetropia group (+0.50≤SE<-0.50 D), 71 eyes in low myopia group (-0.50≤SE<-3.00 D), and 57 eyes in moderate myopia group (-3.00≤SE≤-6.00 D). The macular area of 6 mm×6 mm was scanned using swept-source optical coherence tomography angiography and was divided into three concentric rings centered on the fovea, including the macular central fovea (0-1 mm diameter), inner ring (1-3 mm diameter) and outer ring (3-6 mm diameter). The retinal thickness and blood flow density of superficial vascular plexus (SVP) and deep vascular plexus (DVP) in different zones within 6 mm of the macular area were measured. The relationships between SE and SVP, DVP and retinal thickness in each ring region were investigated by univariate and multivariate linear regression analyses, smooth curve fitting, and threshold effects. ResultsThere were significant differences in the SVP (F=6.64, 26.06, 22.69) and DVP (F=7.97, 25.01, 5.09) of macular central fovea, inner ring and outer ring among the emmetropia, low myopia and moderate myopia groups (P<0.05). Univariate linear regression analysis showed that the SVP (β=-0.56, -1.17, -0.79) and DVP (β=-1.03, -0.93, -0.45) of the three regions were positively correlated with SE (P<0.05). After smooth curve fitting, threshold effect analysis and multivariate linear regression analysis, the SVP and DVP in the macular central fovea were linearly positively correlated with SE (β=-0.91, -1.40; P<0.05), and SVP and DVP in the inner ring and outer ring showed an inverted U-shaped curve relationship with SE with the inflection (<3.00 D). When the SE was less than <3.00 D, the SVP and DVP in the inner ring and outer ring were positively correlated with SE (P<0.05). When the SE was higher than -3.00 D, except for the DVP in the inner ring region, the other parameters were negatively correlated with SE (P<0.05). There were significant differences in retinal thickness of the inner ring and outer ring (F=5.47, 16.36; P<0.05), and no significant difference in the macular central fovea among the emmetropia, low and moderate myopia groups (F=2.16, P>0.05). By using univariate and multivariate linear regression analyses, the retinal thickness in the inner ring and outer ring were negatively correlated with SE (β =1.99, 3.05; P<0.05). However, no correlation was found between retinal thickness and SE in the macular central fovea (β=-1.65, P>0.05). ConclusionsIn school-age children with SE between +0.50 D and -6.00 D, the retinal capillaries density of the macular central fovea gradually increase, and increase first and then decrease in the inner ring and outer ring with increasing SE. The retinal thickness of inner ring and outer ring gradually decrease and not change significantly in the macular central fovea.

    Release date:2024-01-23 05:54 Export PDF Favorites Scan
  • Evaluation of Anterior Segment Parameters of Hyperopia of School-aged Children Using Anterior Segment Optical Coherence Tomography

    The aim of this study was to investigate the feasibility of anterior segment optical coherence tomography to assess the anterior segment morphology of hyperopia in school-aged children. 320 eyes of 160 school-aged children, 6-12 years of age, were examined with anterior segment optical coherence tomography and were divided into four groups according to the cycloplegic spherical equivalence of refractive error. The mentioned four groups were: emmetropia group, low hyperopia group, moderate hyperopia group and high hyperopia group. The measurements of central corneal thickness, anterior chamber depth, angle opening distance, trabecular iris space area and scleral angle were compared in pairs among objects in the four groups. The results showed that high hyperopia and moderate hyperopia had shallower anterior chamber depth and narrower anterior chamber angle compared to those in emmetropia group. The study also showed that anterior segment optical coherence tomography as a non-contact technology could become a new technology for accessing the anterior segment morphology of hyperopia in school-aged children.

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  • 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
  • Plaque segmentation of intracoronary optical coherence tomography images based on K-means and improved random walk algorithm

    In recent years, optical coherence tomography (OCT) has developed into a popular coronary imaging technology at home and abroad. The segmentation of plaque regions in coronary OCT images has great significance for vulnerable plaque recognition and research. In this paper, a new algorithm based on K-means clustering and improved random walk is proposed and Semi-automated segmentation of calcified plaque, fibrotic plaque and lipid pool was achieved. And the weight function of random walk is improved. The distance between the edges of pixels in the image and the seed points is added to the definition of the weight function. It increases the weak edge weights and prevent over-segmentation. Based on the above methods, the OCT images of 9 coronary atherosclerotic patients were selected for plaque segmentation. By contrasting the doctor’s manual segmentation results with this method, it was proved that this method had good robustness and accuracy. It is hoped that this method can be helpful for the clinical diagnosis of coronary heart disease.

    Release date:2017-12-21 05:21 Export PDF Favorites Scan
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