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        find Keyword "optical coherence tomography" 24 results
        • 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
        • 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
        • 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
        • An optical coherent imaging system for measuring the strain of blood vessels

          We aimed to establish an optical coherence tomography (OCT) system to measure the strain of blood vessels. A general OCT system was constructed firstly and its reliability was confirmed by comparing the OCT imaging of the porcine coronary and the corresponding histological slices. The strain of the porcine coronary was induced by static flow pressure and correlation algorithm was used to calculate the strain field of blood vessels within OCT images. The results suggest that bright-dark stratification of blood vessels displayed in OCT images is consistent with the intima and media layers of histological image. Furthermore, the strain of media layer is greater than that of the intima layer under the same static pressure. The optical coherence imaging system could not only measure the histological structure of the blood vessels, but also qualify the vessel strain under flow pressure.

          Release date:2017-10-23 02:15 Export PDF Favorites Scan
        • Observation of vortex venous anastomosis in central serous chorioretinopathy

          Objective To observe the anastomotic status of the vortex veins in patients with central serous chorioretinopathy (CSC). MethodsA cross-sectional study of clinical practice. From July 2021 to July 2022, 50 cases (50 eyes) of monocular CSC patients diagnosed through ophthalmic examination at the First Affiliated Hospital of Zhengzhou University were included in the study. Among them, there were 37 males (74.0%, 37/50) and 13 females (26.0%, 13/50), with the mean age of (44.30±9.59) years old. The course of disease from the onset of symptoms to the time of treatment was less than 3 months. The affected eye and contralateral eye of CSC patients were divided into the affected eye group and contralateral eye group, respectively. Fifty healthy volunteers of the same age and gender were selected as the normal control group with 50 eyes. The macular area scanning source optical coherence tomography (OCT) vascular imaging examination was performed with Visual Microimaging (Henan) Technology Co., Ltd. VG200D. Horizontal watershed vortex veins anastomosis rate and asymmetric vortex-venous dilation rate were observed by en face OCT. The device comes with software to calculate the central foveal choroidal thickness (SFCT), mean choroidal thickness (MCT), and choroidal vascular index (CVI). One-way analysis of variance and χ2 test were used to compare the three groups. When variances were unequal between groups, nonparametric tests were performed. ResultsThe SFCT values of the affected eye group, contralateral eye group, and normal control group were (567.12±129.02), (513.26±133.17), (327.64±97.40) μm, respectively; MCT were (407.38±97.54), (388.24±94.13), (275.46±60.55) μm, respectively; CVI were 0.34±0.05, 0.32±0.04, and 0.27±0.04, respectively; anastomosis rates of vortex veins were 98% (49/50), 78% (39/50), and 40% (20/50), respectively; asymmetric dilation rates of vortex veins were 96% (48/50), 88% (44/50), and 48% (24/50), respectively. The differences of SFCT (F=53.974), MCT (Z=51.415), CVI (F=28.082), vortex vein anastomosis rate (χ2=43.056), asymmetric dilation rate of vortex veins (χ2=37.728) among three groups were statistically significant (P<0.001). Compared with the contralateral eye group, the SFCT, MCT, CVI, vortex vein anastomosis rate, and vortex vein asymmetric dilation rate in the affected eye group were significantly higher than those in the contralateral eye group. Among them, the differences of SFCT (t=2.054), CVI (t=2.211), and vortex vein anastomosis rate (χ2=9.470) were statistically significant (P<0.05); the differences of MCT (Z=7.490), asymmetric dilation rate of vortex veins(χ2=2.714) were not statistically significant (P=1.000, 0.140). ConclusionsSFCT, MCT, and CVI in the affected and contralateral eyes of monocular CSC patients significantly increase. The anastomotic rate and asymmetric dilation rate of the vortex vein in the opposite eye were lower than those in the affected eye.

          Release date:2023-05-18 10:05 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
        • 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
        • 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
        • Plaque region segmentation of intracoronary optical cohenrence tomography images based on kernel graph cuts

          The segmentation of the intracoronary optical coherence tomography (OCT) images is the basis of the plaque recognition, and it is important to the following plaque feature analysis, vulnerable plaque recognition and further coronary disease aided diagnosis. This paper proposes an algorithm about multi region plaque segmentation based on kernel graph cuts model that realizes accurate segmentation of fibrous, calcium and lipid pool plaques in coronary OCT image, while boundary information has been well reserved. We segmented 20 coronary images with typical plaques in our experiment, and compared the plaque regions segmented by this algorithm to the plaque regions obtained by doctor's manual segmentation. The results showed that our algorithm is accurate to segment the plaque regions. This work has demonstrated that it can be used for reducing doctors' working time on segmenting plaque significantly, reduce subjectivity and differences between different doctors, assist clinician's diagnosis and treatment of coronary artery disease.

          Release date:2017-04-01 08:56 Export PDF Favorites Scan
        • Evolution of optical coherence tomography

          Optical coherence tomography (OCT) is a non-invasive, rapid optical medical imaging modality and has become a hot topic in biomedical research. In recent years, several functional OCTs have emerged, including Doppler OCT, polarization-sensitive OCT, spectroscopic OCT, and optical coherence tomographic elastography, etc. These newer advances in functional OCT broaden the potential clinical application of OCT by providing novel ways to observe and understand tissue activity that cannot be accomplished by other current imaging methodologies.

          Release date:2018-11-22 04:28 Export PDF Favorites Scan
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