• <xmp id="1ykh9"><source id="1ykh9"><mark id="1ykh9"></mark></source></xmp>
      <b id="1ykh9"><small id="1ykh9"></small></b>
    1. <b id="1ykh9"></b>

      1. <button id="1ykh9"></button>
        <video id="1ykh9"></video>
      2. west china medical publishers
        Keyword
        • Title
        • Author
        • Keyword
        • Abstract
        Advance search
        Advance search

        Search

        find Keyword "Optical coherence tomography angiography" 16 results
        • Advances in application of optical coherence tomography angiography for quantitative analysis in central serous chorioretinopathy

          Central serous chorioretinopathy (CSC) is one of the representative pachychoroid spectrum disease. Although fundus fluorescein angiography and indocyanine green angiography can be used as the gold standard for the diagnosis of CSC, they are invasive examinations, which may bring certain risks in clinical application and cannot help us obtain quantitative parameters. Optical coherence tomography angiography (OCTA), as a non-invasive and quantitative examination, is an important imaging tool for understanding the pathogenesis, diagnosis and treatment of CSC. With the advancement of OCTA, the swept-source OCTA has a satisfying scanning depth, a wider scanning range and a higher resolution. The development of OCTA broadens the horizons of the pathogenesis of CSC, promotes the understanding of the pathophysiology of CSC, and sheds new light for its clinical diagnosis and treatment. Based on OCTA, the choroid and retina in eyes with CSC are presented with qualitative and quantitative changes in vascular system. OCTA-guided CSC treatment and the discovery of prognostic markers based on OCTA challenge the application of traditional imaging techniques in CSC. With the continuous improvement and progress of OCTA technology, traditional angiography combined with OCTA will bring great benefits to the diagnosis and treatment of CSC. This review summarizes the quantitative application of OCTA in the pathogenesis, diagnosis and treatment of CSC.

          Release date:2023-05-18 10:05 Export PDF Favorites Scan
        • The macular structure and blood flow in familial exudative vitreoretinopathy with inner retinal layer persistence

          Objective To compared the changes of macular microvascular architecture in early stage familial exudative vitreoretinopathy (FEVR) patients with inner retinal layer (IRL) persistence and without IRL persistence. MethodsA retrospective clinical study. From 2017 to 2022, 94 patients with stage 1 FEVR with or without IRL residue and 45 age- and sex-matched healthy volunteers with 45 eyes (normal control group) who were confirmed by ophthalmology examination in Hangzhou Hospital of Optometry Affiliated to Wenzhou Medical University and Zhejiang Provincial People's Hospital were included in the study. According to whether there was IRL residue, the patients were divided into IRL group and non-IRL group, with 22 patients (22 eyes) and 72 patients (72 eyes), respectively. Best corrected visual acuity (BCVA) and optical coherence tomography angiography (OCTA) were performed in all eyes. Superficial vessel density (SCP) and deep vessel density (DCP) of whole image, fovea and parafovea, the area and perimeter of fovea avascular area (FAZ), A-circularity index (AI, perimeter/standard circle perimeter with equal area) and vessel density around the 300 μm width of the FAZ (FD), central macular thickness (CMT) on macular 3 mm × 3 mm scan on OCTA were measured. ResultsSCP and DCP of whole image (F=10.774, 4.583) and parafovea (F=10.433, 3.912), CMT (F=171.940) in IRL group and non-IRL group on macular 3 mm × 3 mm scan on OCTA were significantly lower than that in normal persons (P<0.05). There were significant differences among three groups of the area of FAZ (F=4.315), AI (F=3.413), FD-300 (F=13.592) (P<0.05). BCVA were worst in IRL group (P<0.05). ConclusionsBlood flow density decreased in macular area of FEVR patients. CMT is significantly thicker than normal population. The FAZ area of the foveal IRL residual eyes is small and irregular, with worse BCVA and lower macular blood density.

          Release date:2023-08-17 08:49 Export PDF Favorites Scan
        • Research progress of image artifacts in optical coherence tomography angiography

          Optical coherence tomography angiography (OCTA), as a non-invasive three-dimensional fundus vascular imaging technique, has significant advantages in the diagnosis and follow-up of eye diseases such as diabetic retinopathy and age-related macular degeneration. However, the existence of OCTA image artifacts has seriously affected its clinical application. These artifacts are caused by various factors such as image acquisition, internal characteristics of the eyeball, eye movement and image processing, such as weak signals, blinking, defocusing, bands, tilting, occlusion, exposure, projection, movement and layering, leading to vascular quantization deviation, lesion blurring and image distortion, thereby reducing the accuracy of clinical diagnosis. To address this issue, researchers have proposed a variety of correction strategies, including enhancing signal strength, optimizing equipment, developing algorithms to identify and eliminate shadow artifacts, using hardware or software methods for motion correction, and employing deep learning algorithms for image quality assessment and artifact removal. Constructing a unified and systematic framework for artifact cognition and processing is crucial for enhancing the reliability of OCTA diagnostic results and will drive the level of ophthalmic diagnosis and treatment to a new height.

          Release date: Export PDF Favorites Scan
        • Consistency analysis of optical coherence tomography angiography and fundus fluorescein angiography in the diagnosis of central retinal vein occlusion

          Objective To assess the consistency of diagnostic results using optical coherence tomography angiography(OCTA) and fundus fluorescein angiography(FFA) in the central retinal vein occlusion(CRVO). Methods A retrospective case series of 26 eyes of 26 patients with CRVO. Simultaneous OCTA and FFA were performed in all patients by using 7-standard field of ETDRS to evaluate the microaneurysms, nonperfused areas, optical disc/retinal neovascularization and macular edema. The consistency was evaluated using weightedKappa statistic values.Kappa≥0.75, consistency is excellent; 0.60≤Kappa<0.75, consistency is good; 0.40≤Kappa<0.60, consistency is general;Kappa<0.40, consistency is poor. Results Examined by OCTA, microaneurysms were found in 23 eyes, nonperfused areas in 16 eyes, optical disc/retinal neovascularization in 8 eyes and macular edema in 21eyes. Performed with FFA, 23 eyes were diagnosed to have microaneurysms, 16 eyes have nonperfused, 8 eyes have optical disc/retinal neovascularization, 22 eyes have macular edema. The consistency was excellent for microaneurysms(Kappa=0.772,P<0.01) and optical disc/retinal neovascularization(Kappa=0.766,P<0.01), good for nonperfused areas (Kappa=0.703,P<0.01) and macular edema(Kappa=0.60,P<0.01). Conclusion There is high consistency between OCTA and FFA in the diagnosis of CRVO, OCTA is an effective method in the examination of CRVO.

          Release date: Export PDF Favorites Scan
        • Efficacy of optical coherence tomography angiography guided half-dose photodynamic therapy in the treatment of acute central serous chorioretinopathy

          ObjectiveTo observe the efficacy of optical coherence tomography angiography (OCTA) guided half-dose photodynamic therapy (PDT) in the treatment of acute central serous chorioretinopathy (CSC). MethodsA prospective randomized controlled trial. A total of 72 patients (72 eyes) with acute CSC in Peking University People's Hospital from April 2019 to April 2020 were included in the study. They were randomly divided into OCTA group (OCTA-guided PDT, 31 eyes of 31 patients) and indocyanine green angiography (ICGA) group (ICGA-guided PDT, 33 eyes of 33 patients). All patients underwent best corrected visual acuity (BCVA), fundus color photography, OCTA and ICGA examinations. International standard visual acuity chart was used for BCVA examination, which was converted into logarithm of the minimum angle of resolution (logMAR) visual acuity. In OCTA group, the hyper-reflective area on en face OCTA image at choriocapillaris level was identified as treating area. In ICGA group, the area of choroidal vascular hyperpermeability on ICGA which was related to the leakage on fundus fluorescein angiography (FFA) was identified as treating area. The area corresponding to the treating area on FFA or ICGA was outlined on the color fundus photograph to guide PDT laser spot. The complete subretinal fluid (SRF) resolution, BCVA, central retinal thickness (CRT) at 1, 3, 6 months and SRF recurrent rate at 3, 6 months were observed. Continuous variables between the two groups were compared by t-test or Wilcoxon rank sum test. The χ2 test was used to compare the categorical variables. ResultsAt 1, 3 and 6 months after treatment, the SRF absorption rate in OCTA group and ICGA group was 74.2% (23/31), 63.6% (21/33), 87.1% (27/31) and 84.8% (28/33), 96.8% (30/31), 91.9% (31/33), respectively. OCTA-guided PDT was demonstrated noninferior to ICGA-guided PDT for complete SRF resolution at 1, 3, 6 months [95% confidence interval (CI) -11.9%-33.1%, P=0.402; 95%CI -14.7%-19.3%, P=0.107; 95%CI -6.3%-16.1%, P=0.226]. There was no significant difference in the recurrence rate of SRF between the two groups at 3 and 6 months after treatment (χ2=0.009, 0.047; P=0.925, 0.828). The difference of CRT was statistically significant at 6 months (t=2.017, P=0.047). There was no significant difference in logMAR BCVA at 1, 3 and 6 months after treatment (t=0.529, 0.762, 1.017; P=0.581, 0.403, 0.243). ConclusionsDuring 6 months follow-up, OCTA-guided PDT was demonstrated noninferior to ICGA-guided PDT for the SRF absorption rate in patients with acute CSC.

          Release date:2023-05-18 10:05 Export PDF Favorites Scan
        • Study of optical coherence tomography angiography for myopic choroidal neovascularization

          Objective To analyze the characteristics of myopic choroidal neovascularization (mCNV) and the outcome of intravitreal anti-vascular endothelial growth factor (VEGF) treatment by using optical coherence tomography angiography (OCTA). Methods A prospective study was carried out, which included 34 eyes of 31 patients with mCNV in West China Hospital of Sichuan University between May and December 2017. OCTA scans were conducted to all patients before treatment, 1 day, 1 week, 1 month and 3–6 months after treatment. The analysis was performed to evaluate the morphological characteristics, lesion area, parafoveal superficial vessel density and perfusion area of choroidal neovascularization before and after treatment. Results Among mCNV patients, small round crumby lesions, small branches, and capillaries responded well to anti-VEGF treatment. Compared with the mean lesion area in mCNV patients before treatment [(0.082±0.013) mm2], there was instant reduction 1 day after treatment [(0.064±0.013) mm2] and obviously decreased after 1 week [(0.046±0.011) mm2]. The parafoveal superficial vessel density and perfusion area before treatment were (15.2±0.5)% and (32.6±1.5)%, respectively, and obvious decrease was observed both in parafoveal superficial vessel density [(12.1±0.9)%] and perfusion area [(27.4±2.0)%] 1 day after treatment in mCNV patients, which began to recover 1 month after treatment. Conclusions OCTA is a non-invasive diagnostic examination, which can clearly identify tiny structures of mCNV, quantify the lesion area and display specific vasculature in mCNV patients. Furthermore, retinal microcirculation can be detected by using OCTA, which provides an effective approach of monitoring the progression and treatment effect of mCNV.

          Release date:2018-11-22 04:28 Export PDF Favorites Scan
        • Preliminary observation of the effect of cystic cavity on visual function of macular area before and after operation in idiopathic macular hole

          ObjectiveTo observe and analyze the effect of peripore cavity size on visual function of macular area before and after surgery for idiopathic macular hole (IMH). MethodsA retrospective clinical study. From July 2020 to February 2021, a total of 25 patients with 25 eyes with monocular IMH (operation group) diagnosed by ophthalmology examination in Department of ophthalmology, Fourth Hospital of Hebei Medical University were included in the study. The control group was contralateral healthy eyes. All subjects were examined by best corrected visual acuity (BCVA), microfield of vision, frequency domain optical coherence tomography (SD-OCT), and OCT angiography (OCTA). The diameter of macular hole was measured by SD-OCT. The cystic morphology of deep capillary plexus (DCP) was detected by en face OCT, and the cystic area was measured by Image J software. MP-3 microperimeter was used to measure central macular retinal light sensitivity (MS) and mean macular retinal light sensitivity (MMS). Central macular retinal light sensitivity (CMS), MMS and cystic cavity MS were measured in the operation group. MMS was measured in the control group. The microperimetry images were superimposed on the DCP layer of OCTA to identify and calculate the average MS within the lumen and compare it with the control group. Standard three incisions were performed in all affected eyes by vitrectomy of the flat part of the ciliary body + stripping of the inner boundary membrane + intraocular sterile air filling. Three months after the operation, the same equipment and methods were used to perform relevant examinations. Paired sample t test was used to compare MS between operation group and control group. Pearson correlation analysis was used to analyze the correlation between capsular area, macular hole diameter before and after operation and MS before and after operation. The correlation between BCVA and capsular area before and after surgery was analyzed by Spearman correlation analysis. ResultsIn the surgical group, the retinal MS was (4.24±3.07) dB. The MMS of control group was (19.08±6.11) dB. The MS in the surgical group was significantly lower than that in the control group, and the difference was statistically significant (t=10.832, P<0.01). Before operation, the area of cyst was (1.04±0.55) mm2, and the diameter of macular hole was (564.80±166.59) μm. CMS and MMS were (2.27±2.29) dB and (9.08±3.65) dB, respectively. The diameter of macular hole (r=0.50, P=0.010) and BCVA before operation (r=0.57, P<0.001) were positively correlated with peripore cavity area. Before operation, CMS and MMS were negatively correlated with peripore cavity area (r=-0.53, -0.47; P=0.010, 0.020). At 3 months after surgery, the capsular area was negatively correlated with CMS and MMS (r=-0.65,-0.76; P=0.020, 0.030). There was no correlation with BCVA (r=0.23, P=0.470). ConclusionsRetinal MS is decreased in the peri-capsular area of IMH pore. There is a positive correlation between capsule area, BCVA and macular hole diameter before operation. The capsular area is negatively correlated with CMS and MMS before operation.

          Release date:2023-12-27 08:53 Export PDF Favorites Scan
        • Observation on the blood flow changes around the optic disc before and after the combined treatment of anti-vascular endothelial growth factor and Dexamethasone intravitreal implant for central retinal vein occlusion

          ObjectiveTo observe changes in peripapillary blood flow before and after combined treatment with anti-vascular endothelial growth factor (VEGF) drugs and Dexamethasone intravitreal implant (DEX) in patients with central retinal vein occlusion (CRVO). MethodsA prospective clinical study. Thirty-three eyes of 33 patients with newly diagnosed non-ischemic CRVO and macular edema (ME) were enrolled from Shanxi Eye Hospital between April 2023 and April 2024. All patients underwent best-corrected visual acuity (BCVA) and swept-source optical coherence tomography angiography (SS-OCTA) examinations. The treatment regimen consisted of three intravitreal injections of ranibizumab and one DEX implant. SS-OCTA was used to scan a 3 mm×3 mm area centered on the optic disc to measure peripapillary retinal nerve fiber layer (RNFL) thickness and blood flow density in the superficial vascular complex (SVC), deep vascular complex (DVC), and radial peripapillary capillaries (RPC). Changes in SVC, DVC, and RPC blood flow density and RNFL thickness were evaluated at 3 and 6 months post-treatment. Shapiro-Wilk test was used to assess normality, and Spearman's rank correlation coefficient was applied for correlation analysis. ResultsCompared with before treatment, the blood flow density changes of SVC and RPC showed a downward trend at 3 and 6 months after treatment. Among them, the difference was statistically significant at 6 months after treatment (Z=?2.592, ?2.070, P=0.012, 0.042), while there was no statistically significant difference at 3 months after treatment (P>0.05). The blood flow density of DVC showed an upward trend at 3 and 6 months after treatment, but the differences were not statistically significant (P>0.05). The results of the correlation analysis showed that the thickness of RNFL was negatively correlated with the blood flow density of DVC (r=?0.768, P<0.001). It was positively correlated with the blood flow densities of SVC and RPC (r=0.288, 0.398; P=0.040, 0.004). ConclusionAnti-VEGF drugs combined with DEX treatment can significantly improve the perioptic disc blood flow distribution in eyes with CRVO, manifested as a decrease in blood flow density of SVC and RPC, while a compensatory increase in blood flow of DVC. The thickness variation of RNFL is closely related to the blood flow density of different vascular layers.

          Release date: Export PDF Favorites Scan
        • Multimodal imaging analysis of acute macular neuroretinopathy in the coronavirus disease 2019 infection

          ObjectiveTo observe the clinical and multimodal imaging features of eyes with acute macular neuroretinopathy (AMN) associated with the coronavirus disease 2019 (COVID-19). MethodsA retrospective study. From December 20, 2022 to January 17, 2023, a total of 29 patients (58 eyes) with COVID-19-associated AMN admitted to Department of Ophthalmology of Eye and ENT Hospital, Shanghai Medical College were included in the study. All the affected eyes underwent the best corrected visual acuity, color fundus photography, infrared fundus photography (IR), short-wavelength autofluorescence (SW-AF), near-infrared autofluorescence (NIL-AF), optical coherence tomography (OCT), and OCT angiography (OCTA). All patients were administered microcirculation-improving oral medication with 12 cases receiving adjunctive low-dose corticosteroid therapy. Follow-ups were conducted 1 to 3 months after the initial diagnosis, with a total of 19 cases (38 eyes) completing the one-month follow-up. ResultsOut of the 29 cases, there were 9 males (18 eyes) and 20 females (40 eyes), all of whom experienced bilateral eye involvement. The age of the patients ranged from 12 to 47 years, with an average age of (29.9±9.5) years. The time from the onset of fever to the appearance of ocular symptoms was (2.52±2.01) days. Among the 58 affected eyes, there were 5 cases with retinal cotton wool spots, 2 cases with optic disc edema, and 1 case with parafoveal branch retinal vein occlusion. All affected eyes exhibited deep reddish-brown macular dark spots. IR revealed wedge-shaped, wedge-like, or "petaloid-like" dark areas involving the fovea and parafovea. SW-AF examination showed no obvious abnormality in 39 eyes. Weak autofluorescence dark area were consistent with IR in 19 eyes. NIR-AF examination showed spot-like or flaky self-fluorescent dark areas. OCT examination showed strong reflex lesions spreading vertically upward from the retinal pigment epithelium (RPE) layer in the macular area in the acute stage, showing typical "bean seedling" sign. OCTA revealed reduced blood flow density in the deep capillary plexus (DCP) of 50 eyes. En-face OCT displayed lesion areas that corresponded to the dark areas seen in IR. One month after the initial diagnosis, the condition improved in 18 eyes (47.4%, 18/38). Among the 5 eyes with cotton wool spots, regression of these spots was accompanied by loss of nerve fiber layer in 4 eyes. In cases with optic disc edema, the edema subsided. The "bean sprout" sign disappeared in all affected eyes, and the lesions became localized. The ellipsoid zone and/or interdigitation zone in the lesion areas were discontinuous. ConclusionsCOVID-19-related AMN is characterized by distinctive features. IR fundus reveals wedge-shaped, wedge-like, or petaloid dark areas involving the fovea and parafovea. OCT displays strongly reflective lesions with vertical spread above the RPE. OCTA shows reduced blood flow density in the DCP of the retina.

          Release date:2023-09-12 09:11 Export PDF Favorites Scan
        • Diagnostic value of optical coherence tomography angiography in primary open-angle glaucoma: a meta-analysis

          ObjectiveTo systematically review the diagnostic value of optical coherence tomography angiography (OCTA) for primary open-angle glaucoma (POAG). MethodsThe CNKI, WanFang Data, VIP, CBM, PubMed, Embase, Web of Science, and Cochrane Library databases were electronically searched to collect diagnostic test on OCTA for POAG from inception to February 2024. Two reviewers independently screened literature, extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed by using Stata 15.0 software. ResultsA total of 12 diagnostic tests involving 993 subjects were included. Meta-analysis results showed that the sensitivity/specificity of OCTA for diagnosing peripapillary vessel density, retinal vessel density, and optic nerve fiber changes in patients with POAG were 0.77/0.92, 0.56/0.92, and 0.85/0.91, respectively, and the AUC of the SROC curve was 0.94, 0.92 and 0.95, respectively. ConclusionOCTA has high diagnostic accuracy for POAG. Due to the limited quality and quantity of the included studies, more high quality studies are needed to verify the above conclusion.

          Release date:2025-02-25 01:10 Export PDF Favorites Scan
        2 pages Previous 1 2 Next

        Format

        Content

      3. <xmp id="1ykh9"><source id="1ykh9"><mark id="1ykh9"></mark></source></xmp>
          <b id="1ykh9"><small id="1ykh9"></small></b>
        1. <b id="1ykh9"></b>

          1. <button id="1ykh9"></button>
            <video id="1ykh9"></video>
          2. 射丝袜