To classify retinal neovascularization in untreated early stages of proliferative diabetic retinopathy (PDR) based on optical coherence tomography angiography (OCTA).
A cross-sectional study.
...Thirty-five eyes were included. They underwent color fundus photography, fluorescein angiography (FA), and OCTA examinations. Neovascularizations elsewhere (NVEs), neovascularizations at the disc (NVDs), and intraretinal microvascular abnormalities (IRMAs) were scanned by OCTA. The origin and morphology of NVE/NVD/IRMA on OCTA were evaluated. Retinal nonperfusion areas (NPAs) were measured using ImageJ software.
In 35 eyes successfully imaged, 75 NVEs, 35 NVDs, and 12 IRMAs were captured. Three proposed subtypes of NVE were identified based on the origins and morphologic features. Type 1 (32 of 75, 42.67%) originated from the venous side, in a tree-like shape. Type 2 (30 of 75, 40.00%) originated from capillary networks, with an octopus-like appearance. Type 3 (13 of 75, 17.33%) originated from the IRMAs, having a sea fan shape. NVD originated from the retinal artery, from the retinal vein, or from the choroid, and arose from the bending vessels near the rim of the optic disc. IRMA originated from and drained into retinal venules, extending into the retina. The initial layer and affiliated NPA were significantly different in the 3 subtypes of NVEs (all P < .01).
OCTA allowed identification of the origins and morphologic patterns of neovascularization in PDR. The new classification of retinal neovascularization may be useful to better understand pathophysiological mechanisms and to guide efficient therapeutic strategies.
Objectives:
To explore the optical coherence tomography (OCT) biomarkers to predict the transition to chronic central serous chorioretinopathy (cCSC) after retinal laser photocoagulation.
Methods:
...Patients enrolled in this study were from a 12-week clinical trial comparing the efficacy and safety of subthreshold micropulse laser (SML) with threshold conventional laser (TCL) for CSC and had extended follow-up for more than 1 year. They were divided into two groups, transited to cCSC group (cCSC group) and did not transited to cCSC group (non-cCSC group) according to fundus examination at the extended follow-up. Collect the best-corrected visual acuity (BCVA) and OCT characteristics of patients at baseline and 12 weeks after laser treatment.
Results:
Twenty-seven patients were enrolled (42.6 ± 7.7 years old), and duration of follow-up was 178.9 ± 88.8 (57.0–312.0) weeks. Nine patients (33.3%) were assigned to cCSC group, and the other 18 patients (66.7%) were assigned to the non-cCSC group. Twelve weeks after the laser treatment, subretinal fluid (SRF) of 15 patients (83.3%) in non-cCSC group and 5 patients (55.6%) in cCSC group absorbed completely; the height of SRF had statistical difference between two groups (p = 0.035); rough RPE was less common in cCSC group (p = 0.030); hyper reflective mass (HRM) was more common in cCSC group (p = 0.024); more number of hyper reflective foci (HRF) in outer segment of photoreceptor layer were detected in cCSC group (p = 0.035). From baseline to 12 weeks after laser treatment, the number of HRF in outer segment photoreceptor layer did not change significantly in cCSC group (p = 0.665) but decreased significantly in non-cCSC group (p = 0.000). A total of five patients suffered binocular CSC, three of them in the non-cCSC group occurred later than the other two in the cCSC group (129.9–278.3 weeks vs 96.1–114.9 weeks after baseline).
Conclusion:
SRF, rough RPE, HRM, and number of HRF in outer segment photoreceptor layer 12 weeks after laser treatment, and change in the number of HRF in outer segment photoreceptor layer from baseline to 12 weeks after laser treatment may predict the transition to cCSC.
Purpose: To analyze the characteristics of optical coherence tomography in acute macular neuroretinopathy (AMN) following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and ...discuss the prognostic predictors. Methods: Patients with AMN following SARS-CoV-2 infection were divided into two groups according to the presence or absence of hyperreflective outer nuclear layer (ONL) lesion involving the fovea. Results: The first visit included 14 eyes in the fovea-involved group and 20 eyes in the no fovea-involved group. Ellipsoid zone (EZ) hyporeflection and interdigitation zone (IZ) interruption were detected in all eyes. Other common manifestations were myoid zone (MZ) hyperreflection (76.5%), ONL hyperreflection (73.5%), outer plexiform layer (OPL) thickening (64.7%), and EZ interruption (50%). The follow-up period was 48.4 ± 55.3 days. At the last visit, 12 eyes were in the fovea-involved group and 13 eyes in the no fovea-involved group. IZ interruption was detected in all eyes. Other common manifestations were EZ hyporeflection (92.0%), ONL atrophy (40.0%), OPL thickening (36.0%), OPL linear (32.0%), and MZ hyperreflection (32%). The improvement of visual acuity (VA) was -0.5 ± 0.5 and -0.2 ± 0.4 in the fovea-involved group and the no fovea-involved group, respectively, with a statistically significant difference between them ( P = 0.045). Initial VA, initial cotton wool spot, initial ONL cyst, final ONL cyst, and final OPL linear were associated with final VA ( P = 0.000, P = 0.029, P = 0.044, P = 0.049, P = 0.049, respectively). Conclusions: In the early stage of AMN following SARS-CoV-2 infection, IZ interruption and EZ hyporeflection were the most common manifestations, and pathology of IZ was more serious than that of EZ. Subsequently, OPL and ONL atrophied, and ONL atrophied faster. Regardless of whether hyperreflective ONL involved the fovea, VA improved, with a more noticeable improvement found in the fovea-involved group. The presence of initial ONL cyst and initial cotton wool spot, rapid atrophy of OPL, and poorer initial VA indicating poorer VA outcome.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To use optical coherence tomography (OCT) and OCT angiography (OCT-A) to measure changes in the retinal structure and microvasculature of patients with aquaporin-4 antibody-positive, neuromyelitis ...optica spectrum disorder (NMOSD) with a history of optic neuritis (NMOSD+ON) and those without it (NMOSD-ON).
A total of 27 aquaporin-4 antibody-positive NMOSD patients and 31 age- and gender-matched healthy control (HC) participants were included. In 27 NMOSD patients, 19 of them had a history of optic neuritis (ON) and 8 of them had no history of ON. Peripapillary retinal nerve fiber layer (pRNFL) thickness and macular ganglion cell and inner plexiform layer (GCIPL) thickness were measured by OCT. Radial peripapillary capillary density (RPCD) and macular superficial vessel density (MSVD) were measured by OCT-A. Comparisons of retinal structural and microvascular parameters between the cohorts were performed using generalized estimating equation (GEE) models. Diagnostic accuracy was evaluated by the area under the receiver operating characteristics curve (AROC).
In NMOSD+ON eyes, the GCIPL and pRNFL thicknesses, 48.6 ± 7.1 and 61.7 ± 25.1 μm, respectively, were significantly thinner than in HC eyes (
< 0.001 for both). However, in NMOSD-ON eyes, the GCIPL and pRNFL thicknesses were not significantly thinner than in HC eyes (
> 0.05 for both). In NMOSD+ON eyes, the RPCD and MSVD, 37.8 ± 7.1 and 36.7 ± 5.0%, respectively, were significantly less dense than HC eyes (
< 0.001 for both). Similarly, the RPCD and MSVD in NMOSD-ON eyes, 49.0 ± 2.8 and 43.9 ± 4.2%, respectively, were also less dense than in HC eyes (
< 0.029 for RPCD,
< 0.023 for MSVD). The highest AROC, 0.845 (sensitivity = 88.5%, specificity = 78.0%), was achieved by the logistic regression combination of all of the variables, i.e., pRNFL, GCIPL, RPCD, and MSVD.
Retinal microvascular changes were present in NMOSD-ON eyes. The combination of retinal structural and microvascular parameters might be helpful to discriminate NMOSD-ON eyes from HC eyes.
To evaluate the repeatability, reproducibility, and agreement of thickness profile measurements of eight intra-retinal layers determined by an automated algorithm applied to optical coherence ...tomography (OCT) images from two different instruments.
Twenty normal subjects (12 males, 8 females; 24 to 32 years old) were enrolled. Imaging was performed with a custom built ultra-high resolution OCT instrument (UHR-OCT, ∼3 µm resolution) and a commercial RTVue100 OCT (∼5 µm resolution) instrument. An automated algorithm was developed to segment the macular retina into eight layers and quantitate the thickness of each layer. The right eye of each subject was imaged two times by the first examiner using each instrument to assess intra-observer repeatability and once by the second examiner to assess inter-observer reproducibility. The intraclass correlation coefficient (ICC) and coefficients of repeatability and reproducibility (COR) were analyzed to evaluate the reliability.
The ICCs for the intra-observer repeatability and inter-observer reproducibility of both SD-OCT instruments were greater than 0.945 for the total retina and all intra-retinal layers, except the photoreceptor inner segments, which ranged from 0.051 to 0.643, and the outer segments, which ranged from 0.709 to 0.959. The CORs were less than 6.73% for the total retina and all intra-retinal layers. The total retinal thickness measured by the UHR-OCT was significantly thinner than that measured by the RTVue100. However, the ICC for agreement of the thickness profiles between UHR-OCT and RTVue OCT were greater than 0.80 except for the inner segment and outer segment layers.
Thickness measurements of the intra-retinal layers determined by the automated algorithm are reliable when applied to images acquired by the UHR-OCT and RTVue100 instruments.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We report on a real-time acoustic radiation force optical coherence elastography (ARF-OCE) system to map the relative elasticity of corneal tissue. A modulated ARF is used as excitation to vibrate ...the cornea, while OCE serves as detection of tissue response. To show feasibility of detecting mechanical contrast using this method, we performed tissue-equivalent agarose phantom studies with inclusions of a different stiffness. We obtained 3-D elastograms of a healthy cornea and a highly cross-linked cornea. Finally, we induced a stiffness change on a small portion of a cornea and observed the differences in displacement.
SARS-CoV-2 and its mutant strains continue to rapidly spread with high infection and fatality. Large-scale SARS-CoV-2 vaccination provides an important guarantee for effective resistance to existing ...or mutated SARS-CoV-2 virus infection. However, whether the host metabolite levels respond to SARS-CoV-2 vaccine-influenced host immunity remains unclear. To help delineate the serum metabolome profile of SARS-CoV-2 vaccinated volunteers and determine that the metabolites tightly respond to host immune antibodies and cytokines, in this study, a total of 59 sera samples were collected from 30 individuals before SARS-CoV-2 vaccination and from 29 COVID-19 vaccines 2 weeks after the two-dose vaccination. Next, untargeted metabolomics was performed and a distinct metabolic composition was revealed between the pre-vaccination (VB) group and two-dose vaccination (SV) group by partial least squares-discriminant and principal component analyses. Based on the criteria: FDR < 0.05, absolute log2 fold change greater than 0.25, and VIP >1, we found that L-glutamic acid, gamma-aminobutyric acid (GABA), succinic acid, and taurine showed increasing trends from SV to VB. Furthermore, SV-associated metabolites were mainly annotated to butanoate metabolism and glutamate metabolism pathways. Moreover, two metabolite biomarkers classified SV from VB individuals with an area under the curve (AUC) of 0.96. Correlation analysis identified a positive association between four metabolites enriched in glutamate metabolism and serum antibodies in relation to IgG, IgM, and IgA. These results suggest that the contents of gamma-aminobutyric acid and indole in serum could be applied as biomarkers in distinguishing vaccinated volunteers from the unvaccinated. What’s more, metabolites such as GABA and taurine may serve as a metabolic target for adjuvant vaccines to boost the ability of the individuals to improve immunity.
To obtain accurate soil parameters and improve the accuracy of the acoustic-soil discrete element simulation model, we studied the model’s parameter calibration. The simulation test was carried out ...using the measured acoustic velocity and dominant frequency as the response value (index). Firstly, the Plackett—Burman test scheme was used to obtain the sensitivity ranking of soil parameters to the dominant frequency and velocity of the acoustic wave. The parameters that significantly affect the acoustic wave were obtained: Shear modulus, Poisson’s ratio, and coefficient of restitution. Then the Box—Behnken test scheme was used to establish the regression relationship between the dominant frequency and the velocity of the sound wave and Shear modulus, Poisson’s ratio, and Coefficient of restitution. The results shows that the indexes that researchers focus on are different in different scenarios, and the sensitivity of soil parameters to different indicators is different, which results in different soil parameter values after calibration. This study analyzed the main factors affecting the accuracy of the acoustic-discrete element model in constructing the model, provided a method for improving the construction accuracy of the acoustic wave—soil discrete element model and provided a reference for the construction of discrete elements models in other fields.
Abstract
Objectives
To evaluate the efficacy of anti-vascular endothelial growth factor (VEGF) in treatment of age-related macular degeneration (AMD) with retinal pigment epithelial detachment (PED).
...Methods
Systematic review identifying studies comparing intravitreal ranibizumab (IVR), intravitreal aflibercept (IVA) and intravitreal conbercept (IVC) published before Mar 2022.
Results
One randomized controlled trial and 6 observational studies were selected for meta-analysis (1,069 patients). The change of best corrected visual acuity (BCVA) in IVA 2.0 mg group was better than IVR 0.5 mg (average difference 0.07) and IVR 2.0 mg (average difference 0.10), the differences were statistically significant. The change of the height of PED in IVA 2.0 group was better than IVR 0.5 group (average difference 45.30), the difference was statistically significant. The proportion of patients without PED at last visit in IVA 2.0 group were better than those in IVR 2.0 group (hazard ratio 1.91), the difference was statistically significant. There was no significant difference compared with IVR 0.5 group (hazard ratio 1.45). IVA required fewer injections than IVR, with a mean difference of -1.58.
Conclusions
IVA appears to be superior to IVR in improvement of BCVA, height decrease of PED and regression of PED with less injections in nAMD with PED.
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