To evaluate retinal vessel morphology using split-spectrum amplitude-decorrelation angiography with optical coherence tomography in healthy eyes.
Fifty-two eyes of 26 healthy volunteers (age range ...from 35 to 48 years; mean age 41.94 years; SD: ±4.13) were evaluated by optical coherence tomography angiography in the macular region. The protocol acquisition consisted of a 216 × 216 A-scan that was repeated 5 times in the same position, in 3 × 3 mm centered into the fovea.
All 52 eyes showed 2 separate vascular networks in the inner retina: the superficial network, located in the nerve fiber layer and in the ganglion cell layer, and the deep network, detected in the outer plexiform layer. The superficial and deep networks showed interconnections of vertical vessels. The reference planes to observe the 2 networks were defined at 60 μm, with an inner limiting membrane reference (6 μm offset), and 30 μm, with an inner plexiform layer reference (60 μm offset), respectively.
Optical coherence tomography angiography can separately detect the superficial vascular and the deep vascular networks. These networks are overlaid and seem to be fused when seen with standard angiographies. Furthermore, optical coherence tomography angiography technology allows for the visualization of abnormal blood column and vessel wall details.
To assess the longitudinal development of choroidal neovascularization (CNV) Type 2 after intravitreal anti-vascular endothelial growth factor by optical coherence tomography-angiography (OCT-A).
...Five eyes of five patients with naive CNV Type 2 were assessed by OCT-A in this observational longitudinal study. To perform, the OCT-A used an 840-nm wavelength OCT device (XR-Avanti, Freemont; Optovue) based on split-spectrum amplitude-decorrelation angiography algorithm. The timing of analysis was after 24 hours, between 7 days and 10 days, between 12 days and 18 days, and 30 days after the intravitreal anti-vascular endothelial growth factor injections. The protocol of analysis was 3-mm × 3-mm OCT angiograms centered at the macula. The day after the injection, OCT-A showed the decrease of neovascularization, with apparent vessel fragmentation. The CNV area was reduced with pruning of thinner anastomoses and loss of smaller vessels. Decrease of dimensions of CNV area, microvascular rarefaction, and vessels narrowing was observed between 7 days and 10 days, between 12 days and 18 days because of the further loss of smaller capillaries. Residual flow was always visible to the afferent trunk over the time.
The mean age of patients was 72.6 (SD ±16.22) years. All were women, naive cases, and followed from 5 months to 14 months. Over that time, they had a mean number of 5.5 intravitreal injections (from 3 to 8) and a mean number of 11 OCT-A examinations each (from 8 to 26). The most salient result emerging from this study is the consistency in the patterns of cyclic CNV variations after treatment in different patients. This CNV cycle was approximately 62 days long.
This study suggests that OCT-A is able to detect the Type 2 CNV developments. This new method allows noninvasive analysis of CNV networks remodeling during anti-vascular endothelial growth factor follow-up. In conclusion, OCT-A provides a useful approach for monitoring the CNV Type 2 over the time.
To analyze the foveal microvasculature features in eyes with branch retinal vein occlusion (BRVO) using optical coherence tomography angiography based on split spectrum amplitude decorrelation ...angiography technology.
A total of 10 BRVO eyes (mean age 64.2 ± 8.02 range between 52 years and 76 years) were evaluated by optical coherence tomography angiography (XR-Avanti; Optovue). The macular angiography scan protocol covered a 3 mm × 3 mm area. The focus of angiography analysis were two retinal layers: superficial vascular network and deep vascular network. The following vascular morphological congestion parameters were assessed in the vein occlusion area in both the superficial and deep networks: foveal avascular zone enlargement, capillary non-perfusion occurrence, microvascular abnormalities appearance, and vascular congestion signs. Image analyses were performed by 2 masked observers and interobserver agreement of image analyses was 0.90 (κ = 0.225, P < 0.01).
In both superficial and deep network of BRVO, a decrease in capillary density with foveal avascular zone enlargement, capillary non-perfusion occurrence, and microvascular abnormalities appearance was observed (P < 0.01). The deep network showed the main vascular congestion at the boundary between healthy and nonperfused retina.
Optical coherence tomography angiography in BRVO allows to detect foveal avascular zone enlargement, capillary nonperfusion, microvascular abnormalities, and vascular congestion signs both in the superficial and deep capillary network in all eyes. Optical coherence tomography angiography technology is a potential clinical tool for BRVO diagnosis and follow-up, providing stratigraphic vascular details that have not been previously observed by standard fluorescein angiography. The normal retinal vascular nets and areas of nonperfusion and congestion can be identified at various retinal levels. Optical coherence tomography angiography provides noninvasive images of the retinal capillaries and vascular networks.
To use optical coherence tomography (OCT) angiography to monitor the short-term blood flow changes in choroidal neovascularization (CNV) in response to treatment.
In this retrospective report, a case ...of exudative CNV was followed closely with OCT angiography over three cycles of antiangiogenic treatment. Outer retinal flow index, CNV flow area and central macular retinal thickness were measured.
Quantitative measurements of CNV flow area and flow index showed rapid shutdown of flow over the initial 2 weeks, followed by reappearance of CNV channel by the fourth week, preceding fluid reaccumulation at 6 weeks.
Frequent OCT angiography reveals a previously unknown pattern of rapid shutdown and reappearance of CNV channels within treatment cycles. OCT angiographic changes precede fluid reaccumulation and could be useful as leading indicators of CNV activity that could guide treatment timing. Further studies using OCT angiography in short intervals between antiangiogenic treatments are needed.
To evaluate the incidence of neovascularization (NV) secondary to central serous chorioretinopathy (CSC)-a condition belonging to the spectrum of pachychoroid disorders by means of optical coherence ...tomography angiography.
One hundred and seventy five eyes with CSC were evaluated in this retrospective observational study. The eyes with acute or chronic CSC with no NV were included in Group 1, and those with NV were evaluated in Group 2. Only eyes that had undergone structural optical coherence tomography and optical coherence tomography angiography were included. Age, best-corrected visual acuity, and subfoveal choroidal thickness were evaluated in all eyes. In Group 2, the type and morphology of NV and the occurrence of exudation were considered.
Of a total of 175 eyes with CSC, 86 had the acute form and 89 the chronic. Approximately 140 belonged to Group 1 (80%) and 35 to Group 2 (20%). Approximately 39.2% of all patient with chronic CSC developed NV. Mean age in Groups 1 and 2 was 53.3 years (±10.9) and 66.6 years (±10.2), respectively. Mean best-corrected visual acuity in Groups 1 and 2 was 45.7 (±11.7) and 30.9 (±17.9) early treatment diabetic retinopathy study letters, respectively. Mean CCT in Group 1 and 2 was 417.5 µm (±123) and 344.2 µm (±165.9), respectively. In Group 2, all patients had Type 1 NV (100%); 29 eyes (83%) had filamentous feature, and 6 eyes (17%) had irregular shape. Silent nonexudative NV was observed in 7 eyes (20%), all belonging to Group 2.
The use of optical coherence tomography angiography in everyday clinical practice allows for the accurate analysis of the chorioretinal vascular setting, with the identification of new vessels that could remain misdiagnosed.
Optovue AngioVue system technology for optical coherence tomography (OCT) angiography is based on the AngioVue Imaging System (Optovue, Inc., Freemont, CA), using split-spectrum ...amplitude-decorrelation angiography (SSADA) algorithm. This algorithm was developed to minimize scanning time. It detects motion in blood vessel lumen by measuring the variation in reflected OCT signal amplitude between consecutive cross-sectional scans. The novelty of SSADA lies in how the OCT signal is processed to enhance flow detection and reject axial bulk motion noise. Specifically, the algorithm splits the OCT image into different spectral bands, thus increasing the number of usable image frames. Each new frame has a lower axial resolution that is less susceptible to axial eye motion caused by blood pulsation. Optovue AngioVue system technology allows quantitative analysis. It provides numerical data about flow area and non-flow area. It can also generate a flow density map. These metrics may serve as biomarkers in diagnosis and for tracking disease progression or treatment response. Flow area: the software will calculate the drawn area and vessel area in mm(2). It allows for comparison of all measurements for a given participant. Non-flow area: the software shows the non-perfused areas by mouse click selection. Ischemic areas will be shown in yellow. These areas may be saved and matched with others in the study. Flow density tool is able to measure the percentage of vascular areas on en face angiograms. This analysis is based on an ETDRS grid centered on the macula as with the thickness map. This tool works both on inner and outer vascular plexus.
We report successful surgical management of post-intubation tracheoesophageal fistula (TEF) in an adult patient requiring long-term mechanical ventilation. A complete tracheal transection without ...tracheal resection, via an anterior cervical approach, followed by direct closure of tracheal and esophageal defect, and interposition of muscle flap between the suture lines and tracheal reconstruction was performed. In selected cases, this surgical procedure may be a viable alternative to traditional techniques used to treat post-intubation TEF via the anterior or lateral cervical approach.
Purpose To characterize perifoveal intraretinal cavities observed around full-thickness macular holes (MH) using en face optical coherence tomography and to establish correlations with histology of ...human and primate maculae. Design Retrospective nonconsecutive observational case series. Methods Macular en face scans of 8 patients with MH were analyzed to quantify the areas of hyporeflective spaces, and were compared with macular flat mounts and sections from 1 normal human donor eye and 2 normal primate eyes ( Macaca fascicularis ). Immunohistochemistry was used to study the distribution of glutamine synthetase, expressed by Müller cells, and zonula occludens-1, a tight-junction protein. Results The mean area of hyporeflective spaces was lower in the inner nuclear layer (INL) than in the complex formed by the outer plexiform (OPL) and the Henle fiber layers (HFL): 5.0 × 10−3 mm2 vs 15.9 × 10−3 mm2 , respectively ( P < .0001, Kruskal-Wallis test). In the OPL and HFL, cavities were elongated with a stellate pattern, whereas in the INL they were rounded and formed vertical cylinders. Immunohistochemistry confirmed that Müller cells followed a radial distribution around the fovea in the frontal plane and a “Z-shaped” course in the axial plane, running obliquely in the OPL and HFL and vertically in the inner layers. In addition, zonula occludens-1 co-localized with Müller cells within the complex of OPL and HFL, indicating junctions in between Müller cells and cone axons. Conclusion The dual profile of cavities around MHs correlates with Müller cell morphology and is consistent with the hypothesis of intra- or extracellular fluid accumulation along these cells.
Dear Editor,
we have read with interest the case reported by Rotolo et al. (published in February 2023 as Early Access) concerning the surgical management of tracheoesophageal fistula (TEF) in a ...COVID-19 patient treated with prolonged mechanical ventilation for severe respiratory failure.
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