The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Richard F Spaide - One of the best experts on this subject based on the ideXlab platform.
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evaluation of segmentation of the superficial and deep Vascular layers of the retina by optical coherence tomography angiography instruments in normal eyes
JAMA Ophthalmology, 2017Co-Authors: Richard F Spaide, Christine A CurcioAbstract:Importance Correct attribution of Vascular features in optical coherence tomography (OCT) angiography depends on accurate segmentation of retinal layers. Objective To evaluate the segmentation of retinal layers among 3 OCT angiography instruments in the central macula, an area where the superficial and deep Vascular Plexuses terminate. Design, Setting, and Participants A retrospective review of a representative OCT angiogram from 1 patient and an evaluation of the Vascular pattern in an autopsied eye were conducted at a community retina practice at a university laboratory. A set of 3 × 3-mm scans centered on the fovea using the Cirrus 5000, RTVue XR Avanti, and Triton DRI OCT platforms with default layer segmentations were used to evaluate segmentation accuracy of a normal macula of a white man in his 60s as an emblematic example. A representative histologic section from the central macula of a normal eye was used as an exemplar. Main Outcomes and Measures Retinal layer segmentation and resultant Vascular image compared with vessels as seen in histologic section. Results The segmentation slab designed to isolate the superficial Vascular Plexus included the deep Vascular Plexus in the central macula for all 3 instruments. None of the instruments produced segmented regions that followed the relevant anatomic layers correctly. Conclusions and Relevance Because of inherent errors in segmentation, studies of the superficial and deep Vascular Plexuses using manufacturer-recommended default settings are likely to be biased. A proposal for an improved segmentation strategy is presented.
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retinal Vascular cystoid macular edema review and new theory
Retina-the Journal of Retinal and Vitreous Diseases, 2016Co-Authors: Richard F SpaideAbstract:: Retinal Vascular disease has the potential to affect hundreds of millions of people, with the inherent risk of vision loss related to cystoid macular edema. Although there have been histologic evaluation of eyes having cystoid macular edema, the most recent paper was published more than 30 years ago. In retinal Vascular cystoid macular edema fluorescein angiography, a modality that images the superficial Vascular Plexus, shows increased leakage. Optical coherence tomography angiography has provided unprecedented resolution of retinal Vascular flow in a depth resolved manner and demonstrates areas of decreased or absent flow in the deep Vascular Plexus colocalizing with the cystoid spaces. There has been a large amount of research on fluid management and edema in the brain, much of which may have analogues in the eye. Interstitial flow of fluid as managed by Muller cells may occur in the retina, comparable in some ways to the bulk flow in brain parenchyma, which is managed by astrocytes. Absent blood flow in the deep retinal Plexus may restrict fluid management strategies in the retina, to include transport of excess fluid out of the retina into the blood by Muller cells. Application of this theory may help in increasing understanding of the pathophysiology of retinal Vascular cystoid macular edema and may lead to new therapeutic approaches.
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volume rendering optical coherence tomography angiography of macular telangiectasia type 2
Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J Cooney, Lawrence A Yannuzzi, Chandrakumar Balaratnasingam, Kunal K Dansingani, Mihoko SuzukiAbstract:Purpose To evaluate the Vascular structure of eyes with macular telangiectasia type 2 (MacTel2) using volume-rendered optical coherence tomography angiography (OCTA). Design Retrospective cross-sectional study. Participants A total of 14 consecutive patients (20 eyes) with MacTel2 who had a signal strength score ≥55 and could maintain fixation during the scan process. Methods The eyes were scanned using optical coherence tomography with split-spectrum amplitude decorrelation techniques to derive flow information. Data were extracted and used to create volume-rendered images of the retinal vasculature that could be rotated about 3 different axes for evaluation. Main Outcome Measures Descriptive appraisal of the Vascular abnormalities associated with MacTel2. Results Vessels posterior to the outer boundary of the deep retinal Plexus were secondary to retinal thinning, Vascular invasion, or a combination of both. These vessels had the same shape and distribution as the late staining seen during conventional fluorescein angiography. Lateral contraction in the temporal macula in 5 eyes created an appearance of vessels radiating from a central locus, which was the site of a right angle vein. Loss of macular tissue as part of the disease process led to a central amalgamation of the inner Vascular Plexus and the deep Vascular Plexus, which appeared to be in a state of decline. Subretinal neoVascularization originated from the retinal circulation but involved not only the subretinal space but also could infiltrate the remaining, thinned, retina. Conclusions Volume rendering of OCTA information preserves the 3-dimensional relationships among retinal Vascular layers and provides opportunities to visualize retinal Vascular abnormalities in unprecedented detail. The retinal Vascular leakage and invasion in MacTel2 may arise as a consequence of loss of control with depletion of Muller cells and exposure of the remaining retinal vessels to the more hypoxic environment near the inner segments of the photoreceptors.
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retinal Vascular layers in macular telangiectasia type 2 imaged by optical coherence tomographic angiography
JAMA Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J CooneyAbstract:IMPORTANCE Macular telangiectasia type 2 (MacTel 2) is a rare disease in which abnormalities of the retinal vasculature play a key role. The Vascular abnormalities are typically evaluated using fluorescein angiography, a modality with known defects in imaging the deeper layers of the retinal vasculature. Angiography based on optical coherence tomography can image vessels based on flow characteristics without dye injection and may provide improved information concerning the pathophysiology of MacTel 2. OBJECTIVE To investigate MacTel 2 using optical coherence tomographic angiography. DESIGN, SETTING, AND PARTICIPANTS Fourteen eyes of 7 patients with MacTel 2 were analyzed in a community-based retina practice. The flow imaging was based on split-spectrum amplitude decorrelation angiography, which can dissect layers of vessels in the retina. The inner retinal Vascular Plexus, the outer Plexus, and deeper Vascular invasion into the outer and subretinal spaces were optically dissected in en face images based on flow. MAIN OUTCOMES AND MEASURES Visualization and qualitative evaluation of the Vascular layers of the retina as they may be affected by MacTel 2, both in terms of depth and topographic characteristics. RESULTS A consistent set of retinal Vascular changes were seen in the eyes with MacTel 2. There was some loss of capillary density in the inner retinal Vascular Plexus but many more prominent alterations in the deep retinal Vascular Plexus. In milder forms of the disease, the deep Plexus showed dilation and telangiectasis and, in more advanced cases, thinning and loss. The remaining vessels were elongated and widely spaced capillary segments. Invasion by new vessels into the outer and subretinal spaces occurred subjacent to the regions showing greatest flow imaging abnormalities in the inner and deep retinal Vascular layers. CONCLUSIONS AND RELEVANCE As evidenced by the patients in this study, important retinal Vascular changes in MacTel 2 occur in the deep capillary Plexus of the retina, a layer poorly visualized by fluorescein angiography and, to a lesser extent, in the inner Vascular Plexus. The proliferation of vessels in the outer and subretinal spaces may be in part compensatory for poor retinal perfusion by established Vascular layers in the retina.
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retinal Vascular layers imaged by fluorescein angiography and optical coherence tomography angiography
JAMA Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J CooneyAbstract:Importance The retinal vasculature is involved in many ocular diseases that cause visual loss. Although fluorescein angiography is the criterion standard for evaluating the retina vasculature, it has risks of adverse effects and known defects in imaging all the layers of the retinal vasculature. Optical coherence tomography (OCT) angiography can image vessels based on flow characteristics and may provide improved information. Objective To investigate the ability of OCT angiography to image the Vascular layers within the retina compared with conventional fluorescein angiography. Design, Setting, and Participants In this study, performed from March 14, 2014, through June 24, 2014, a total of 5 consecutive, overlapping B-scan OCT angiography images composed of 216 A-scans were obtained at 216 discrete positions within a region of interest, typically a 2 × 2-mm area of the retina. The flow imaging was based on split-spectrum amplitude decorrelation angiography (SSADA), which can dissect layers of vessels in the retina. These distinct layers were compared with the fluorescein angiograms in 12 healthy eyes from patients at a private practice retina clinic to evaluate the ability to visualize the radial peripapillary capillary network. The proportion of the inner vs outer retinal Vascular layers was estimated by 3 masked readers and compared with conventional fluorescein angiograms of the same eyes. Main Outcomes and Measures Outcome measures were visualization of the radial peripapillary capillary network in the fluorescein and SSADA scans and the proportion of the inner retinal Vascular Plexus vs the outer retinal capillary Plexus as seen in SSADA scans that would match the fluorescein angiogram. Results In none of the 12 eyes could the radial peripapillary capillary network be visualized completely around the nerve head by fluorescein angiography, whereas the network was readily visualized in the SSADA scans. The fluorescein angiograms were matched, with a mean proportion of the inner Vascular Plexus being 95.3% (95% CI, 92.2%-97.8%) vs 4.7% (95% CI, 2.6%-5.7%) for the outer capillary Plexus from the SSADA scans. Conclusions and Relevance Fluorescein angiography does not image the radial peripapillary or the deep capillary networks well. However, OCT angiography can image all layers of the retinal vasculature without dye injection. Therefore, OCT angiography, and the findings generated, have the potential to affect clinical evaluation of the retina in healthy patients and patients with disease.
Michael J Cooney - One of the best experts on this subject based on the ideXlab platform.
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volume rendering optical coherence tomography angiography of macular telangiectasia type 2
Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J Cooney, Lawrence A Yannuzzi, Chandrakumar Balaratnasingam, Kunal K Dansingani, Mihoko SuzukiAbstract:Purpose To evaluate the Vascular structure of eyes with macular telangiectasia type 2 (MacTel2) using volume-rendered optical coherence tomography angiography (OCTA). Design Retrospective cross-sectional study. Participants A total of 14 consecutive patients (20 eyes) with MacTel2 who had a signal strength score ≥55 and could maintain fixation during the scan process. Methods The eyes were scanned using optical coherence tomography with split-spectrum amplitude decorrelation techniques to derive flow information. Data were extracted and used to create volume-rendered images of the retinal vasculature that could be rotated about 3 different axes for evaluation. Main Outcome Measures Descriptive appraisal of the Vascular abnormalities associated with MacTel2. Results Vessels posterior to the outer boundary of the deep retinal Plexus were secondary to retinal thinning, Vascular invasion, or a combination of both. These vessels had the same shape and distribution as the late staining seen during conventional fluorescein angiography. Lateral contraction in the temporal macula in 5 eyes created an appearance of vessels radiating from a central locus, which was the site of a right angle vein. Loss of macular tissue as part of the disease process led to a central amalgamation of the inner Vascular Plexus and the deep Vascular Plexus, which appeared to be in a state of decline. Subretinal neoVascularization originated from the retinal circulation but involved not only the subretinal space but also could infiltrate the remaining, thinned, retina. Conclusions Volume rendering of OCTA information preserves the 3-dimensional relationships among retinal Vascular layers and provides opportunities to visualize retinal Vascular abnormalities in unprecedented detail. The retinal Vascular leakage and invasion in MacTel2 may arise as a consequence of loss of control with depletion of Muller cells and exposure of the remaining retinal vessels to the more hypoxic environment near the inner segments of the photoreceptors.
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retinal Vascular layers in macular telangiectasia type 2 imaged by optical coherence tomographic angiography
JAMA Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J CooneyAbstract:IMPORTANCE Macular telangiectasia type 2 (MacTel 2) is a rare disease in which abnormalities of the retinal vasculature play a key role. The Vascular abnormalities are typically evaluated using fluorescein angiography, a modality with known defects in imaging the deeper layers of the retinal vasculature. Angiography based on optical coherence tomography can image vessels based on flow characteristics without dye injection and may provide improved information concerning the pathophysiology of MacTel 2. OBJECTIVE To investigate MacTel 2 using optical coherence tomographic angiography. DESIGN, SETTING, AND PARTICIPANTS Fourteen eyes of 7 patients with MacTel 2 were analyzed in a community-based retina practice. The flow imaging was based on split-spectrum amplitude decorrelation angiography, which can dissect layers of vessels in the retina. The inner retinal Vascular Plexus, the outer Plexus, and deeper Vascular invasion into the outer and subretinal spaces were optically dissected in en face images based on flow. MAIN OUTCOMES AND MEASURES Visualization and qualitative evaluation of the Vascular layers of the retina as they may be affected by MacTel 2, both in terms of depth and topographic characteristics. RESULTS A consistent set of retinal Vascular changes were seen in the eyes with MacTel 2. There was some loss of capillary density in the inner retinal Vascular Plexus but many more prominent alterations in the deep retinal Vascular Plexus. In milder forms of the disease, the deep Plexus showed dilation and telangiectasis and, in more advanced cases, thinning and loss. The remaining vessels were elongated and widely spaced capillary segments. Invasion by new vessels into the outer and subretinal spaces occurred subjacent to the regions showing greatest flow imaging abnormalities in the inner and deep retinal Vascular layers. CONCLUSIONS AND RELEVANCE As evidenced by the patients in this study, important retinal Vascular changes in MacTel 2 occur in the deep capillary Plexus of the retina, a layer poorly visualized by fluorescein angiography and, to a lesser extent, in the inner Vascular Plexus. The proliferation of vessels in the outer and subretinal spaces may be in part compensatory for poor retinal perfusion by established Vascular layers in the retina.
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retinal Vascular layers imaged by fluorescein angiography and optical coherence tomography angiography
JAMA Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J CooneyAbstract:Importance The retinal vasculature is involved in many ocular diseases that cause visual loss. Although fluorescein angiography is the criterion standard for evaluating the retina vasculature, it has risks of adverse effects and known defects in imaging all the layers of the retinal vasculature. Optical coherence tomography (OCT) angiography can image vessels based on flow characteristics and may provide improved information. Objective To investigate the ability of OCT angiography to image the Vascular layers within the retina compared with conventional fluorescein angiography. Design, Setting, and Participants In this study, performed from March 14, 2014, through June 24, 2014, a total of 5 consecutive, overlapping B-scan OCT angiography images composed of 216 A-scans were obtained at 216 discrete positions within a region of interest, typically a 2 × 2-mm area of the retina. The flow imaging was based on split-spectrum amplitude decorrelation angiography (SSADA), which can dissect layers of vessels in the retina. These distinct layers were compared with the fluorescein angiograms in 12 healthy eyes from patients at a private practice retina clinic to evaluate the ability to visualize the radial peripapillary capillary network. The proportion of the inner vs outer retinal Vascular layers was estimated by 3 masked readers and compared with conventional fluorescein angiograms of the same eyes. Main Outcomes and Measures Outcome measures were visualization of the radial peripapillary capillary network in the fluorescein and SSADA scans and the proportion of the inner retinal Vascular Plexus vs the outer retinal capillary Plexus as seen in SSADA scans that would match the fluorescein angiogram. Results In none of the 12 eyes could the radial peripapillary capillary network be visualized completely around the nerve head by fluorescein angiography, whereas the network was readily visualized in the SSADA scans. The fluorescein angiograms were matched, with a mean proportion of the inner Vascular Plexus being 95.3% (95% CI, 92.2%-97.8%) vs 4.7% (95% CI, 2.6%-5.7%) for the outer capillary Plexus from the SSADA scans. Conclusions and Relevance Fluorescein angiography does not image the radial peripapillary or the deep capillary networks well. However, OCT angiography can image all layers of the retinal vasculature without dye injection. Therefore, OCT angiography, and the findings generated, have the potential to affect clinical evaluation of the retina in healthy patients and patients with disease.
A Gaudric - One of the best experts on this subject based on the ideXlab platform.
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vessel density of superficial intermediate and deep capillary Plexuses using optical coherence tomography angiography
Retina-the Journal of Retinal and Vitreous Diseases, 2019Co-Authors: Carlo Lavia, Sophie Bonnin, Milena Maule, Ali Erginay, Ramin Tadayoni, A GaudricAbstract:PURPOSE To provide values of retinal vessel density (VD) in the three retinal capillary Plexuses, foveal aVascular zone (FAZ) area, and retinal layer thickness in a cohort of healthy subjects. METHODS The optical coherence tomography angiography maps of 148 eyes of 84 healthy subjects, aged 22 to 76 years, were analyzed for measuring VD of the retinal capillary Plexuses, using the Optovue device comprising a projection artifact removal algorithm. Foveal aVascular zone metrics were measured, and the relationship between optical coherence tomography angiography findings and age, sex, and image quality was studied. RESULTS The deep capillary Plexus showed the lowest VD (31.6% ± 4.4%) in all macular areas and age groups compared with the superficial Vascular Plexus (47.8% ± 2.8%) and intermediate capillary Plexus (45.4% ± 4.2%). The mean VD decreased by 0.06%, 0.06%, and 0.08% per year, respectively, in the superficial Vascular Plexus, intermediate capillary Plexus, and deep capillary Plexus. Mean FAZ area, FAZ acircularity index, and capillary density in a 300-µm area around the FAZ were 0.25 ± 0.1 mm, 1.1 ± 0.05, and 50.8 ± 3.4%, respectively. The yearly increase in FAZ area was 0.003 mm (P < 0.001). CONCLUSION The deep capillary Plexus, a single monoplanar capillary Plexus located in the outer plexiform layer, has the lowest VD, a significant finding that might be used to evaluate retinal Vascular diseases. Vascular density decreased with age in the three capillary Plexuses.
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new insight into the macular deep Vascular Plexus imaged by optical coherence tomography angiography
Retina-the Journal of Retinal and Vitreous Diseases, 2015Co-Authors: Sophie Bonnin, Ramin Tadayoni, Valerie Mane, Aude Couturier, Morgane Julien, Michel Paques, A GaudricAbstract:To describe the macular deep capillary Plexus (DCP) in normal eyes using optical coherence tomography angiography.Retrospective study including 41 consecutive normal eyes imaged using optical coherence tomography angiography (RTVue XR Avanti; Optovue Inc). Default autosegmentation of the superficial capillary Plexus (SCP) and DCP, and manual adjustments of "deep settings" were used to analyze the organization of the normal macular microVascularization and to investigate in vivo the connection between these capillary networks.Mean age was 31 years (range, 22-55 years). The SCP and DCP had 2 different organizations, but the Plexus autosegmentation was imperfect: In 68% of cases, the image of the SCP variably superimposed on the DCP, interfering with its analysis. The SCP was composed on average of 7 pairs of arterioles and venules obvious on each 3-mm × 3-mm optical coherence tomography angiography scanning area. The DCP was composed of a capillary vortex arrangement, whose centers were aligned along the course of the macular superficial venules.The SCP and DCP had two different topographic organizations. The pattern of the capillary units converging into capillary vortexes highly suggests that they drain into the superficial venules. The different structural properties of the SCP and DCP could explain the differences in flow resistance and perfusion.
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new insight into the macular deep Vascular Plexus imaged by optical coherence tomography angiography
Retina-the Journal of Retinal and Vitreous Diseases, 2015Co-Authors: Sophie Bonnin, Ramin Tadayoni, Valerie Mane, Aude Couturier, Morgane Julien, Michel Paques, A GaudricAbstract:Purpose To describe the macular deep capillary Plexus (DCP) in normal eyes using optical coherence tomography angiography. Methods Retrospective study including 41 consecutive normal eyes imaged using optical coherence tomography angiography (RTVue XR Avanti; Optovue Inc). Default autosegmentation of the superficial capillary Plexus (SCP) and DCP, and manual adjustments of "deep settings" were used to analyze the organization of the normal macular microVascularization and to investigate in vivo the connection between these capillary networks. Results Mean age was 31 years (range, 22-55 years). The SCP and DCP had 2 different organizations, but the Plexus autosegmentation was imperfect: In 68% of cases, the image of the SCP variably superimposed on the DCP, interfering with its analysis. The SCP was composed on average of 7 pairs of arterioles and venules obvious on each 3-mm × 3-mm optical coherence tomography angiography scanning area. The DCP was composed of a capillary vortex arrangement, whose centers were aligned along the course of the macular superficial venules. Conclusion The SCP and DCP had two different topographic organizations. The pattern of the capillary units converging into capillary vortexes highly suggests that they drain into the superficial venules. The different structural properties of the SCP and DCP could explain the differences in flow resistance and perfusion.
Sanna Op Den Dries - One of the best experts on this subject based on the ideXlab platform.
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injury to peribiliary glands and Vascular Plexus before liver transplantation predicts formation of non anastomotic biliary strictures
Journal of Hepatology, 2014Co-Authors: Sanna Op Den Dries, Andrie C Westerkamp, Negin Karimian, Annette S H Gouw, Bote G Bruinsma, James F Markmann, Ton Lisman, Korkut Uygun, Paulo N A MartinsAbstract:Background & Aims The peribiliary glands of large bile ducts have been identified as a niche of progenitor cells that contribute to regeneration of biliary epithelium after injury. We aimed to determine whether injury to the peribiliary glands of donor livers is a risk factor for development of non-anastomotic biliary strictures (NAS) after liver transplantation. Methods In 128 liver transplant procedures, biopsies were taken from the donor bile duct and injury was assessed using an established histological grading system. Histological severity of injury was subsequently compared in liver grafts that later developed biliary structures vs. uncomplicated liver grafts. Results Luminal biliary epithelial loss >50% was observed in 91.8% of the grafts before transplantation, yet NAS occurred in only 16.4%. Periluminal peribiliary glands were more severely injured than deep peribiliary glands located near the fibromuscular layer (>50% loss in 56.9% vs. 17.5%, respectively; p 50% loss in 50.0% vs. 9.8%, respectively; p =0.004). In parallel, injury of the peribiliary Vascular Plexus was more severe in livers that developed NAS, compared to grafts without NAS (>50% Vascular changes in 57.1% vs. 20.3%; p =0.006). Conclusion Injury of peribiliary glands and Vascular Plexus before transplantation is strongly associated with the occurrence of biliary strictures after transplantation. This suggests that insufficient regeneration due to loss of peribiliary glands or impaired blood supply may explain the development of biliary strictures.
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hypothermic oxygenated machine perfusion prevents arteriolonecrosis of the peribiliary Plexus in pig livers donated after circulatory death
PLOS ONE, 2014Co-Authors: Sanna Op Den Dries, Negin Karimian, Annette S H Gouw, Ton Lisman, Michael E Sutton, Marieke T De Boer, Janneke Wiersemabuist, Henri G D Leuvenink, Robert J PorteAbstract:Background: Livers derived from donation after circulatory death (DCD) are increasingly accepted for transplantation. However, DCD livers suffer additional donor warm ischemia, leading to biliary injury and more biliary complications after transplantation. It is unknown whether oxygenated machine perfusion results in better preservation of biliary epithelium and the peribiliary vasculature. We compared oxygenated hypothermic machine perfusion (HMP) with static cold storage (SCS) in a porcine DCD model. Methods: After 30 min of cardiac arrest, livers were perfused in situ with HTK solution (4 degrees C) and preserved for 4 h by either SCS (n = 9) or oxygenated HMP (10 degrees C; n = 9), using pressure-controlled arterial and portal venous perfusion. To simulate transplantation, livers were reperfused ex vivo at 37 degrees C with oxygenated autologous blood. Bile duct injury and function were determined by biochemical and molecular markers, and a systematic histological scoring system. Results: After reperfusion, arterial flow was higher in the HMP group, compared to SCS (251 +/- 28 vs 166 +/- 28 mL/min, respectively, after 1 hour of reperfusion; p = 0.003). Release of hepatocellular enzymes was significantly higher in the SCS group. Markers of biliary epithelial injury (biliary LDH, gamma-GT) and function (biliary pH and bicarbonate, and biliary transporter expression) were similar in the two groups. However, histology of bile ducts revealed significantly less arteriolonecrosis of the peribiliary Vascular Plexus in HMP preserved livers (>50% arteriolonecrosis was observed in 7 bile ducts of the SCS preserved livers versus only 1 bile duct of the HMP preserved livers; p = 0.024). Conclusions: Oxygenated HMP prevents arteriolonecrosis of the peribiliary Vascular Plexus of the bile ducts of DCD pig livers and results in higher arterial flow after reperfusion. Together this may contribute to better perfusion of the bile ducts, providing a potential advantage in the post-ischemic recovery of bile ducts.
James M Klancnik - One of the best experts on this subject based on the ideXlab platform.
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volume rendering optical coherence tomography angiography of macular telangiectasia type 2
Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J Cooney, Lawrence A Yannuzzi, Chandrakumar Balaratnasingam, Kunal K Dansingani, Mihoko SuzukiAbstract:Purpose To evaluate the Vascular structure of eyes with macular telangiectasia type 2 (MacTel2) using volume-rendered optical coherence tomography angiography (OCTA). Design Retrospective cross-sectional study. Participants A total of 14 consecutive patients (20 eyes) with MacTel2 who had a signal strength score ≥55 and could maintain fixation during the scan process. Methods The eyes were scanned using optical coherence tomography with split-spectrum amplitude decorrelation techniques to derive flow information. Data were extracted and used to create volume-rendered images of the retinal vasculature that could be rotated about 3 different axes for evaluation. Main Outcome Measures Descriptive appraisal of the Vascular abnormalities associated with MacTel2. Results Vessels posterior to the outer boundary of the deep retinal Plexus were secondary to retinal thinning, Vascular invasion, or a combination of both. These vessels had the same shape and distribution as the late staining seen during conventional fluorescein angiography. Lateral contraction in the temporal macula in 5 eyes created an appearance of vessels radiating from a central locus, which was the site of a right angle vein. Loss of macular tissue as part of the disease process led to a central amalgamation of the inner Vascular Plexus and the deep Vascular Plexus, which appeared to be in a state of decline. Subretinal neoVascularization originated from the retinal circulation but involved not only the subretinal space but also could infiltrate the remaining, thinned, retina. Conclusions Volume rendering of OCTA information preserves the 3-dimensional relationships among retinal Vascular layers and provides opportunities to visualize retinal Vascular abnormalities in unprecedented detail. The retinal Vascular leakage and invasion in MacTel2 may arise as a consequence of loss of control with depletion of Muller cells and exposure of the remaining retinal vessels to the more hypoxic environment near the inner segments of the photoreceptors.
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retinal Vascular layers in macular telangiectasia type 2 imaged by optical coherence tomographic angiography
JAMA Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J CooneyAbstract:IMPORTANCE Macular telangiectasia type 2 (MacTel 2) is a rare disease in which abnormalities of the retinal vasculature play a key role. The Vascular abnormalities are typically evaluated using fluorescein angiography, a modality with known defects in imaging the deeper layers of the retinal vasculature. Angiography based on optical coherence tomography can image vessels based on flow characteristics without dye injection and may provide improved information concerning the pathophysiology of MacTel 2. OBJECTIVE To investigate MacTel 2 using optical coherence tomographic angiography. DESIGN, SETTING, AND PARTICIPANTS Fourteen eyes of 7 patients with MacTel 2 were analyzed in a community-based retina practice. The flow imaging was based on split-spectrum amplitude decorrelation angiography, which can dissect layers of vessels in the retina. The inner retinal Vascular Plexus, the outer Plexus, and deeper Vascular invasion into the outer and subretinal spaces were optically dissected in en face images based on flow. MAIN OUTCOMES AND MEASURES Visualization and qualitative evaluation of the Vascular layers of the retina as they may be affected by MacTel 2, both in terms of depth and topographic characteristics. RESULTS A consistent set of retinal Vascular changes were seen in the eyes with MacTel 2. There was some loss of capillary density in the inner retinal Vascular Plexus but many more prominent alterations in the deep retinal Vascular Plexus. In milder forms of the disease, the deep Plexus showed dilation and telangiectasis and, in more advanced cases, thinning and loss. The remaining vessels were elongated and widely spaced capillary segments. Invasion by new vessels into the outer and subretinal spaces occurred subjacent to the regions showing greatest flow imaging abnormalities in the inner and deep retinal Vascular layers. CONCLUSIONS AND RELEVANCE As evidenced by the patients in this study, important retinal Vascular changes in MacTel 2 occur in the deep capillary Plexus of the retina, a layer poorly visualized by fluorescein angiography and, to a lesser extent, in the inner Vascular Plexus. The proliferation of vessels in the outer and subretinal spaces may be in part compensatory for poor retinal perfusion by established Vascular layers in the retina.
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retinal Vascular layers imaged by fluorescein angiography and optical coherence tomography angiography
JAMA Ophthalmology, 2015Co-Authors: Richard F Spaide, James M Klancnik, Michael J CooneyAbstract:Importance The retinal vasculature is involved in many ocular diseases that cause visual loss. Although fluorescein angiography is the criterion standard for evaluating the retina vasculature, it has risks of adverse effects and known defects in imaging all the layers of the retinal vasculature. Optical coherence tomography (OCT) angiography can image vessels based on flow characteristics and may provide improved information. Objective To investigate the ability of OCT angiography to image the Vascular layers within the retina compared with conventional fluorescein angiography. Design, Setting, and Participants In this study, performed from March 14, 2014, through June 24, 2014, a total of 5 consecutive, overlapping B-scan OCT angiography images composed of 216 A-scans were obtained at 216 discrete positions within a region of interest, typically a 2 × 2-mm area of the retina. The flow imaging was based on split-spectrum amplitude decorrelation angiography (SSADA), which can dissect layers of vessels in the retina. These distinct layers were compared with the fluorescein angiograms in 12 healthy eyes from patients at a private practice retina clinic to evaluate the ability to visualize the radial peripapillary capillary network. The proportion of the inner vs outer retinal Vascular layers was estimated by 3 masked readers and compared with conventional fluorescein angiograms of the same eyes. Main Outcomes and Measures Outcome measures were visualization of the radial peripapillary capillary network in the fluorescein and SSADA scans and the proportion of the inner retinal Vascular Plexus vs the outer retinal capillary Plexus as seen in SSADA scans that would match the fluorescein angiogram. Results In none of the 12 eyes could the radial peripapillary capillary network be visualized completely around the nerve head by fluorescein angiography, whereas the network was readily visualized in the SSADA scans. The fluorescein angiograms were matched, with a mean proportion of the inner Vascular Plexus being 95.3% (95% CI, 92.2%-97.8%) vs 4.7% (95% CI, 2.6%-5.7%) for the outer capillary Plexus from the SSADA scans. Conclusions and Relevance Fluorescein angiography does not image the radial peripapillary or the deep capillary networks well. However, OCT angiography can image all layers of the retinal vasculature without dye injection. Therefore, OCT angiography, and the findings generated, have the potential to affect clinical evaluation of the retina in healthy patients and patients with disease.
