scholarly journals Schlemm’s Canal and Trabecular Meshwork in Eyes with Primary Open Angle Glaucoma: A Comparative Study Using High-Frequency Ultrasound Biomicroscopy

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0145824 ◽  
Author(s):  
Xiaoqin Yan ◽  
Mu Li ◽  
Zhiqi Chen ◽  
Ying Zhu ◽  
Yinwei Song ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yogapriya Sundaresan ◽  
Lakshmi Priya Manivannan ◽  
Shanthi Radhakrishnan ◽  
Krishnadas Subbiah Ramasamy ◽  
Muthukkaruppan Veerappan ◽  
...  

AbstractWe previously identified and characterized human trabecular meshwork stem cells (TMSCs) based on high expression of ABCG2/p75 positivity and high nucleus to cytoplasmic ratio. These TMSCs expressing high ABCG2 and p75 were located to the insert region of the human TM. Additionally, we demonstrated an age-related reduction in the TMSC content which was significantly associated with TM cell loss. In continuation, this study was aimed to determine the TMSC content in glaucomatous donor eyes wherein a drastic reduction in TM cellularity has already been reported. Anterior segments from known glaucomatous (n = 6) and age-matched normal (n = 8) donors were dissected into four quadrants. A minimum of three sections from each quadrant were used for histopathological analysis as well as immunostaining. Analysis of hematoxylin and eosin-stained sections from glaucomatous tissues revealed a decrease in total TM cellularity, thickening of trabecular beams, fusion of trabeculae, absence of patent Schlemm’s canal compared to age-matched controls. In addition, the TM thickness at various positions of the meshwork and the coronal as well as the meridional diameters of the Schlemm’s canal were observed to be significantly reduced in glaucomatous eyes. Further, sections from both the groups were immunostained for universal stem cell marker ABCG2 and neural crest derived stem cell marker p75. The images were acquired using Leica SP8 confocal microscope. Quantification of total TM cellularity based on nuclear counterstain (mean ± SD) using ImageJ identified 69.33 ± 12.77 cells/section in control eyes. In glaucomatous donors, the TM cellularity was found to be reduced significantly to 41.83 ± 9.0 (p = 0.0007). In addition, a reduction in the percentage of TMSCs (cells with high ABCG2 expression and p75 positivity) was evident in glaucomatous donors (0.14 ± 0.17%) compared to age-matched controls (4.73 ± 5.46%) (p = 0.064). Thus, the present study confirmed the significant decline in TM cellularity and a reducing trend in the TMSC content, though this reduction was non-significant in glaucomatous donor eyes. Further studies are essential to elucidate the role of TMSCs in the pathogenesis of primary open angle glaucoma.


2021 ◽  
pp. 108711
Author(s):  
Teruhiko Hamanaka ◽  
Tetsuro Sakurai ◽  
Nobuo Fuse ◽  
Nobuo Ishida ◽  
Toshio Kumasaka ◽  
...  

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Samuel Röhl ◽  
Linnea Eriksson ◽  
Robert Saxelin ◽  
Mariette Lengquist ◽  
Kenneth Caidahl ◽  
...  

Objective: Ultrasound BioMicroscopy (UBM), or high-frequency ultrasound, is a novel technique used for assessment of anatomy and physiology small research animals. In this study, we evaluate the UBM assessment of the re-endothelialization process following denudation of the carotid artery in rats. Methods: Ultrasound BioMicroscopy data from three different experiments were analyzed. A total of 66 rats of three different strains (Sprague-Dawley, Wistar and Goto-Kakizaki) were included in this study. All animals were subjected to common carotid artery balloon injury and examined with UBM 2 and 4 weeks after injury. Re-endothelialization in UBM was measured as the length from the carotid bifurcation to the distal edge of the intimal hyperplasia. En face staining with Evans-blue dye was performed upon euthanization at 4 weeks after injury followed by tissue harvest for morphological and immunohistochemical evaluation. Results: A significant correlation (Spearman r=0.63,p<0.0001) and an agreement according to Bland-Altman test was identified when comparing all measurements of re-endothelialization in high frequency ultrasound and en face staining. Analysis by animal strain revealed a similar pattern and a significant growth in re-endothelialization length measured in UBM from 2 to 4 weeks could be identified. Immunohistochemical staining for von Willebrand factor confirmed the presence of endothelium in the areas detected as re-endothelialized by the ultrasound assessment. Conclusion: Ultrasound BioMicroscopy can be used for longitudinal in vivo assessment of the re-endothelialization following arterial injury in rats.


2020 ◽  
Vol 9 (10) ◽  
pp. 3172 ◽  
Author(s):  
Stefania Vernazza ◽  
Sara Tirendi ◽  
Anna Maria Bassi ◽  
Carlo Enrico Traverso ◽  
Sergio Claudio Saccà

Primary open-angle glaucoma (POAG) is the second leading cause of irreversible blindness worldwide. Increasing evidence suggests oxidative damage and immune response defects are key factors contributing to glaucoma onset. Indeed, both the failure of the trabecular meshwork tissue in the conventional outflow pathway and the neuroinflammation process, which drives the neurodegeneration, seem to be linked to the age-related over-production of free radicals (i.e., mitochondrial dysfunction) and to oxidative stress-linked immunostimulatory signaling. Several previous studies have described a wide range of oxidative stress-related makers which are found in glaucomatous patients, including low levels of antioxidant defences, dysfunction/activation of glial cells, the activation of the NF-κB pathway and the up-regulation of pro-inflammatory cytokines, and so on. However, the intraocular pressure is still currently the only risk factor modifiable by medication or glaucoma surgery. This present review aims to summarize the multiple cellular processes, which promote different risk factors in glaucoma including aging, oxidative stress, trabecular meshwork defects, glial activation response, neurodegenerative insults, and the altered regulation of immune response.


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