scholarly journals Anatomic Changes in Schlemm's Canal and Collector Channels in Normal and Primary Open-Angle Glaucoma Eyes Using Low and High Perfusion Pressures

2014 ◽  
Vol 55 (9) ◽  
pp. 5834 ◽  
Author(s):  
Cheryl R. Hann ◽  
Andrew J. Vercnocke ◽  
Michael D. Bentley ◽  
Steven M. Jorgensen ◽  
Michael P. Fautsch
Keyword(s):  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
Open Angle ◽  
Schlemm’S Canal ◽  
Schlemm's Canal

scholarly journals Reduction in trabecular meshwork stem cell content in donor eyes with primary open angle glaucoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yogapriya Sundaresan ◽  
Lakshmi Priya Manivannan ◽  
Shanthi Radhakrishnan ◽  
Krishnadas Subbiah Ramasamy ◽  
Muthukkaruppan Veerappan ◽  
...  
Keyword(s):  
Stem Cell ◽  
Trabecular Meshwork ◽  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
Stem Cell Marker ◽  
Histopathological Analysis ◽  
Open Angle ◽  
Cell Marker ◽  
Schlemm’S Canal ◽  
Schlemm's Canal

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.

scholarly journals Fundamental Biomaterial Considerations in the Development of a 3D Model Representative of Primary Open Angle Glaucoma

2021 ◽  
Vol 8 (11) ◽  
pp. 147
Author(s):  
Hannah C. Lamont ◽  
Imran Masood ◽  
Liam M. Grover ◽  
Alicia J. El Haj ◽  
Lisa J. Hill
Keyword(s):  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
In Vitro Models ◽  
Open Angle ◽  
Schlemm’S Canal ◽  
Schlemm's Canal ◽  
Future Success ◽  
Central Regions

Glaucoma is a leading cause of irreversible blindness globally, with primary open angle glaucoma (POAG) being the most common subset. Raised intraocular pressure is an important risk factor for POAG and is caused by a reduction in aqueous humour (AqH) outflow due to dysfunctional cellular and matrix dynamics in the eye’s main drainage site, the trabecular meshwork (TM) and Schlemm’s canal (SC). The TM/SC are highly specialised tissues that regulate AqH outflow; however, their exact mechanisms of AqH outflow control are still not fully understood. Emulating physiologically relevant 3D TM/S in vitro models poses challenges to accurately mimic the complex biophysical and biochemical cues that take place in healthy and glaucomatous TM/SC in vivo. With development of such models still in its infancy, there is a clear need for more well-defined approaches that will accurately contrast the two central regions that become dysfunctional in POAG; the juxtacanalicular tissue (JCT) region of the TM and inner wall endothelia of the Schlemm’s canal (eSC). This review will discuss the unique biological and biomechanical characteristics that are thought to influence AqH outflow and POAG progression. Further consideration into fundamental biomaterial attributes for the formation of a biomimetic POAG/AqH outflow model will also be explored for future success in pre-clinical drug discovery and disease translation.

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