Cargando…
Ultrastructural variability of the juxtacanalicular tissue along the inner wall of Schlemm’s canal
PURPOSE: Increased resistance of aqueous humor drainage from the eye through Schlemm’s canal (SC) is the basis for elevated intraocular pressure in glaucoma. Experimental evidence suggests that the bulk of outflow resistance lies in the vicinity of the inner wall endothelial lining of SC and the adj...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Molecular Vision
2019
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776461/ https://www.ncbi.nlm.nih.gov/pubmed/31588175 |
_version_ | 1783456430247903232 |
---|---|
author | Koudouna, Elena Young, Robert D. Overby, Darryl R. Ueno, Morio Kinoshita, Shigeru Knupp, Carlo Quantock, Andrew J. |
author_facet | Koudouna, Elena Young, Robert D. Overby, Darryl R. Ueno, Morio Kinoshita, Shigeru Knupp, Carlo Quantock, Andrew J. |
author_sort | Koudouna, Elena |
collection | PubMed |
description | PURPOSE: Increased resistance of aqueous humor drainage from the eye through Schlemm’s canal (SC) is the basis for elevated intraocular pressure in glaucoma. Experimental evidence suggests that the bulk of outflow resistance lies in the vicinity of the inner wall endothelial lining of SC and the adjacent juxtacanalicular tissue (JCT). However, there is little understanding of how this resistance is generated, and a detailed understanding of the structure-function relationship of the outflow pathway has not been established yet. In the present study, regional variations in the ultrastructure of the JCT and the inner wall of SC were investigated in three dimensions. METHODS: With the use of serial block face scanning electron microscopy (SBF-SEM), the volume occupied by the electron lucent spaces of the JCT compared to that occupied by the cellular and extracellular matrix was investigated and quantified. The distribution of giant vacuoles (GVs) and pores in the inner wall endothelium of SC was further examined. RESULTS: With increasing distance from the inner wall of SC, the volume of the electron lucent spaces increased above 30%. In contrast, the volume of these spaces in immediate contact with the inner wall endothelium was minimal (<10%). Circumferential variability in the type and distribution of GVs was observed, and the percentage of GVs with pores varied between 3% and 27%. CONCLUSIONS: These studies provide a detailed quantitative analysis of the ultrastructure of JCT and the distribution of GVs along the circumference of SC in three dimensions, supporting the non-uniform or segmental aqueous outflow. |
format | Online Article Text |
id | pubmed-6776461 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Molecular Vision |
record_format | MEDLINE/PubMed |
spelling | pubmed-67764612019-10-04 Ultrastructural variability of the juxtacanalicular tissue along the inner wall of Schlemm’s canal Koudouna, Elena Young, Robert D. Overby, Darryl R. Ueno, Morio Kinoshita, Shigeru Knupp, Carlo Quantock, Andrew J. Mol Vis Research Article PURPOSE: Increased resistance of aqueous humor drainage from the eye through Schlemm’s canal (SC) is the basis for elevated intraocular pressure in glaucoma. Experimental evidence suggests that the bulk of outflow resistance lies in the vicinity of the inner wall endothelial lining of SC and the adjacent juxtacanalicular tissue (JCT). However, there is little understanding of how this resistance is generated, and a detailed understanding of the structure-function relationship of the outflow pathway has not been established yet. In the present study, regional variations in the ultrastructure of the JCT and the inner wall of SC were investigated in three dimensions. METHODS: With the use of serial block face scanning electron microscopy (SBF-SEM), the volume occupied by the electron lucent spaces of the JCT compared to that occupied by the cellular and extracellular matrix was investigated and quantified. The distribution of giant vacuoles (GVs) and pores in the inner wall endothelium of SC was further examined. RESULTS: With increasing distance from the inner wall of SC, the volume of the electron lucent spaces increased above 30%. In contrast, the volume of these spaces in immediate contact with the inner wall endothelium was minimal (<10%). Circumferential variability in the type and distribution of GVs was observed, and the percentage of GVs with pores varied between 3% and 27%. CONCLUSIONS: These studies provide a detailed quantitative analysis of the ultrastructure of JCT and the distribution of GVs along the circumference of SC in three dimensions, supporting the non-uniform or segmental aqueous outflow. Molecular Vision 2019-09-21 /pmc/articles/PMC6776461/ /pubmed/31588175 Text en Copyright © 2019 Molecular Vision. http://creativecommons.org/licenses/by-nc-nd/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited, used for non-commercial purposes, and is not altered or transformed. |
spellingShingle | Research Article Koudouna, Elena Young, Robert D. Overby, Darryl R. Ueno, Morio Kinoshita, Shigeru Knupp, Carlo Quantock, Andrew J. Ultrastructural variability of the juxtacanalicular tissue along the inner wall of Schlemm’s canal |
title | Ultrastructural variability of the juxtacanalicular tissue along the inner wall of Schlemm’s canal |
title_full | Ultrastructural variability of the juxtacanalicular tissue along the inner wall of Schlemm’s canal |
title_fullStr | Ultrastructural variability of the juxtacanalicular tissue along the inner wall of Schlemm’s canal |
title_full_unstemmed | Ultrastructural variability of the juxtacanalicular tissue along the inner wall of Schlemm’s canal |
title_short | Ultrastructural variability of the juxtacanalicular tissue along the inner wall of Schlemm’s canal |
title_sort | ultrastructural variability of the juxtacanalicular tissue along the inner wall of schlemm’s canal |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776461/ https://www.ncbi.nlm.nih.gov/pubmed/31588175 |
work_keys_str_mv | AT koudounaelena ultrastructuralvariabilityofthejuxtacanaliculartissuealongtheinnerwallofschlemmscanal AT youngrobertd ultrastructuralvariabilityofthejuxtacanaliculartissuealongtheinnerwallofschlemmscanal AT overbydarrylr ultrastructuralvariabilityofthejuxtacanaliculartissuealongtheinnerwallofschlemmscanal AT uenomorio ultrastructuralvariabilityofthejuxtacanaliculartissuealongtheinnerwallofschlemmscanal AT kinoshitashigeru ultrastructuralvariabilityofthejuxtacanaliculartissuealongtheinnerwallofschlemmscanal AT knuppcarlo ultrastructuralvariabilityofthejuxtacanaliculartissuealongtheinnerwallofschlemmscanal AT quantockandrewj ultrastructuralvariabilityofthejuxtacanaliculartissuealongtheinnerwallofschlemmscanal |