December 2002
Volume 43, Issue 13
ARVO Annual Meeting Abstract  |   December 2002
3D Actin Structure in Normal and Glaucomatous Outflow Pathway
Author Affiliations & Notes
  • C Ethier
    Mechanical Engineering & Ophthalmology
    University of Toronto Toronto ON Canada
  • A Read
    Mechanical Engineering
    University of Toronto Toronto ON Canada
  • D Chan
    Mechanical Engineering
    University of Toronto Toronto ON Canada
  • Footnotes
    Commercial Relationships   C. Ethier, None; A. Read, None; D. Chan, None. Grant Identification: CIHR MA-10051
Investigative Ophthalmology & Visual Science December 2002, Vol.43, 1019. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      C Ethier, A Read, D Chan; 3D Actin Structure in Normal and Glaucomatous Outflow Pathway . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1019.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Abstract: : Purpose: Actin structure in cultured trabecular meshwork cells differs between normal and glaucomatous cell lines. Here we describe F-actin architecture in whole tissue, specifically cells of the lining endothelium of Schlemm's canal and juxtacanalicular tissue, in normal and age-matched glaucomatous human eyes. Methods: Enucleated fresh eyes were microdissected to expose the inner and outer walls of Schlemm's canal. Outflow pathway tissues were triply labelled with rhodamine-conjugated phalloidin, Sytox, and polyclonal anti-laminin IgG (secondary antibody: Cy5 conjugated anti-IgG), for visualization of F-actin, nuclei, and basal lamina. Confocal laser microscopy was used to optically section the outer and inner walls of Schlemm's canal, and the JCT. Results: Inner wall cells in normal eyes showed a very prominent peripheral F-actin band midway between the apex and base of the cell, with a few fine actin filaments penetrating into the cell's interior (Figure, showing labelled F-actin and nuclei).  

Moving basally, the F-actin distribution became more random, resulting in a basal cortical network in inner wall cells. JCT cells showed an apparently isotropic, random F-actin network. Outer wall cells showed central actin stress fibres and near-complete absence of a peripheral F-actin band. In glaucomatous eyes (n = 2 pairs to date), the F-actin of inner wall cells was more disordered, with few peripheral actin bands and apparently more cell-cell connections by central fibres. However, we rarely saw cross-linked actin networks (CLANs) in normal or glaucomatous eyes. Frank openings were seen in the laminin under the inner wall in all eyes. Conclusion: F-Actin distribution is markedly different between inner and outer wall cells in normal eyes, and is in turn different than the distribution in cultured Schlemm's canal endothelial cells. These differences are likely attributable to mechanical forces. Preliminary data suggests that actin distribution in glaucoma inner wall cells is qualitatively different than that in normal inner wall cells, which may have important implications for the biomechanics of the inner wall of Schlemm's canal.

Keywords: 601 trabecular meshwork • 383 cytoskeleton • 403 extracellular matrix 

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.