September 2016
Volume 57, Issue 12
Open Access
ARVO Annual Meeting Abstract  |   September 2016
Investigation of the two types of cellular connections of Schlemm's canal inner wall cells and their role in giant vacuole and pore formation by serial block-face scanning electron microscopy
Author Affiliations & Notes
  • Julia Lai
    Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
    Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, United States
  • Dimitr Getchevski
    Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
  • Athan Zavras
    Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
  • Davy Huang
    Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
  • Syian Srikumar
    Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
  • Haiyan Gong
    Ophthalmology, Boston University School of Medicine, Boston, Massachusetts, United States
    Anatomy and Neurobiology, Boston University School of Medicine, Boston, Massachusetts, United States
  • Footnotes
    Commercial Relationships   Julia Lai, None; Dimitr Getchevski, None; Athan Zavras, None; Davy Huang, None; Syian Srikumar, None; Haiyan Gong, None
  • Footnotes
    Support  NIH EY022634 and The Massachusetts Lions Eye Research Fund
Investigative Ophthalmology & Visual Science September 2016, Vol.57, No Pagination Specified. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Julia Lai, Dimitr Getchevski, Athan Zavras, Davy Huang, Syian Srikumar, Haiyan Gong; Investigation of the two types of cellular connections of Schlemm's canal inner wall cells and their role in giant vacuole and pore formation by serial block-face scanning electron microscopy. Invest. Ophthalmol. Vis. Sci. 201657(12):.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose : Previous studies reported that a reduction in pore density occurs in eyes with primary open angle glaucoma (POAG), indicating that this reduction may contribute to the elevated outflow resistance characteristic of this disease. This study aimed to determine, under flow conditions, whether release of connections between Schlemm’s canal (SC) inner wall (IW) cells and underlying juxtacanalicular connective tissue (JCT) cells plays a role in GV formation; and whether decreased amount of cell margin overlap between adjacent IW cells promotes paracellular pore formation using advanced 3D EM reconstruction.

Methods : Normal human eyes (N=3) were either immersion-fixed (0mmHg) or perfusion-fixed (15mmHg). Frontal and radial sections of SC were processed for serial block-face scanning electron microscopy (SBF-SEM). The IW and JCT cells, GVs, and pores were 3D-reconstructed. Morphometric analyses were performed. In each IW cell, total number of connections with underlying JCT cells was determined. Total cell margin length (ML) and zero-overlap length (ZL) of each IW cell were measured to calculate percent zero-overlap length (PZL=ZL/ML). All data was compared between the eyes fixed at 0 and 15mmHg using Student’s t-test.

Results : Total number of connections between each IW cell with underlying JCT cells significantly decreased in the eye fixed at 15mmHg (33±5, N=4 cells) compared to the eyes fixed at 0mmHg (180±12, N=5 cells, p<0.001). The maximum volume of GVs significantly increased in the eye fixed at 15mmHg (199.05±12.11 µm3) compared to those fixed at 0mmHg (74.12±27.54 µm3, p<0.01). All intracellular pores were found only in the thinnest regions of GV walls. The amount of overlap between adjacent IW cells significantly decreased (0.52±0.19µm vs. 3.71±0.20µm, p<0.0001), and PZL increased 26.68% (p=0.001) in the eye fixed at 15mmHg vs. those fixed at 0mmHg. All paracellular pores were found only in regions where the overlap length was zero µm.

Conclusions : Our innovative use of SBF-SEM permits 3D ultrastructural analyses of the two types of cellular connections between IW/JCT and IW/IW cells. Our data suggests that these two types of connections each play a role in GV and pore formation in normal human eyes under flow conditions. Results of this study provide a baseline for future comparison with POAG eyes.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

×
×

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.

×