June 2017
Volume 58, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2017
Changes in the Radial Peri-papillary Capillaries (RPCs) in human retina during ‘physiological aging’: the forgotten vascular bed in glaucoma pathogenesis
Author Affiliations & Notes
  • Tailoi Chan-Ling
    Department of Anatomy & Histology, University of Sydney, Sydney, New South Wales, Australia
  • Samyoul Ahn
    Department of Anatomy & Histology, University of Sydney, Sydney, New South Wales, Australia
  • Mark Koina
    ACT Pathology, Garran, Australian Capital Territory, Australia
  • Mohammad Nasir Uddin
    Department of Anatomy & Histology, University of Sydney, Sydney, New South Wales, Australia
  • Ted Maddess
    Diagnostics for Eye Diseases Group, Australian National University, Canberra, New South Wales, Australia
  • Samuel Adamson
    Department of Anatomy & Histology, University of Sydney, Sydney, New South Wales, Australia
  • Marconi Barbosa
    Diagnostics for Eye Diseases Group, Australian National University, Canberra, New South Wales, Australia
  • Footnotes
    Commercial Relationships   Tailoi Chan-Ling, None; Samyoul Ahn, None; Mark Koina, None; Mohammad Nasir Uddin, None; Ted Maddess, None; Samuel Adamson, None; Marconi Barbosa, None
  • Footnotes
    Support  This work was supported by the Baxter Charitable Foundation, and the Brian M. Kirby Gift of Sight Initiative
Investigative Ophthalmology & Visual Science June 2017, Vol.58, 3391. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Tailoi Chan-Ling, Samyoul Ahn, Mark Koina, Mohammad Nasir Uddin, Ted Maddess, Samuel Adamson, Marconi Barbosa; Changes in the Radial Peri-papillary Capillaries (RPCs) in human retina during ‘physiological aging’: the forgotten vascular bed in glaucoma pathogenesis. Invest. Ophthalmol. Vis. Sci. 2017;58(8):3391.

      Download citation file:


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

      ×
  • Supplements
Abstract

Purpose : To characterize the structure, distribution, caliber & glial ensheathment of radial peri-papillary capillaries (RPCs) in human retina & their changes during ‘physiological aging’.

Methods : A total of 53 human eyes including 1 young (aged 9) and 52 adults (aged 17-84) were examined. Multiple marker immunohistochemistry was performed with markers CD34, CD39, GFAP, NG2, α-SMA, S-100b, NF, Neu-N and UEA-1 Lectin to examine vascular density, astrocyte & pericyte ensheathement, RPC distribution, vascular branching patterns and CD39 expression levels. RPCs ultrastructure was examined using TEM.

Results : RPCs are located within 6μm of the inner limiting membrane and have unique ultrastructural features including thin basal lamina, sparse astrocyte & pericyte ensheathment, and importantly, luminal diameter of 4-5μm as compared to capillaries in the superficial vascular plexus. The outer limit of RPCs extended significantly further than previously reported by Henkind (1967) & showed a higher anastomosis, suggesting higher perfusion efficiency in healthy young adults. Mapping of the outer limit of the RPCs & quantitative morphological analysis in 48 adult retinas showed that their extent, caliber & vessel density decreased significantly with age. CD39 expression intensity & vascular density were also found to decrease. Importantly, not only did the extent & density of RPCs decrease with age, many RPC segments showed marked decrease in caliber with some segments appearing collapsed, suggestive of a compromised rheology. Vessel caliber showed a decrease from 7-7.5μm in healthy young adults to 6μm in the 8th decade.

Conclusions : The superficial location and thin basal lamina of RPCs make them susceptible to lumen collapse under high intraocular pressure, while their restriction to the nerve fiber layer makes them responsible for the metabolic needs of the ganglion cell axons, making their functional capacity particularly relevant to glaucoma pathogenesis. Further, CD39 plays a major role in ATP-dependent processes as well as preventing thrombotic & inflammatory processes. The significant reduction in CD39 expression will further compromise RPCs function during ‘physiological aging’. These findings are supportive of the utility of quantitative analysis of RPCs as an indicator of glaucoma predisposition, requiring further study in glaucomatous population.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

×
×

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.

×