rss
Br J Ophthalmol doi:10.1136/bjo.2008.150482

Longitudinal profile of retinal ganglion cell damage assessed with blue-light confocal scanning laser ophthalmoscopy after ischemic reperfusion injury

  1. Christopher Kai-shun Leung (tlims00{at}hotmail.com),
  2. James D Lindsey,
  3. Lijia Chen,
  4. Quan Liu,
  5. Robert N Weinreb (weinreb{at}eyecenter.ucsd.edu)
  1. The Chinese University of Hong Kong, Hong Kong
  2. Hamilton Glaucoma Center, UCSD, United States
  3. The Chinese University of Hong Kong, Hong Kong
  4. Hamilton Glaucoma Center, UCSD, United States
  5. Hamilton Glaucoma Center, UCSD, United States
    • Published Online First 17 February 2009

    Abstract

    Purpose: To longitudinally investigate retinal ganglion cell (RGC) expression of Thy-1, a cell-surface glycoprotein specifically expressed in RGCs, with a blue-light confocal scanning laser ophthalmoscope, following retinal ischemia induced by acute elevation of intraocular pressure.

    Methods: A blue-light confocal scanning laser ophthalmoscope (bCSLO, 460nm excitation and 490nm detection) was used to image Thy1-CFP mice before and weekly for 4 weeks after transiently elevating the intraocular pressure to 115 mmHg for 45 minutes (n=4) or 90 minutes (n=5) to induce ischemic injury. Corresponding retinal areas before and after the IOP elevation, during the period of ischemic reperfusion, were compared and the fluorescent spots (Thy-1 expressing RGCs) were counted. The longitudinal profile of CFP-expressing RGCs was modeled with a linear regression equation. The spatial distribution of RGC damage was analyzed in the superior, nasal, inferior and temporal quadrants of the retina.

    Results: No significant change was found at 4 weeks after 45 minutes of IOP elevation (n=4, p=0.465). The average RGC densities before and 4 weeks after IOP elevation were 1660+/-242cells/mm2 and 1624+/-209cells/mm2, respectively. However, significant loss of CFP-expressing RGCs was detected at 1 week following 90 minutes of IOP elevation (n=5, p<0.001). After this initial RGC loss, no significant change was detected subsequently. The proportion of RGC fluorescence remaining was variable and ranged from 14.5% to 79.5% at 4 weeks after the IOP elevation. The average RGC densities before and 4 weeks after IOP elevation were 1443+/-162cells/mm2 and 680+/-385cells/mm2, respectively. Diffuse loss of fluorescent RGCs were observed in the spatial distribution analysis.

    Conclusions: The longitudinal profile of Thy-1 expressing RGC fluorescence loss after ischemic injury is non-progressive and unrelated to the duration of reperfusion.

    Register for free content

    The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

    Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.