advertisement
Abstract #22207 Published in IGR 10-4
Longitudinal profile of retinal ganglion cell damage after optic nerve crush with blue-light confocal scanning laser ophthalmoscopy
Leung CK; Lindsey JD; Crowston JG; Lijia C; Chiang S; Weinreb RNInvestigative Ophthalmology and Visual Science 2008; 49: 4898-4902
PURPOSE: To investigate the long-term longitudinal profile of retinal ganglion cell (RGC) damage after optic nerve crush with a new technique for in vivo imaging of RGCs. METHODS: A blue-light confocal scanning laser ophthalmoscope (bCSLO; 460 nm excitation, 490 nm detection) was used to image Thy-1 CFP mice aged 6 to 9 months (n = 5) before optic nerve crush, weekly after crush for 3 weeks, and at weeks 10 and 50 after optic nerve crush. A sham procedure was performed in the contralateral eye, and it was imaged as a control. Corresponding retinal areas before and after optic nerve crush were compared, and the fluorescent spots were counted manually. The longitudinal profile of RGC degeneration was modeled and compared with one-phase and two-phase exponential decay equations. RESULTS: A significant and progressive loss of fluorescent spots was found after optic nerve crush with 18.6% ± 2.3%, 11.3% ± 3.4%, 8.8% ± 5.3%, 4.2% ± 3.1%, and 3.3% ± 2.1% of Thy-1-expressing RGCs remaining at weeks 1, 2, 3, 10, and 50, respectively, after optic nerve crush (P < 0.001; n = 5). There was no change in the fluorescence density in the contralateral control (P = 0.893). Two-phase exponential decay (y = 0.03 + 0.83e(-)(2.78t) + 0.14e(-)(0.30t)) was a better fit than one-phase exponential decay (y = 0.94e(-)(1.93t) + 0.06; P = 0.003) equations, with half-lives of fast phase and slow phase of 1.7 days and 16.3 days, respectively. CONCLUSIONS: The longitudinal profile of RGC degeneration after optic nerve crush is characterized by a two-phase exponential decay model. bCSLO imaging provides an efficient and noninvasive approach to the longitudinal study of progressive RGC damage.
Dr. C.K. Leung, Department of Ophthalmology, Hamilton Glaucoma Center, University of California San Diego, La Jolla, CA 92093-0946, USA
