Longitudinal in vivo imaging of retinal ganglion cells and retinal thickness changes following optic nerve injury in mice

• Published in: PloS one 2012-06, Vol.7 (6), p.e40352-e40352
• Main Authors: Chauhan, Balwantray C, Stevens, Kelly T, Levesque, Julie M, Nuschke, Andrea C, Sharpe, Glen P, O'Leary, Neil, Archibald, Michele L, Wang, Xu
• Format: Article
• Language: English
• Subjects: Animal models; Animals; Apoptosis; Biology; Biophysics; Cell density; Cell Survival; Change detection; Density; Eye; Eye diseases; Eye injuries; Financial planners; Fluorescence; Ganglion cysts; Genetic engineering; Glaucoma; Green Fluorescent Proteins - metabolism; Hypertension; Imaging; Laboratory animals; Lasers; Medical imaging; Medicine; Mice; Neuropathy; Neurosciences; Ophthalmoscopy - methods; Optic nerve; Optic Nerve Injuries - pathology; Optic neuropathy; Optical Coherence Tomography; Optics; Physiology; Promoter Regions, Genetic - genetics; Raster; Raster scanning; Respiration; Retina; Retinal ganglion cells; Retinal Ganglion Cells - pathology; Studies; Thy-1 Antigens - genetics; Tomography, Optical Coherence - methods; Transgenic mice
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0040352

Retinal ganglion cells (RGCs) die in sight-threatening eye diseases. Imaging RGCs in humans is not currently possible and proof of principle in experimental models is fundamental for future development. Our objective was to quantify RGC density and retinal thickness following optic nerve transection in transgenic mice expressing cyan fluorescent protein (CFP) under control of the Thy1 promoter, expressed by RGCs and other neurons. A modified confocal scanning laser ophthalmoscopy (CSLO)/spectral-domain optical coherence tomography (SD-OCT) camera was used to image and quantify CFP+ cells in mice from the B6.Cg-Tg(Thy1-CFP)23Jrs/J line. SD-OCT circle (1 B-scan), raster (37 B-scans) and radial (24 B-scans) scans of the retina were also obtained. CSLO was performed at baseline (n = 11) and 3 (n = 11), 5 (n = 4), 7 (n = 10), 10 (n = 6), 14 (n = 7) and 21 (n = 5) days post-transection, while SD-OCT was performed at baseline and 7, 14 and 35 days (n = 9) post-transection. Longitudinal change in CFP+ cell density and retinal thickness were computed. Compared to baseline, the mean (SD) percentage CFP+ cells remaining at 3, 5, 7, 10, 14 and 21 days post-transection was 86 (9)%, 63 (11)%, 45 (11)%, 31 (9)%, 20 (9)% and 8 (4)%, respectively. Compared to baseline, the mean (SD) retinal thickness at 7 days post-transection was 97 (3)%, 98 (2)% and 97 (4)% for the circle, raster and radial scans, respectively. The corresponding figures at 14 and 35 days post-transection were 96 (3)%, 97 (2)% and 95 (3)%; and 93 (3)%, 94 (3)% and 92 (3)%. Longitudinal imaging showed an exponential decline in CFP+ cell density and a small (≤8%) reduction in SD-OCT measured retinal thickness post-transection. SD-OCT is a promising tool for detecting structural changes in experimental optic neuropathy. These results represent an important step towards translation for clinical use.