Characterization of a retinal degeneration mouse model by SD-OCT.

<p>SD-OCT images of control mice retina (A) and <i>rho−/−</i> mice retina (B) from post-natal day 21 (P21) to 180 (P180). Magnification (X2.4) of P21 and P180 control mice outer retina (C) and <i>rho−/−</i> mice (D). (E) Measures of INL thickness obtained from SD-OCT data in control and <i>rho−/−</i> mice (P21: <i>p</i> = 0.0123; P180: <i>p</i> = 0.7125). (F) Measures of ONL thickness obtained from SD-OCT data in control and <i>rho−/−</i> mice (P21 and P180: <i>p</i><0.0001). (G) Measures of ONL thickness obtained from morphometric measurements on cryostat sections in control and <i>rho</i>−/− mice (P15 and P180: p = 0.0022). Statistical significance of the difference between groups was analyzed at the initial time-point (P15 or P21) and the latest time-point (P180) studied by Student's <i>T</i>-test for E and F (n = 23 per group) and by Mann Whitney test for G (n = 6 per group). IPL: inner plexiform layer, INL: inner nuclear layer, ONL: outer nuclear layer, OLM: outer limiting membrane, RPE: retinal pigmented epithelium. SD: Standard Deviation. Scale bars: 50 µm.</p

SD-OCT imaging in other pathological models: rd8 mutation and light-challenge.

<p>(A) Typical ocular lesions of <i>rd8</i> mutation in <i>crb1</i> gene (C57BL/6NRj mice in which presence of the <i>rd8</i> mutation was confirmed by genotyping). (B–C) SD-OCT follow-up of the outer retina during a light-challenge in C57BL/6JRj mice. Control unexposed three month-old mouse has a normal appearance with 4 bands of different reflectance corresponding to the PR segments (B). Mice were then exposed to light during 4 days as described in the “methods” section and the retina was imaged by SD-OCT at day 3 (D3), 7, 14 and 21 after starting the illumination (C). The light-challenge leads to a temporary abolition of the distinction between the two bands forming the outer segment, with a peak at D7 (right panels: enlargement of the area enclosed by a white box on the left view). INL: Inner Nuclear Layer, ONL: Outer Nuclear Layer, IS: Inner Segments, OS: Outer Segments. Scale bars: 50 µm.</p

Retinal layer thickness measures in C57BL/6JRj wild-type mice by SD-OCT and histology.

<p>Retinal thickness in nasal and temporal sides in SD-OCT image (A) and in corresponding histological section (B). (C) Measures of retinal layers thickness by SD-OCT and histology in C57BL/6JRj mice, n = 11, Mann Whitney test. (D) Retinal thickness evaluated by SD-OCT and histology in C57BL/6JRj mice. Each pair of point represents the whole retina thickness of the same eye measured with SD-OCT (blue dots) and histology (orange dots). IPL: inner plexiform layer, INL: inner nuclear layer, OPL: outer plexiform layer, ONL: outer nuclear layer, OLM: outer limiting membrane, RPE: retinal pigmented epithelium. SD: Standard Deviation. Scale bars: 50 µm.</p

Quantification of laser-induced choroidal neovascularization (CNV) in C57BL6/JRj.

<p>(A) Laser-induced CNV (Yag 532 Eyelite parameters: 100 µm, 50 ms, 400 mW) was visualized immediately after laser impact using SD-OCT imaging as described in the “materials and methods” section. Based on this image, a CNV volume is extrapolated using the following formula (4/3π*a*b²)/2, in which <i>a</i> is the polar radius and corresponds to the measure along the vertical axis and <i>b</i> is the equator radius and corresponds to the horizontal axis. (B) Linear regression showing that data obtained from extrapolation or Imaris 3D reconstruction (described step by step hereafter) are statistically equivalent (r² = 0,94, n = 8). (C) Imaris software allows a 3D rendering of SD-OCT imaging. Data shown here arise from the same SD-OCT sequence than shown in panel A. (D) The neovascularization volume, just above the RPE cell layer, was delimitating manually (representative white dotted line in one slice) in about 20 slices (over 100) along z-axis to create a 3D mask. Based on this manual delimitation the Imaris software computed a 3D mask shown in yellow (E). The final visualization, that allowed CNV volume quantification, was obtained after automated mask thresholding (F). OPL: Outer Plexiform Layer, RPE: Retinal Pigmented Epithelium, CHO: Choroid. Scale bar: 50 µm.</p