Figure 5.

Retinal morphology of wt (a–f) and R91W;Nrl^−/− (g–m) mice at indicated time points after blue light exposure. Boxed images (e, f, k–m) are high-magnification images of retinas at the +3d time point. All photoreceptors within the hotspot were pyknotic (black arrows) in wt mice at 24 h (b). ONL thinning, subretinal accumulation of large cells, presumably microglia/macrophages (white arrows), disruption and vesiculation of the RPE was detected 3 days after the insult (c, e, f). No photoreceptors remained in the hotspot region of wt at 10 days after exposure (d). In R91W;Nrl^−/− mice pyknotic nuclei were detected in the ONL but also in the INL at 24 h after BLD (h). Three days following light damage (i, k–m) blood cells (white arrowheads) appeared in the OPL, ONL and in the subretinal space (i, k). Cystoid spaces (*) emerged throughout the outer retina (i, k, l) including the INL (m). The RPE occasionally thickened (i, k) and macrophage/microglia (white arrows) cells were detected in the subretinal space (l). Ten days after BLD, only a reduced number of nuclei in the ONL revealed the position of the hotspot. All other signs of blue light-induced damage have been resolved (j). Black arrows: pyknotic nuclei. White arrows: macrophage/microglia. Arrowheads: blood cells. *: cystoid spaces. OS: outer segments, IS: inner segments, other abbreviations as in Figures 1 and 3. Scale bars are as indicated for boxed and unboxed images. N=3 per time point and strain