Figure 2
Photoreceptors cell death after a total dose of 2.2 J/cm2. Male Wistar rats aged 7 weeks were exposed to GaN-on-GaN (GoG) LED or conventional white LED (XE) (Xanlite XXX Evolution 5 W) for 9 and 10 h respectively at 1900 lx, receiving the estimated retinal dose of 2.2 J/cm2 (BLH weighted 0.253 J/cm2 for regular LED and to 0.26 J/cm2 for GaN-on-GaN LED). 15 hours after the end of the exposure period the eyes were included in optimal cutting temperature medium (Tissue Tek), cryosectioned and immunostained. NE: Non exposed. (A) 15 hours after the end of the exposure period the eyes were included in optimal cutting temperature medium (Tissue Tek), cryosectioned and stained with the TUNEL assay (TUNEL). Nuclei were stained in blue with DAPI. ONL indicates the outer nuclear layer, INL the Inner nuclear layer and GCL the ganglion cell layer. Scale bar represents 100 µm. Photographs show representative images of the upper retina. (B) Quantification of TUNEL positive cells in exposed retinas from independent experiments. Histograms represent the median with the interquartile range. Significance was evaluated using the Kruskal-Wallis test followed by the Dunn’s multiple comparison post-test. H(3) = 10.83 044. **p ≤ 0.1, n = 4. (C) Quantification of the thickness of photoreceptors nuclei layer in exposed retinas. Histograms represent the median with the interquartile range. Significance was evaluated using the Kruskal-Wallis test followed by the Dunn’s multiple comparison post-test. H(3) = 9.846. **p ≤ 0.05, n = 4.
