Photoreceptor survival in dystrophic RCS/lav rats evaluated by H&E staining.

<p>(A, B) Six retinal areas studied were: peripheral, mid-central and central regions of the (a-d) superior and (e-h) inferior retina respectively. (A) H&E staining at p56 showing the retinal morphology of rats receiving: (a, e) no operation, (b, f) surgical sham operation, (c, g) ECT gel without cells, and (d, h) ECT gel with 2x10⁵ cells for 28 days. The ECT with cells group showed better-aligned and thicker ONL than the other control groups. Preservation of photoreceptors at the periphery was better than that of the central areas in all treatment groups. Straight red line denoted the inner boundary of the ONL, adjacent to the inner nuclear layer (INL). Dashed red line represented the outer boundary of the ONL, adjacent to the RPE. Transiting from the peripheral to central retinal regions, ONL cells became more dispersed and the outer ONL boundary became unclear, especially in the (b, f) sham and (g) ECT without cells groups. Scale bar = 25μm. (C) ONL count was significantly affected by both treatments received (p<0.0005) and retinal location (p<0.0005). Among the treatments received, ONL count in the ECT with cell group was significantly higher than the other treatment groups, namely ECT without cells (p = 0.006), sham (p<0.0005) and non-operated group (p<0.0005). As for the retinal location, ONL count in the peripheral retina was higher than the central retina.