Transferred NMP leads to structural rescue of the rds+/− phenotype. Light micrographs (top rows) and electron micrographs (bottom rows, n=3–5/group) from the temporal side of rds+/− eyes were examined. After P5 (A) or P22 (B) injection, moderate ultrastructural rescue is detected in the OSs of nanoparticle-injected eyes (arrows) at PI-30; significant ultrastructural improvement in OSs of nanoparticle-injected eyes is apparent by PI-120. OS discs are properly aligned and flattened, and improved OSs do not exhibit the swirl-like structures typical of the rds+/−. IS, inner segment layer; RPE, retinal pigment epithelium. Scale bars = 10 μm.