Figure 4. Light microscopic changes in rd12 retinas at various ages

Retinas appeared normal at 6 weeks of age except some occasional outer segments (OS) voids (A). The thickness of the OS and outer nuclear layer (ONL) remained nearly normal at 3 months although OS were more disorganized and exhibited more voids (B). By 7 months, only 6 to 7 rows of ONL nuclei remained (C). By 27 months, most of the OS disappeared or were greatly shortened and only 3-4 layers of ONL nuclei remained (D). The scale bar represents 20 μm.