Retinas and optic nerves show consistent patterns of degeneration. A series of retinas and corresponding optic nerves from 4 different mouse eyes. The retinas were stained for βGEO enzyme activity and the optic nerves were sectioned just posterior to the laminar region and silver-stained. (A, B) A retina with extensive staining has a nerve with normal appearing nerve with well-defined bundles of axons. (C, D) A retina with two wedge-shaped regions of cell loss (asterisks) has a nerve with two similar focal areas of axon loss (asterisks). (E, F) A retina with a large region of cell loss (asterisk) in one half and uniform cell loss in the other has a nerve with a large contiguous region devoid of axons (asterisks), while the remainder of the nerve has a uniform depletion of axons. (G, H) A retina with nearly complete cell loss has a nerve with nearly complete axon loss. Each retina is oriented with the superior region to the top. Each optic nerve is oriented with the dorsal nerve to the top. The central retinal artery (A) and vein (V) are indicated. Bar = 0.45 mm (panels A, C, E, G) and 90 μm (panels B, D, F, H).