Optic nerve degeneration in proptosis

Source 3.5 year male Lhasa Apso, OD
Fixative formalin
Stain Luxol fast blue
Notes Luxol fast blue stains myelin sheaths; notice that there are essentially no nerve fibers left in this nerve; notice also the somewhat 'spongy' nature of the tissue, due to lipid filled cells (gitter cells, which are phagocytic transformed microglial cells) the result of breakdown of myelin (seen better when the picture is enlarged, often as vacuolated cells with small, eccentric nuclei)
See also normal Luxol fast blue
Illustration Click on image to see larger picture