Optic atrophy is the loss of some or most of the fibers of the optic nerve http://www.kellogg.umich.edu/patientcare/conditions/optic.atrophy.html. In medicine, "atrophy" usually means "shrunken but capable of regrowth", so some argue that "optic atrophy" as a pathological term is somewhat misleading and use "optic neuropathy" instead. The optic nerve is part of the brain and has no capability for regeneration.