Walsh & Hoyt: Pathology of Optic Atrophy

The optic nerve axons arise from the ganglion cells located in the retina. Hence damage to such axons may occur at several locations: (a) from disease within the eye that damages the ganglion cells, the retinal nerve fiber layer, or the optic disc; (b) from disease within or surrounding the intraorbital, intracanalicular, or intracranial portions of the optic nerve; (c) from intracranial diseases of the optic chiasm, optic tracts, or lateral geniculate body (LGB); and from diseases of the retrogeniculate pathways that produce transsynaptic (transneuronal) degeneration. Such precesses may be focal, multifocal, or diffuse. They may destroy axons directly or by effects on the blood supply. Focal disruption at any place along an axon causes degeneration of the entire axon and its cell body, the retinal ganglion cell. When large numbers of axons undergo such degeneration, gross shrinkage oratrophy of the optic nerve becomes evident.