Late-infantile type galactosialidosis. Histopathology of the retina and optic nerve.

We studied histopathologic findings from the retina and optic nerve of a patient with the late-infantile type of galactosialidosis and related them to clinical features of the condition. Markedly fewer ganglion cells were evident histopathologically using light microscopy. Results of histochemical studies demonstrated abnormal accumulation of lipid and proteinaceous material in the residual swollen ganglion cells. Marked loss of myelinated nerve fibers and thickening of the pial septum were also observed in the optic nerve. Both retinal ganglion cells and amacrine cells had intracytoplasmic inclusion bodies, but none were found in the optic nerve. These findings suggested that optic atrophy was induced by axonal wallerian degeneration secondary to retinal ganglion cell death. Although the fundus showed advanced optic nerve atrophy, a cherry red spot was not evident, possibly because of the marked decrease in ganglion cells in this case.