Hereditary Optic Neuropathies

Abstract Hereditary optic neuropathies are a group of disorders characterized by optic nerve damage in which the underlying cause is heritable. Optic atrophy is a clinical state in which there is pallor of the optic nerve due to loss of ganglion cell axons and supporting microvascular tissue, often associated with decreased vision. Optic neuropathy is a more general term that includes the early phase of the disease when optic atrophy may not yet be present. Clinical severity may vary from lack of symptoms to complete blindness. Hereditary causes of optic neuropathy include primary optic nerve disease; compression by a genetically determined tumor, for example, in neurofibromatosis; or degeneration, as occurs in the later stages of retinitis pigmentosa. Although glaucoma is an optic neuropathy and has features like other hereditary optic neuropathies, it is not discussed in this chapter. Optic atrophy may be an isolated event or may be associated with other neurologic or systemic manifestations. In this chapter we discuss Kjer autosomal dominant optic atrophy and Leber hereditary optic neuropathy (LHON) as well as optic atrophy associated with Wolfram syndrome and some of the neurodegenerative diseases. Mitochondrial dysfunction appears to be a common denominator in many of the hereditary optic neuropathies.