Optic neuropathy refers to disease or damage to the optic nerve, typically characterized by decreased visual acuity, decreased color vision, visual field defect, relative afferent pupillary defect, optic disc edema, and/or optic disc atrophy. Possible etiologies include hereditary, inflammatory, infiltrative, ischemic, demyelinating (optic neuritis), toxic, and compressive optic neuropathies. This chapter discusses the clinical pathway for evaluating and diagnosing optic neuropathy, reviewing the literature in detail.
The diagnosis of an optic neuropathy is usually made on clinical grounds alone. Several excellent references discuss in detail the anatomy of the optic nerve as well as examination techniques.1,2,3 The clinical features of optic neuropathies include decreased visual acuity, decreased color vision, visual field defect, relative afferent pupillary defect (RAPD), optic disc edema, and/or optic disc atrophy. Other more complex (and time-consuming) testing for optic neuropathy, such as visual evoked potentials (VEPs), flicker fusion, formal color vision testing, and contrast sensitivity, can be performed but in general are not required to establish the clinical diagnosis of optic neuropathy and are not discussed here.