Walsh & Hoyt: Distinguishing an Optic Neuropathy from Retinal Disease

Severe optic neuropathies associated with syndromes and producing profound losses of optic nerve functions may be obvious. However, mild optic neuropathies may only produce subtle impairments of visual function and be difficult to diagnose. When the optic discs appear normal and the visual field defects do not have a classical pattern, distinguishing such a mild optic neuropathy from retinal disease may be difficult. For example, optic neuritis can be an easy diagnosis, but when it produces very mild loss of vision, it may be easily confused with central serous retinopathy. Both occur in young adults and can present as acute, painless, mild monocular visual loss. The relative absence of fundus findings in such patients further challenges the clinician in sorting out the differential diagnosis. However, since optic nerve disease may be the harbinger of intracranial pathology, and both optic nerve and retinal diseases are often amenable to a variety of therapeutic modalities, it is important for the clinician to make the early and accurate distinction between an optic neuropathy and macular or other retinal disease.