Ophthalmology update for primary practitioners. Part I. Update on optic neuritis.

Optic neuritis is a common cause of acute visual loss. It is typified by sudden onset of visual impairment and pain with eye movements, followed by spontaneous recovery of vision over several months. Pathologically, optic neuritis is an acute demyelinating event affecting the optic nerve. Objective physical findings are typically few, including an afferent pupillary defect or Marcus-Gunn pupil, whereas subjective psychophysical findings abound (ie, diminished central visual acuity, color vision, decreased contrast sensitivity, and visual field abnormalities). These characteristics have made the diagnosis of optic neuritis based solely on clinical grounds disquieting to practitioner and patient alike. In addition, the fact that optic neuritis is often associated with multiple sclerosis as the first clinical manifestation of disease gives further reason for both patient and physician anxiety. The serious nature of visual loss and the consequences of making the diagnosis of optic neuritis has given rise to extensive testing and expensive treatments. This review is intended to explore our current state of knowledge with regard to (1) clinical presentation, (2) ancillary testing, (3) therapeutic intervention, and (4) associated disease, specifically the risk for multiple sclerosis in the patient who presents with an acute optic neuritis. Finally, a suggestion guide for informing the patient and addressing his or her concerns will be presented.