Retinal nerve fiber layer measurement by optical coherent tomography in patients with acute optic neuritis

Introduction. The term optic neuritis (ON) define an acute, demyelinating, or idiopathic optic neuropathy. ON can present in isolation or be associated with multiple sclerosis (MS) or occur in the setting of neuromyelitis optica. MS is more common among young and middle aged individuals [1]. The average onset of the disease is at 30 years of age, and it afflicts women more often than men (a ratio of approximately 2:1) [2].The most important factor is probably the loss of signal transmission in some axons due to a conduction block or ganglion cell death [3]. In adults, optic neuritis typically is unilateral, with visual loss evolving over several days, reaching a nadir within 2 weeks, and frequently associated with peri-orbital pain exacerbated by eye movements [4]. In two-thirds of adult patients with optic neuritis, the optic disc appears normal on direct ophthalmoscopy during the acute phase; however, optical coherent tomography (OCT) reveals that many of these affected eyes have subclinical disc oedema [5] (see Fig. 1).