Optic neuritis

Case history #1

A 30-year-old woman presents to the emergency department complaining of decreased vision in her right eye. The decreased vision started suddenly with blurred vision ('seeing as if through fog') and deteriorated over 2 days to the point that she was unable to see at all. She describes retro-ocular pain and pain with any movements of her right eye. On examination there is a right relative afferent pupillary defect, while the right optic disc appears normal. Her visual acuity is 20/200 as recorded on the Snellen chart in her right eye, with a large central visual field defect, and 20/20 in her left eye. She reports no prior history of ophthalmological or neurological problems. The remainder of the ophthalmological and neurological examination is normal.

Case history #2

A 47-year-old woman with a neurological history of transverse myelitis 1 year ago and with residual spastic paraparesis presents with a 1-week history of acute loss of vision in both eyes. The decrease in vision started suddenly with blurred vision, and it has deteriorated over 2 days such that she is virtually unable to see at all with the right eye and barely able to distinguish faces with the left eye. There is an associated retro-ocular pain in both eyes and with eye movements. On examination there is a right relative afferent pupillary defect, and both optic discs appear slightly oedematous. Her visual acuity is hand movements in the right eye and 20/200 in her left eye, with large bilateral central scotomata. The remainder of the ophthalmological examination is normal. Neurological examination reveals bilateral leg weakness and sensory loss with strength 3/5 in both legs on the MRC scale and a spastic ataxic gait.

Other presentations

Atypical presentations can include bilateral presentation or more protracted time to peak of visual acuity loss (e.g., over 3 weeks or more).

A highly specific feature of inflammatory optic neuropathies (optic neuritis) is the presence of pain in the eye or retro-ocular pain, and pain with eye movements. Milder forms may present only with some discomfort in the eye or with eye movements without visual acuity decrease, or mild colour de-saturation (de-saturation is the degree to which a colour is mixed with white).