A 47-year-old woman presented with a two-week history of a sore throat and a “dirty” sensation in her left eye, followed by a week of reduced vision in the same eye and pain on eye movement. Her visual acuity was 6/6 on the right and 6/60 on the left, with a marked afferent pupillary defect and a slightly larger left pupil. There was reduced colour vision in the left eye and she had a pale left optic disc. She had a past history of spontaneous abortion aged 24, but subsequently had three children. She had also experienced recurrent joint pains when she was aged 38, and had been diagnosed with bronchiectasis at the age of 42 and Sjögren’s syndrome one year later. Her sister had ankylosing spondylitis, her brother Buerger’s disease and her grandmother had had rheumatoid arthritis.

COMMENT

The initial presentation was with a left inflammatory optic neuropathy (or optic neuritis) for which there is a wide differential diagnosis:

• demyelinating (multiple sclerosis, acute demyelinating encephalomyelitis (ADEM))

• autoimmune (systemic lupus erythematosus (SLE), Behçet’s disease, autoimmune optic neuritis)

• granulomatous (sarcoidosis, tuberculosis)

• neoplastic (meningioma, pituitary tumour or metastasis)

• infectious (bartonella, borrelia, syphilis)

• post-infectious

• post-vaccination

• and even vitamin B12 deficiency or dysthyroid eye disease.1

Because optic neuritis is a common presenting feature of multiple sclerosis and because this patient came from an area of high prevalence, this would seem on the surface to be the most likely.2 However, her history of spontaneous abortion, undiagnosed recurrent arthralgias, recent diagnosis of Sjögren’s syndrome and family history points towards an underlying autoimmune tendency or connective tissue disorder.

This was later supported by the following investigation results: white blood cell count 3.3×109/l (neutrophils 2.1×109 …