13th February 2025

A 50-year-old Caucasian female presents with acutely red eyes and diplopia over a period of 4 weeks.

A 50-year-old Caucasian female presents with acutely red eyes and diplopia over a period of 4 weeks. Past medical history includes rheumatoid arthritis, although she says this is well controlled.

Examination reveals significant bilateral proptosis with mild restriction of elevation and depression. Her pupils are normal and the rest of her cranial nerves are intact.

Her most recent thyroid function tests show:

TSH: 0.2 mU/L (0.4 – 4mU/L)

Serum free T4: 30 pmol/L (10.0-22.0)

Which of the following would support the likely diagnosis?

Select the SINGLE most appropriate option from the list below. Select ONE option only.