Endocrine Abstracts

A 61-year-old ex-smoker with a background of chronic obstructive pulmonary disease, bilateral cataracts and advanced retinitis pigmentosa presented in April 2014 with a 5 months history of feeling generally unwell and weight loss. He was found thyrotoxic with TSH suppressed to less than 0.01 mU/l, free T₄ of 38 pmol/l and free T₃ of 26 pmol/l. On examination there was tunnel vision bilaterally and diplopia in all directions with no evidence of thyroid eye disease. He was initiated on carbimazole 20 mg once a day. The impression was of thyrotoxicosis and a strongly positive thyroid receptor antibody confirmed Graves’ disease. He responded well to the treatment and gained weight. His thyroid function continued to improve and the dose of carbimazole has been gradually reduced.

In September he developed a foreign body sensation particularly in the left eye and pain on eye movement. There was conjunctival injection and periorbital oedema, mild proptosis, bilateral chemosis, lid oedema and erythema. He was prescribed topical lubricants and referred to ophthalmology who diagnosed moderate orbitopathy. Given difficulties in fully assessing his vision owing to his retinitis pigmentosa related optic neuropathy he underwent a MRI scan of his orbits which confirmed thyroid ophthalmopathy with active inflammation of the extraocular muscles and bilateral straightening of the optic nerves, suggestive of nerve stretching. In March 2015 he developed a significant flare up of his thyroid eye disease and was offered an intravenous methylprednisolone (six doses administered weekly). He did not respond well to this and subsequently was considered for orbital radiotherapy. He received a course of low dose radiotherapy – 20 Gy/12F. On follow up there was symptomatic benefit and was able to use less strong prisms. His vision was 6/24 in both eyes. 18 months since initiating carbimazole treatment he was receiving 5 mg daily and it was advised to further reduce it to 5 mg alternate days to prevent relapse of Graves’ disease. Once confirmed the thyroid eye disease was inactive his carbimazole was stopped and he was discharged from the endocrinology clinic. In summary, we presented a difficult to manage case of thyroid eye disease complicated by concurrent illness requiring multidisciplinary approach to ensure patient’s best outcome.