In their British Ophthalmic Surveillance Unit (BOSU) study on dysthyroid optic neuropathy (DON), Wong and colleagues  report an annual incidence of 0.75 per million per annum, i.e. around 50 patients per year in the UK, which fits with previously published data . Surprisingly however, almost half of their patients who were followed up for 9 months went on to have orbital decompression surgery (47%), despite initial medical therapy—and with a mean delay of only 2.5 months post presentation .
We should like to contrast this need for swift surgical intervention with evidence from our centre where we have for long used an alternative, ciclosporin-based medical regimen, unlike the BOSU study which reported predominantly i.v. methylprednisolone followed by oral steroid and occasional addition of radiotherapy (two patients), rituximab (1) or azathioprine (1). We retrospectively reviewed electronic case records spanning 23 years from our unit and identified 522 patients with thyroid eye disease (TED), of which 145 were considered sight-threatening as defined by EUGOGO , and 75 had DON. During the 12-month period of the BOSU study we saw one patient with DON at presentation. All 75 DON patients were followed up for between 2 and 10 years and had been treated with the Cambridge regimen: three pulses of i.v. methylprednisolone 10 mg/kg at 48-hour intervals, followed by low dose tapering oral prednisolone, starting at 30 mg, then 25, 20, 17.5, 15 mg (3 weeks at each dose) then subsequent reduction by 1 mg per month, and ciclosporin A (Neoral) starting at 2 mg/kg twice daily. As part of the regimen we aim for a ciclosporin trough level of 150–200 micrograms/L during the first six months, then 100 to 150 mcg/L for the second six months and 50–100 mcg/L thereafter. Ciclosporin is then gradually withdrawn over six months after prednisolone the has been stopped.
Seventy of the 75 DON patients (93%) recovered their premorbid visual acuities and 69 of 75 patients (92%) recovered premorbid visual fields. Interestingly, only five patients required surgical decompression of their orbits following our medical regime, with all five having presented with complicated or delayed presentations.
These data point to a potential role for ciclosporin in helping to reduce the need for orbital decompression surgery in DON. Previously, we have shown that ciclosporin therapy rapidly reduces the circulating anti-TSH receptor antibody, further evidence of its utility for TED . Orbital wall decompression is associated with significant risks: the BOSU study reports one patient who developed perception of light vision following surgery and another developed intractable diplopia.
Wong Y, Dickinson J, Perros P, Dayan C, Veeramani P, Morris D, et al. A British Ophthalmological Surveillance Unit (BOSU) study into dysthyroid optic neuropathy in the United Kingdom. Eye. 2018;32:1555–62.
Perros P, Hegedius L, Bartalena L, Marocci C, Kahaly GJ, Baldeschi L, et al. Graves’ Orbitopathy as a rare disease in Europe: a European Group on Graves’ Orbitopathy (EUGOGO) position statement. Orphanet J Rare Dis. 2017;12:72.
Bartalena L, Baldeschi L, Dickinson A, Eckstein A, Kendall-Taylor P, Marcocci C, et al. European Group on Graves’ Orbitopathy (EUGOGO). Consensus statement of the European Group on Graves’ orbitopathy (EUGOGO) on management of GO. Eur J Endocrinol. 2008;158:273–85.
Roos JCP, Paulpandian V, Murthy R. Serial TSH-receptor antibody levels to guide the management of thyroid eye disease: the impact of smoking, immunosuppression, radio-iodine, and thyroidectomy.Eye (Lond). 2018 Nov 6. doi: 10.1038/s41433-018-0242-9. [Epub ahead of print]
The authors would like to acknowledge helpful discussions with Drs. Nima Ghadiri and Paul Meyer.
Conflict of interest
The authors declare that they have no conflict of interest.
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Roos, J.C.P., Murthy, R. Comment on: A British Ophthalmic Surveillance Unit (BOSU) study into dysthyroid optic neuropathy in the United Kingdom. Eye 33, 327–342 (2019). https://doi.org/10.1038/s41433-018-0303-0