Emergency Orbital Decompression is not a definitive treatment for Dysthyroid Optic Neuropathy (DON)
Claire Feeney, Farzana Rahman, Ravi Lingam, Vickie Lee, Central Middlesex Hospital, London Northwest Healthcare NHS Trust
Case 1: A 82 year old woman presented with thyrotoxic Gravesí disease January 2015. She was started on carbimazole 20 mg and achieved biochemical control within 2 months of treatment. Several weeks later she started to complain of periorbital swelling and she was referred to the multidisciplinary thyroid eye clinic at Central Middlesex Hospital. On assessment she had bilateral proptosis with severe restriction of upgaze. Clinical activity score was 4/7. Diffusion-weighted Magnetic Resonance Imaging (DWI MRI) showed increased signal and enlargement of the inferior recti muscles bilaterally. She was diagnosed with moderate-severe Gravesí Orbitopathy (GO) and a 12 week course of intravenous methylpredisolone (IVMP) treatment was recommended (total dose 4.5g). However her vision quickly deteriorated due to DON and she was admitted to hospital for pulsed methylpredisolone treatment for sight-threatening GO that failed to control her DON and she underwent successful emergency bilateral optic nerve decompression (endoscopic approach) with immediate improvement. Six months later she complained of persistent blurred vision in the left eye with mild relative afferent pupillary defect (RAPD) and DWI MRI confirmed persistent active GO. She went on to receive orbital radiotherapy to treat residual left DON. By August 2017 MRI DWI and clinical disease appeared quiescent and she was finally discharged.
Case 2: A 54 year old woman had sequential GO inflammation in the left then right orbit. She was first seen in the MDT GO clinic with mild left proptosis. Clinical activity score was 2/7 and there was no motility disturbance. She was initially managed conservatively but three months later left orbital inflammation increased substantially and weekly IVMP treatment was commenced for moderate-severe GO in her left orbit. The patient declined orbital radiotherapy and did not attend follow-up. Ten months later she returned to clinic complaining of right orbital pain and diplopia was treated with further IVMP with a reasonable initial response. However 6 months later her right colour vision deteriorated and a RAPD was noted in clinic with a diagnosis of DON. Initial medical treatment improved vision but later relapsed necessitating an urgent right medial wall orbital decompression. Her right vision initially improved then declined again post operatively. She continued to decline orbital radiotherapy and opted instead to take a prolonged course of oral prednisolone which finally brought the disease into remission several months later.
These 2 cases demonstrate the protean manifestations and persistent nature of GO and the need to continue to be vigilant and actively treat the orbital inflammatory disease with immunosuppression and orbital radiotherapy despite successful orbital decompression for DON.