Purpose: To investigate the outcomes of orbital decompression surgery for dysthyroid optic neuropathy associated with severe Graves’ ophthalmopathy. 
Design: Ten years (2000-2010) retrospective case series.
Methods: Thirty-eight orbits (with dysthyroid optic neuropathy) of 119 surgical orbital decompressions. Patients with dysthyroid optic neuropathy associated with Graves’ ophthalmopathy, who underwent orbital decompression surgery at Sydney Eye Hospital (Sydney, Australia), were investigated for outcome measures.
Results: Thirty-five orbits were eligible for data analysis. Orbital decompression surgery improved visual acuity in 29 orbits and maintained visual acuity in four orbits. In patients with dysthyroid optic neuropathy, there was a statistically significant mean improvement in visual acuity of 2.8 lines postoperatively (standard deviation = 3.2; 95% confidence interval 3.9 to 1.7, p-value < 0.05). There were no statistically significant differences in
visual acuity amongst different combinations of orbital walls being decompressed, with the majority of orbits had the medial orbital wall decompressed. This may reflect the small number of decompressions performed in each subgroup. Orbital decompression surgery reduced proptosis by a mean of 3.2 mm (standard deviation = 2.9; 95% confidence interval -4.32 to -2.07; p-value < 0.05). Medial and lateral orbital walls decompression resulted in the greatest mean reduction in proptosis. There were no severe visual impairment cases postoperatively (VA worse than 6/60). There were two patients with new onset diplopia postoperatively. There were three orbits with bleeding and one orbit with CSF leakage, all without major sequelae postoperatively.
Conclusion: Regardless of surgical access, orbital decompression surgery is effective and safe in the management of dysthyroid optic neuropathy and in reducing proptosis in patients with Graves’ ophthalmopathy.