Clinical manifestations and treatment outcome of optic neuropathy in thyroid-related orbitopathy.

BACKGROUND AND OBJECTIVE To investigate the incidence and outcome of optic neuropathy associated with thyroid-related orbitopathy. PATIENTS AND METHODS All patients diagnosed as having optic neuropathy associated with thyroid-related orbitopathy who underwent treatment for optic neuropathy between January 1, 1999, and March 1, 2003, were reviewed. Demographic and clinical data were extracted from the oculoplastic registry (electronic medical record). RESULTS Optic neuropathy occurred in 20 of 595 patients with thyroid-related orbitopathy (3.4%). All patients received systemic steroids, 7 patients received orbital steroid injections, and 2 patients were treated with orbital radiotherapy. Orbital decompression was performed in all 26 orbits. Visual acuity improved from a mean of 20/150 to 20/30 (P < .001). Color vision improved from a mean of 5.2/14 to 11/14 (P = .001). The afferent pupillary defect disappeared shortly after treatment for all but 1 case, and improved in all cases. Exophthalmos decreased from 26.4 +/- 2.5 to 21.5 +/- 2.1 mm (P< .001; 95% confidence interval, 3.8 to 5.7). CONCLUSIONS Optic neuropathy manifests rarely in patients with thyroid-related orbitopathy. Monitoring visual acuity or afferent pupillary response may be a reliable way of assessing and monitoring optic neuropathy. In this study, patients had improved visual acuity and optic nerve function after a combination of medical and surgical treatment.