Clinical Manifestations and Treatment outcome of Optic Neuropathy in Thyroid Related Orbitopathy

Abstract

Abstract: : Purpose: To investigate the incidence and outcome of optic neuropathy (ON) associated with thyroid related orbitopathy (TRO). Methods: Retrospective, noncomparative, interventional case series. All patients who were diagnosed with optic neuropathy associated with TRO and underwent treatment for optic neuropathy at the Jules Stein Eye Institute between 1/1/2000 and 3/1/2003. Results: Optic neuropathy occurred in 20 of 595 TRO patients (3.4%), including 6 patients presenting with sequential involvement of both optic nerves. All patients received systemic steroids, 7 patients received orbital steroid injections, and two cases 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 post treatment (P<0.001). Color vision (Ishiara color plates) improved from a mean of 5.2/14 to 11/14 (P=0.001), and the afferent pupillary defect (APD) disappeared shortly after treatment for all but one case and improved in all cases. Treatment resulted in exophthalmos decreasing from 26.4±2.5mm to 21.5±2.1mm, P<0.001, 95% C.I [3.8:5.7]). The intraocular pressure in primary gaze, upgaze, and the difference between primary and upgaze were reduced after treatment. Conclusions: Optic neuropathy is a rare manifestation in patients with TRO. Monitoring visual acuity or color vision may be a more reliable way of assessing optic neuropathy than assessing relative nerve dysfunction such as APD or red desaturation. In our study patients had improved visual acuity and optic nerve function after a combination of medical and surgical treatment

Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • neuro–ophthalmology: optic nerve • orbit