Transcaruncular Orbital Decompression for Dysthyroid Optic Neuropathy

PURPOSE: To determine the efficacy of transcaruncular approach orbital apex decompression for treatment of dysthyroid optic neuropathy. METHODS: In this retrospective noncomparative interventional case series, charts for all patients undergoing orbital decompression surgery for dysthyroid optic neuropathy performed by one author between October 1999 and September 2001 were included in the study. Primary outcome measures included visual acuity, static perimetry, pupillary testing, and color plate testing before and after surgery. Records were also reviewed for changes in extraocular motility and proptosis after surgery and for surgical complications. RESULTS: Sixteen consecutive patients (6 unilateral, 10 bilateral, for a total of 26 cases) underwent orbital apex decompression for dysthyroid optic neuropathy through a transcaruncular approach. In each orbit, the optic neuropathy was refractory to oral corticosteroid therapy. Preoperative visual acuity remained stable or improved in each case. Preoperative Humphrey visual field testing revealed an average mean deviation of -10.3 +/- 6.5 (range, +0.76 to -25.45). Average postoperative mean deviation was -2.79 +/- 2.4 (range, +0.94 to -9.82). Before surgery, 7 of 23 eyes (30%) had full color plates. After surgery, 22 of 23 eyes (96%) had full color plates. Follow-up ranged from 2 to 26 months (mean, 10 months). New-onset diplopia developed in 2 of 10 (20%) patients without preexisting diplopia. CONCLUSIONS: Transcaruncular approach orbital apex decompression effectively treats dysthyroid optic neuropathy.