Transnasal endoscopic orbital decompression and Graves' ophtalmopathy

To assess the validity and the limits of endoscopic endonasal orbital decompression for Graves' ophtalmopathy resistant to the medical theapy.

Between September 1994 and May 1998, 16 patients with Graves' ophtalmopathy resistant to the medical treatment underwent an orbital decompression transnasally. 27 orbits were decompressed. The surgery was bilateral in 11 patients. In the 5 remaining cases, the surgery was unilateral. It was carried out on the left side in 2 cases and on the right side in 3 cases.

Preoperatively, the average visual acuity was 8/10. Postoperatively, the visual acuity was 9.5/10. The average preoperative exophtalmometry measurement was 25.04 mm and the average postoperative measurement was 21.83 mm. The average retrodisplacement was 3.17 mm (range: 2-8). Preoperatively, 3 patients had mild diplopia whereas 5 others had moderate to severe extraocular muscle dysfunction. Postoperatively, 6 patients had mild diplopia whereas 10 patients required squint surgery for moderate to severe extraocular muscle dysfunction.

Endoscopic orbital decompression improve all the symptoms of Graves' ophtalmopathy but one: the extraocular muscle dysfunction. Its cardinal indication is the treatment of compressive optic neuropathy whereas this surgical approach provides an excellent control of the medial wall of the orbit and the orbital apex. But the average reduction of proptosis of 3.17 mm is not high enough to propose this approach alone for the treatment of disfiguring proptosis. In such cases, a 2 or 3 wall orbital decompression should be performed to get marked cosmetic and functional improvement. In all cases, the patient should be informed about the risk of postoperative diplopia.