Orbital decompression in Graves' orbitopathy: a combined endoscopic and external lateral approach.

Aims: First, to assess the outcomes of endoscopic and external lateral orbital decompression in patients with dysthyroid orbitopathy. Second, to establish a correlation between the percentage of postoperative diplopia and the technique used.

Methods: A retrospective review of 40 patients (73 eyes) who underwent endoscopic medial orbital decompression and external lateral orbital decompression between 1997 and 2003 at the Hôpital Enfant-Jesus in Quebec City. Some of these patients also had an inferior endoscopic decompression. All patients had exophthalmos. The principal indications for surgery were 42 eyes with compressive optic neuropathy, 13 eyes with other ocular disorders, and 18 eyes with exophthalmos only. All patients with neuropathy underwent endoscopic decompression of the optic canal.

Results: All patients had satisfactory improvement of their ocular pathology. Optic neuropathy was completely resolved in 92.85% (39 of 42 eyes). In patients who did not have preoperative diplopia (26), diplopia developed in 70% (14 of 20) of those who underwent medial and inferior decompression compared with 16.6% (1 of 6) of patients who underwent medial decompression only.

Conclusion: Endoscopic medial orbital decompression is very effective in resolving compressive optic neuropathy. Preservation of the orbital floor, when the degree of exophthalmos allows, reduces the incidence of postoperative diplopia.