A four-wall orbital decompression for dysthyroid orbitopathy.

A new surgical technique is described for the relief of the ocular manifestations of dysthyroid orbitopathy. Surgical decompression of the orbit was reserved for patients who failed to respond to medical treatment. Eleven patients (nine women and two men) were followed for periods from 3 to 48 months. Visual loss was the commonest presentation and the main indication for surgery. All patients had failed to respond to medical therapy, consisting of steroid and/or radiation therapy. Three patients had previously undergone orbital decompressions with limited success. Six patients had preoperative visual acuity of worse than 20/200. Preoperative exophthalmos ranged from 24 to 35 mm (normal 16 mm). The orbits were approached by a bifrontal scalp flap with exposure of the temporal and infratemporal fossae. The orbital roof was approached transcranially. The posterior wall of the frontal sinus was removed together with the mucous lining. To maximize the decompression, the periosteum surrounding the orbital contents was incised, allowing the contents to prolapse through the newly created windows into the maxillary antrum, temporal fossa, anterior cranial fossa, and nose. During the past 3 years, 22 orbits in 11 patients have been decompressed by this technique. Symptomatic relief was obtained in all but one patient who still had significant exophthalmos with keratitis, but did have a dramatic improvement in vision. The decrease in exophthalmos ranged from 1 to 13 mm (mean 7 mm). The most dramatic improvement was in vision, with postoperative acuity of 20/20 to 20/30 in all but two patients. There were no deaths and no major morbidity.