Orbital decompression: cadaver study.

Abstract

BACKGROUND: Patients with Graves' ophthalmopathy may need surgical treatment to alleviate ophthalmologic complications. The degree of reduction in proptosis following surgical intervention remains difficult to predict. OBJECTIVES: To elaborate a human model using cadaver orbits to study surgical management of Graves' ophthalmopathy. To evaluate quantitatively the contribution of each orbital wall decompression and their combinations in reduction in proptosis. To improve the ability to predict the degree of proptosis reduction according to the wall(s) chosen for decompression. METHODS: Artificial exophthalmos was created in 12 cadavers' orbits by injecting a polysaccharide gel in the peribulbar and retrobulbar tissues. Proptosis reduction was measured following successive orbital decompression. RESULTS: Decompression of one wall produced a nonstatistical significant reduction in proptosis. The combination of the medial and lateral walls significantly reduced the proptosis by a mean of 4.2 mm. Three-wall decompression gave a mean significant reduction of 6.6 mm, and when combined with the advancement of the lateral wall, it reduced proptosis by 12.5 mm. CONCLUSIONS: We created an experimental model for research and didactic purposes for surgical mangement of Graves' ophthalmopathy. With this model, to obtain 5 mm or more of proptosis reduction, three-wall decompression is required. Advancement of the lateral wall achieved a further reduction in proptosis. For a proptosis reduction of less than 5 mm, decompression of the medial and lateral walls is appropriate.