Graded Decompression of Orbital Fat and Wall in Patients with Graves' Orbitopathy

PURPOSE To investigate the results of graded decompression of orbital fat and walls in Graves' orbitopathy (GO) considering the degree of proptosis reduction at surgery and preoperative computed tomography (CT) findings. METHODS This is a retrospective interventional case series. Graded orbital fat and wall decompression was performed in 90 orbits of 55 patients. In patients with enlarged extraocular muscles and minimal orbital fat proliferation in preoperative CT scans, one- or two-wall decompression of posterior orbit was performed with minimal fat excision. In other cases, the maximal amount of fat tissue was removed from the post-septal area to the apex. If the proptosis was not satisfactorily symmetrically reduced at surgery, one- or two-wall decompression was performed successively. Symmetric reduction of proptosis was consistently confirmed intraoperatively to assure that a desired amount of exophthalmos reduction was achieved. RESULTS FOUR TYPES OF DECOMPRESSION WERE PERFORMED: fat only (group 1), fat and one-wall (group 2), fat and two-wall (group 3), and two-wall and minimal fat decompression (group 4). The mean preoperative Hertel value (20.6 ± 2.8 mm) was reduced significantly at six months postoperatively (16.1 ± 2.3 mm). Proptosis significantly decreased with a mean of 4.3 ± 1.7 mm, and the reduction was greatest (5.1 ± 2.1 mm) in group 3. In group 1, a significant correlation between Hertel change and the volume of resected orbital fat was found (r = 0.479). Diplopia was newly developed or aggravated postoperatively in eight patients, and six of these patients were in group 3. With the exception of one patient, visual acuity improved to nearly normal postoperatively in all patients with optic neuropathy. CONCLUSIONS Graded orbital decompression of orbital fat and bony walls, as assessed by the degree of proptosis reduction during surgery, was effective and predictable with minimal complications in GO patients with vision-threatening or cosmetically disfiguring proptosis.