ORBITAL FAT REMOVAL - DECOMPRESSION FOR GRAVES ORBITOPATHY

Background: Orbital decompression has been used to describe surgical p rocedures that remove some portion of the orbital walls to reduce pres sure on the orbital contents. Substantial morbidity associated with th ese procedures includes infraorbital anesthesia, worsened extraocular motility, globe displacement, and blindness. The authors believe that orbital contents also may be decompressed by removing orbital fat. Met hods: Eighty-one patients with nonactive Graves orbitopathy were selec ted for orbital fat decompression based on the presence of proptosis a nd associated signs and symptoms to avoid bone removal. Soft-tissue an alysis by computed tomography (CT) scan showed distended pockets of fa t extending into the intraconal space, which were removed through medi al-upper and lateral-lower anterior orbitotomies. Decompression with b one removal was reserved for those few patients with compressive optic neuropathy unresponsive to medical treatment and those patients with residual deforming exophthalmos after fat removal. Results: One hundre d fifty-eight fat decompressions were performed on 81 patients over 9 years. The authors measured an average reduction in proptosis of 1.8 m m (range, 0-6.0 mm). The greatest average reduction in proptosis (3.3 mm) was produced in patients with preoperative Hertel measurements of greater than 25.0 mm. Morbidity was limited to temporary motility impa irment of the inferior oblique in two patients. Conclusion: The concep t of orbital decompression can include removal of orbital fat to reduc e proptosis, eliminate symptoms, and improve appearance with far less morbidity than when bone decompression is used as the primary decompre ssive procedure.