Background and objective: Only limited volume expansion is offered by traditional lateral orbital decompressions in which the anterior segment of the lateral wall is removed to allow lateral soft tissue prolapse. A great deal of additional soft tissue expansion can be obtained, not only laterally, but also posteriorly by removing the deep portion of the sphenoid wing. The authors report their experience in removing this bone through a coronal approach.
Patients and methods: The authors performed maximal, three-wall, orbital decompressions through a coronal approach for 20 patients with thyroid-related orbitopathy. A disfiguring proptosis resulting from stable Graves' disease orbitopathy was the indication for surgery in all cases. Through a coronal approach, the lateral rim was left in place and thinned, augmented with specialized orbital rim onlay implants, or repositioned with osteosynthesis systems. The bone over the lacrimal fossa was sculpted to form a "keyhole" for the lacrimal gland, thereby providing additional orbital expansion. Once the medial canthal tendon and lacrimal sac had been elevated from their periosteal attachment, excellent exposure was obtained for medial and inferior orbital decompression.
Results: The authors report the results of 20 coronal orbital decompressions during a period of 44 months. Seven cases included lateral rim advancement. Up to 6 mm of retrodisplacement was achieved without rim augmentation, 9 mm with rim augmentation.
Discussion: The deep lateral orbital wall can provide significant room for volume expansion. The authors found that up to 6 mm of proptosis reduction can be obtained using the lateral wall alone. The coronal approach provides access to all four orbital walls for deep orbital decompression. The authors' philosophy of treatment in cases without compressive optic neuropathy is evolving toward the use of the lateral wall as the first approach with the incorporation of additional walls as needed.