Special Surgical Techniques in the Orbit
Fine-needle aspiration biopsy (FNAB) may have value in selected cases, including lymphoid lesions, secondary tumors invading the orbit from the sinuses, suspected metastatic tumors, and blind eyes with optic nerve tumors (Fig 7-12). This technique is not very effective for obtaining tissue from fibrous inflammatory lesions because of the difficulty in successfully aspirating cells. Although historically FNAB has not been considered effective for biopsy in lymphoproliferative disorders, technological advances have improved its diagnostic yield when used in combination with flow cytometry and monoclonal antibodies or polymerase chain reaction analysis. If necessary, imaging techniques, such as ultrasonography or computed tomography, can be used to help guide the needle into the tumor. Cells (and occasionally a small block of tissue) are aspirated from the lesion. A skilled cytologist is required to study the specimen. See BCSC Section 4, Ophthalmic Pathology and Intraocular Tumors, for further discussion of FNAB.
Because of the anatomic relationship of the ethmoid and maxillary sinuses to the medial and inferior orbit, respectively, endoscopic transnasal surgery may be considered. Such an approach may permit biopsy and/or resection of some intraconal pathology. It may also be combined with open orbitotomy to allow improved access to apical processes. In addition, decompression of the orbit or optic canal may be considered for patients with TED or nontraumatic compressive optic neuropathy. Such an approach can also be used for drainage of medial subperiosteal orbital abscesses in patients with sinusitis or for debridement of necrotic tissue in patients with fungal orbital cellulitis.
Tumors and traumatic injuries of the skull base may involve the superior and posterior orbit. Advanced surgical techniques allow access to these areas via a frontal craniotomy or frontotemporal-orbitozygomatic (FTOZ) approach. Such procedures require a multidisciplinary team. The neurosurgeon provides the orbital surgeon with unparalleled access to the deep superior and lateral orbit by removing the frontal bar and the orbital roof. These techniques enable the decompression of the optic canal, as well as resection of tumors such as meningiomas, fibrous dysplasia, cavernous venous malformations, solitary fibrous tumors, schwannomas, and gliomas.
Figure 7-12 Fine-needle aspiration biopsy (FNAB). A, Coronal computed tomography image of a left extraconal superomedial orbital mass (asterisk).B, FNAB is performed to avoid significant blood loss from an open biopsy and reveals metastatic hepatocellular carcinoma.
(Courtesy of M. Reza Vagefi, MD.)
Wiktorin ACH, Dafgård Kopp EME, Tani E, Söderén B, Allen RC. Fine-needle aspiration biopsy in orbital lesions: a retrospective study of 225 cases. Am J Ophthalmol. 2016;166:37–42.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.