Endoscopic orbital surgery has rapidly established itself as a highly evolving multidisciplinary surgical field, relying on the expertise and technical skills of ophthalmologists and otolaryngologists. In 1978, Norris and Cleasby first described the use of the endoscope for orbital surgery in the ophthalmic literature. Three years later, in 1981, they reported a 15-patient case series describing their experience using a transorbital endoscopic approach for orbital trauma evaluation, foreign body removal, and tumor biopsy. The adoption of transorbital endoscopic surgery by the ophthalmic community was limited owing to risks of irrigation-related intraorbital pressure elevation, tissue edema, and compressive injury. As a result, most ophthalmologists and oculofacial surgeons use endoscopic techniques mainly when performing endoscopic dacryocystorhinostomies ( Fig. 2.1 ) and endoscopic brow lifts.
In contrast, the introduction of endoscopic surgery in the field of otolaryngology has revolutionized the treatment of sinus and allergic disease. The widespread use of the endoscopic transnasal approach has resulted in rapid development and implementation of technological innovations. These advances have led to an expansion of the clinical utility of the transnasal endoscopic approach, with a variety of applications addressing pathology and disease in the adjacent anatomic regions, including the skull base and orbit.
In particular, there has been a tremendous increase in the otolaryngology literature describing the endoscopic transnasal orbital decompression technique in the management of thyroid eye disease and compressive optic neuropathy. In 1990, Kennedy et al. introduced the transnasal endoscopic approach for orbital decompression. In this study, they reported a mean improvement in Hertel exophthalmometry measurements of 4.7 mm in five patients after medial and inferior wall decompression using this transnasal endoscopic technique. Since then, several modifications to this approach have been described to improve outcomes and decrease complication risks. For example, the incidence of new-onset diplopia in early reports of endoscopic decompressions occurred in up to 45% of cases. However, preservation of the inferomedial orbital bone strut in endoscopic orbital decompression has resulted in a tremendous reduction in new-onset postoperative diplopia. Aside from the improvement in patient outcomes, this modification highlights the importance of an established interdisciplinary relationship and collaboration between the oculoplastic surgery and otolaryngology fields, as this technique was adopted from the work described by Goldberg, Shorr, and Cohen in the oculoplastic surgery literature in 1992. The anatomic expertise of both fields has improved our understanding of the orbital strut and suspensory ligament complex and the sinus anatomy to preserve the position of the globe after endoscopic surgery. Furthermore, the preservation of a strip of the periorbita medial to the medial rectus muscle has also been introduced to limit medial rectus muscle prolapse into the ethmoid cavity. This “orbital sling” technique is an additional modification that can be used to improve the versatility of the transnasal endoscopic approach for orbital decompression.
The growing use of the endoscopic approach for orbital decompressions in the surgical management of thyroid eye disease has fostered a strong relationship between the ophthalmologist and otolaryngologist. In 1993, one author (J.B.H.) began a collaborative relationship for orbital decompression to achieve a lower risk of complications and improve patient care and safety. In 1999, Graham and Carter described the combined-approach orbital decompression as a safe, efficient, and efficacious joint service procedure, wherein the otolaryngologist performed the endoscopic medial wall decompression and the ophthalmologist completed the external, transorbital inferior, and lateral wall decompressions. This collaborative effort leverages the advantageous features of each approach. The endoscopic approach provides improved visualization of the posterior medial wall, limiting the potential for surgical optic nerve injury and maximizing the extent of decompression at the orbital apex. These advantages are of particular importance in cases requiring decompression for progressive thyroid disease–related optic neuropathy. The external, transconjunctival, and lateral canthal approach provides direct visualization of the infraorbital nerve to enable extensive inferior wall decompression, both medial and lateral to the infraorbital nerve. Additionally, the simultaneous three-wall decompression facilitates maximal reduction in exophthalmos in a single operation, while also reducing the incidence of postoperative diplopia owing to the balancing effect when both the medial and lateral walls are decompressed.
The remarkable advances in endoscopy in the past decades have introduced additional team-based surgical opportunities for the otolaryngologist and ophthalmologists. Specifically, several recent studies have highlighted the benefits of a combined procedure with complex posterior and apical orbital masses. Curragh, Halliday, and Selva described the potential utility of a dual-route technique wherein the orbital apical mass is accessed via a transnasal endoscopic approach and a transcaruncular orbitotomy is simultaneously used to assist in manipulation and removal of the mass. Additionally, they describe the advantageous incorporation of an external transconjunctival disinsertion of the medial rectus muscle to increase endoscopic exposure during orbital biopsies and excisions, which can be reinserted at the conclusion of the procedure.
Surgical navigation and localization is an area of rapid progress and evolution that enhances patient safety and surgical outcomes. These systems also play an integral role in robotic surgery. Initially used in neurosurgery and otolaryngology for localization in areas of critical anatomy or to allow for small incision approaches, these systems have been adopted in ophthalmology and oculofacial surgery to enhance patient safety ( Fig. 2.2 ). Several reports in the ophthalmic plastic surgery literature highlight the utility of stereotactic image guidance systems as adjunctive tools in orbital tumor excisions and orbital decompressions.
