Endoscopic Endonasal Decompression of the Medial Orbit and Optic Canal: A Retrospective Analysis

Background: With advances in endoscopic surgical techniques, endonasal decompression of the medial orbit and optic canal for compressive optic neuropathies is occurring more frequently. In the past, there has been debate in the literature regarding the capacity of this procedure to adequately decompress the optic nerve, primarily due to its inability to unroof the optic canal or resect the intracanalicular portions of skull base tumors. Our objective in the present study is to review the outcomes, in terms of preservation and restoration of visual function, of patients who have undergone endoscopic endonasal optic nerve decompression, and to compare those outcomes to patients undergoing open cranial procedures.

Methods: We retrospectively reviewed the records of patients who underwent procedures which involved either open cranial or endoscopic endonasal decompression of the orbit, optic canal, or cavernous sinus. All procedures were performed by either the neurosurgery service, or jointly between the neurosurgery and otolaryngology services at our institution between 2010 and 2014. We evaluated visual function pre-operatively, in the immediate post-operative period, and at follow-up. All patients had a minimum follow-up period of 6 months. Primary outcomes measured were improvement, preservation, or decline of visual function. Secondary outcomes included the response of other cranial neuropathies to surgery, long-term tumor control, and quality of life measures.

Results: The patients in our study underwent treatment for several pathologies, including a variety of skull base neoplasms and inflammatory disorders. Most common were tuberculum, planum, and spheno-orbital meningiomas. Patients undergoing endoscopic procedures had results which were comparable to those who had open transcranial surgery, with a similar rate of improvement in visual function, as well as long-term preservation. Quality-of-life measures were generally higher in the endoscopic group. Rates of significant procedure-related complications were similar between the two cohorts.

Discussion: In our experience, endoscopic endonasal decompression of the medial orbit and optic canal is at least as safe and effective as traditional open surgery, with the added benefits of a less invasive procedure. Consideration should be given to this approach in cases of nontraumatic compressive optic neuropathies, and we anticipate its use will become more widespread as advancements in endoscopic skull base surgery continue.