title: Endoscopic endonasal optic nerve and orbital apex decompression for nontraumatic optic neuropathy: surgical nuances and review of the literature.
abstract: OBJECTIVE
  While several approaches have been described for optic nerve decompression, the endoscopic endonasal route is gaining favor because it provides excellent exposure of the optic canal and the orbital apex in a minimally invasive manner. Very few studies have detailed the experience with nontraumatic optic nerve decompressions, whereas traumatic cases have been widely documented. Herein, the authors describe their preliminary experience with endoscopic endonasal decompression for nontraumatic optic neuropathies (NONs) to determine the procedure's efficacy and delineate its potential indications and limits.
  
  
  METHODS
  The medical reports of patients who had undergone endoscopic endonasal optic nerve and orbital apex decompression for NONs at the Lyon University Neurosurgical Hospital in the period from January 2012 to March 2014 were reviewed. For all cases, clinical and imaging data on the underlying pathology and the patient, including demographics, preoperative and 6-month postoperative ophthalmological assessment results, symptom duration, operative details with video debriefing, as well as the immediate and delayed postoperative course, were collected from the medical records.
  
  
  RESULTS
  Eleven patients underwent endoscopic endonasal decompression for NON in the multidisciplinary skull base surgery unit of the Lyon University Neurosurgical Hospital during the 27-month study period. The mean patient age was 53.4 years, and there was a clear female predominance (8 females and 3 males). Among the underlying pathologies were 4 sphenoorbital meningiomas (36%), 3 optic nerve meningiomas (27%), and 1 each of trigeminal neuroma (9%), orbital apex meningioma (9%), ossifying fibroma (9%), and inflammatory pseudotumor of the orbit (9%). Fifty-four percent of the patients had improved visual acuity at the 6-month follow-up. Only 1 patient whose sphenoorbital meningioma had been treated at the optic nerve atrophy stage continued to worsen despite surgical decompression. The 2 patients presenting with preoperative papilledema totally recovered. One case of postoperative epistaxis was successfully treated using balloon inflation, and 1 case of air swelling of the orbit spontaneously resolved.
  
  
  CONCLUSIONS
  Endoscopic endonasal optic nerve decompression is a safe, effective, and minimally invasive technique affording the restoration of visual function in patients with nontraumatic compressive processes of the orbital apex and optic nerve. The timing of decompression remains crucial, and patients should undergo such a procedure early in the disease course before optic atrophy.
authors.affiliation: Skull Base Surgery Unit, Department of Neurosurgery B, Pierre Wertheimer Neurological and Neurosurgical Hospital, Hospices Civils de Lyon.
authors.forename: Moncef
authors.initials: M
authors.lastname: Berhouma
authors.forename: Timothee
authors.initials: T
authors.lastname: Jacquesson
authors.forename: Lucie
authors.initials: L
authors.lastname: Abouaf
authors.forename: Alain
authors.initials: A
authors.lastname: Vighetto
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Jouanneau
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D019299:Decompression, Surgical / Q000379:methods*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D009901:Optic Nerve Diseases / Q000150:complications / Q000601:surgery*; D009915:Orbit / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D014786:Vision Disorders / Q000209:etiology / Q000601:surgery
keywords: NON= nontraumatic optic neuropathy; TOF = time-of-flight; endoscopie endonasal surgery; minimally invasive neurosurgery; optic nerve decompression; optic neuropathy; orbital tumors; skull base surgery