Introduction: For excellent visualization of the optic chiasm and optic canal, the endoscopic partial transethmoidal transsphenoidal approach offers an excellent route for decompression of the optic canal for pathologies that affect these structures. In combination with medial orbitotomy opic nerve can be decompressed more laterally and even intraorbitally.
Methods: Using the standard endoscopic transnasal approach in 3 thiel-fixed cadaveric skulls (6 optic nerves), after sinus-sphenoidectomy we identified the optic canal and opticocarotid recess carefully considering the bony landmarks. After thinning and removal of bony structures over this canal, optic nerve decompression extended from the medial (sellar) part to the lateral part endoscopically. Then additionally we performed
modified killian incision and removed lamina papyracea achieving more visibility of optic nerve intraorbitally. During each step we measured the length of visualized optic nerve using flexible ruler under endoscope view and compared the
length of optic decompression with and without combined approach.(Figure 1 & 2)
Results: Our visual findings confirmed decompression of the optic nerve, extending from optic chiasm to annulus of zinn. Length of decompression included the chiasma,
intracranial part, entire intracanalicular part and intraorbital part.
Our combined approach increased the length of intraorbital decompression. Our study confirmed the efficacy of the transnasal endoscopic transsphenoidal resection in combination with medial orbitotomy in optimal optic nerve decompression particularly intraorbital part.
Conclusions: This combined approach achieved extensive bony decompression of the optic canal not only intracranially but also intraorbitally . Clinical efficacy, in terms of visual outcome requires further anatomical and clinical evaluation.
Patient Care: we quantify the extent of optic nerve decompression in a cadaveric model in combination with medial orbitotomy and highlight its effectiveness in a patient with intracranial and intraorbital compressive optic neuropathy.
Learning Objectives: Describing the steps of this transnasal endoscopic approach, we quantify the extent of
optic nerve decompression in a cadaveric model in combination with medial
orbitotomy and highlight its effectiveness in a patient with intracranial and
intraorbital compressive optic neuropathy.