optic_nerve_decompression

The supraorbital approach is a minimally invasive technique and cosmetically favorable alternative to more extended approaches with longer operative times used for the management of optic nerve decompression in posttraumatic or compressive optic neuropathy from skull base pathologies extending into the OC. The relative ease of this approach provides a relatively short learning curve for developing neurosurgeons 1).

see Optic pathway glioma

Meningioma

see optic canal meningioma

Idiopathic intracranial hypertension

Several surgical treatment modalities, including lumboperitoneal or ventriculoperitoneal shunt surgery, subtemporal decompression, endovascular venous sinus stenting, optic nerve decompression (OND), were used in the management of idiopathic intracranial hypertension (IIH). Each surgical technique has different advantages and disadvantages.

Rigante et al. propose a stepwise decompression of the optic nerve (ON) through a supraorbital minicraniotomy and describe the surgical anatomy of the ON as seen through this approach.

They also discuss the clinical applications of this approach.

Supraorbital approaches were performed on 10 preserved cadaveric heads (20 sides). First, 3.5-cm skin incisions were made along the supraciliary arch from the medial third of the orbit and extended laterally. A 2 × 3-cm bone flap was fashioned and extradural dissections were completed. A 180-degree unroofing of the ON was achieved, and the length and width of the proximal and distal portions of the optic canal (OC) were measured. Results The supraorbital minicraniotomy allowed for identification of the anterior clinoid process and other surgical landmarks and adequate drilling of the roof of the OC with a comfortable working angle. A 25-degree contralateral head rotation facilitated visualization of the ON. 2).

Endoscopic

Nasal and sphenoidal anatomies determine the feasibility and risks for doing an efficient medial optic or orbit decompression. • Techniques and tools used are those developed for pituitary surgery. • A middle turbinectomy and posterior ethmoidectomy are mandatory to expose the medial wall of the orbit. • The Onodi cell is a key marker for the optic canal and must be opened up with caution. • The lamina papyracea is opened first with a spatula and the optic canal opened up by a gentle drilling under continuous irrigation from distal to proximal. • Drilling might always be used under continuous irrigation to avoid overheating of the optic nerve. An ultrasonic device can be used as well. • The nasal corridor is narrow and instruments may hide the infrared neuronavigation probe. To overcome this issue, a magnetic device could be useful. • Doppler control could be useful to locate the ICA. • The optic canal must be opened up from the tuberculum of the sella to the orbital apex and from the planum (anterior cranial fossa) to the lateral OCR or ICA canal • At the end of the procedure, the optic nerve becomes frequently pulsatile, which is a good marker of decompression 3).

Ophthalmologic factors and factors directly related to the lesion are most important in determining vision outcome. The decision to perform optic nerve decompression for vision loss should be made based on careful examination of the patient and realistic discussion regarding the probability of improvement 4).


1) , 2)
Rigante L, Evins AI, Berra LV, Beer-Furlan A, Stieg PE, Bernardo A. Optic Nerve Decompression through a Supraorbital Approach. J Neurol Surg B Skull Base. 2015 Jun;76(3):239-47. doi: 10.1055/s-0034-1543964. Epub 2015 Jan 21. PubMed PMID: 26225308; PubMed Central PMCID: PMC4433391.
3)
Jacquesson T, Abouaf L, Berhouma M, Jouanneau E. How I do it: the endoscopic endonasal optic nerve and orbital apex decompression. Acta Neurochir (Wien). 2014 Oct;156(10):1891-6. doi: 10.1007/s00701-014-2199-1. Epub 2014 Aug 22. PubMed PMID: 25143184.
4)
Carlson AP, Stippler M, Myers O. Predictive factors for vision recovery after optic nerve decompression for chronic compressive neuropathy: systematic review and meta-analysis. J Neurol Surg B Skull Base. 2013 Feb;74(1):20-38. doi: 10.1055/s-0032-1329624. Epub 2012 Nov 26. PubMed PMID: 24436885; PubMed Central PMCID: PMC3699164.
  • optic_nerve_decompression.txt
  • Last modified: 2015/11/12 13:47
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