Related Experiment Video
Updated: Feb 23, 2026

Transconjunctival Approach for Injection into the Rat Optic Nerve
Published on: April 4, 2025
[Indications and technique for transconjunctival optic nerve sheath fenestration : Video article]
W A Lagrèze1, N Gross2, J Biermann2
1Klinik für Augenheilkunde, Medizinische Fakultät, Universität Freiburg, Killianstr. 5, 79106, Freiburg, Deutschland. wolf.lagreze@uniklinik-freiburg.de.
Background:
Placement of a ventricular shunt is the primary surgical procedure for lowering intracranial pressure in pseudotumor cerebri syndrome; however, if ophthalmological symptoms prevail over neurological symptoms or if there are no neurological symptoms at all, optic nerve sheath fenestration may be a valuable option for relief of pressure on the retrobulbar optic nerve when papilledema caused by pseudotumor cerebri syndrome threatens vision despite previous conservative measures.
Methods:
This review covers the indications, technique and results of optic nerve sheath fenestration compared to competing procedures based on a systematic literature search, analysis of own cases and a documentation of the surgical technique.
Surgical Technique:
After performing a medial transconjunctival orbitotomy the medial rectus muscle tendon is temporarily detached and the eye abducted by traction sutures. Using confocal illumination under a surgical microscope, the optic nerve can be visualized using orbital spatulas and the sheath can be punctured with a microscalpel. A video of this operation is available online.
Conclusion:
Transconjunctival optic nerve sheath fenestration is a relatively safe method to reduce the rate of visual loss in pseudotumor cerebri syndrome. In selected cases it can be a useful alternative to ventriculoperitoneal/atrial shunts or venous stents.
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