[Indications and technique of optic nerve sheath fenestration]

[Indications and technique for transconjunctival optic nerve sheath fenestration : Video article]

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.

[Therapy of tumors of the anterior orbit]

Tumors of the orbit are diagnosed on clinical and neuroradiological criteria. A biopsy may histologically confirm uncertain mass lesions. The patients' age and medical history predispose for certain tumor entities among the rather heterogenous spectrum of possible diagnoses. The therapy depends on the degree of malignancy and its location within the orbit. Among the different options, surgical excision is the most common followed by radiation therapy either in combination with surgery or alone. Chemotherapy plays a subsidiary role in certain lymphomas or metastases. This review covers the surgical techniques and treatment principles for tumors of the anterior orbit, explains radiotherapy techniques and briefly covers chemotherapy. Pediatric tumors of the orbit are covered separately.