What Is Optic Nerve Glioma?

Optic gliomas are benign tumors that occur in the glial cells in the optic nerve and can spread to the skull along the optic nerve. It is more common in preschool children, rare in adults, partly associated with neurofibromatosis, and suspected of genetic predisposition. The prognosis is better than intracranial glioma.

Basic Information

Visiting department

Oncology

Multiple groups

Preschool children

Common causes

Neurofibromatosis

Common symptoms

Slow vision loss, protruding eyeballs, disc edema and atrophy, fundus bleeding, etc.

Clinical manifestations of optic glioma

1. Blind spots in the visual field appear early and gradually lose vision to vision loss. The pupil dilates concentrically and the relative pupil afferent block.

2. Eyeball protrusion is painless and slowly progressive. Such as sudden increase in eyeball protrusion, accompanied by vision loss, suggesting cystic changes or bleeding within the tumor.

3. Fundus examination: Optic disc edema and atrophy are more common, and secondary fundus hemorrhage may occur.

4. Some patients may have signs of neurofibromatosis such as pale yellow nodules of the iris, coffee-like pigmented spots on the skin, and soft masses under the skin.

Diagnosis of optic glioma

1.X-ray

It can be found that the tumor spreads through the optic canal into the skull. Long-term chronic compression can cause the optic nerve tube to expand concentrically. Optic tube imaging can show this change.

2. Ultrasound

B-ultrasound showed that the optic nerve was thickened, and the internal echo was lacking or scarce. Axial scanning could not show the posterior boundary, and the echo of the tilted probe increased.

3.CT scan

The optic nerve is fusiform or tapered and can push the eyeball forward or to one side. The boundaries are clear. The intratumoral density is more uniform. If it is heterogeneous, a liquefaction zone is suspected. The optic canal is thickened and suspicious tumor has intracranial spread.

4.MRI scan

T ₁ WI showed a medium signal, and T ₂ WI showed a medium and high signal. If there is a liquefied cavity in the tumor, it is not enhanced.

Differential diagnosis of optic glioma

Optic nerve sheath meningiomas

Adults are prone to slow vision loss. Imaging can find that the optic nerve is thickened and has various shapes, such as tubular, spindle-shaped, cone-shaped, bead-like, lumpy or irregular. Because the tumor originated from the optic nerve sheath, both CT and MRI showed a "car rail sign."

2. Congenital small eyeball with cyst

Visits in childhood. Non-functional small eyeballs are often hidden under the eyelids. Under the slit lamp, abnormal eyeball development is seen, and the structure is absent. Protrusion of the cyst can cause periorbital bulge. Imaging can find cystic mass behind the small eyeball, which is round, oval or conical.

3. Peripheral optic inflammatory pseudotumor

Eye inflammation, conjunctival congestion and other inflammation manifestations are obvious, and hormone therapy is effective. Imaging can find irregular shapes occupying around the optic nerve, and the boundaries are unclear. The forward development surrounds the eyeball and presents a "casting sign."

Optic Glioma Treatment

1. Good vision, not prominent eyeballs, slow progress, imaging shows that tumors far from the optic canal can be observed regularly. It has been reported that the disease resolves on its own, for unknown reasons.

2. The visual acuity is lower than the index, the eyeballs are prominent, and those with local tumors in the orbit can perform lateral orbital resection to remove the tumor. Optic nerve stump can still be treated with X-knife or -knife.

3. Tumors that invade the optic nerve or optic cross of the inner tube can be resected through the craniotomy of the tumor before the optic cross. Violation of contralateral or bilateral lesions is feasible for radiation therapy.