What is optic chiasm compression?

When there is compression at optic chiasm, the visual impulse from both nasal retina are affected, leading to inability to view the temporal, or peripheral, vision. This phenomenon is known as bitemporal hemianopsia.

What will result from pressure to the optic chiasm?

Pituitary Adenoma They can sometimes cause impaired vision. As the pituitary adenoma grows, it puts pressure on the optic nerve and the optic chiasm. This pressure compresses the nerve and causes vision impairment. It can even cause complete and permanent blindness.

What is considered a large Macroadenoma?

A macroadenoma is a usually benign tumor composed of glandular tissue growth larger than 10 mm (those under 10 mm are called microadenomas) in the pituitary gland. The term macro simply refers to its size. Macroadenomas can cause symptoms because they grow and press on nearby brain structures.

How is Macroadenoma treated?

Gonadotropin-secreting macroadenomas are treated surgically, followed by radiation. Medical therapy is reserved for those patients who decline definitive treatment. Bromocriptine or octreotide may be used. LH-releasing hormone antagonists may decrease hormone levels but do not affect the tumor size.

Is the optic chiasm a disorder or compression?

It is a normal structure in the brain, not a disorder or compression: The optic chiasm is an X-shaped structure formed by the crossing of the optic nerves in the brain. The optic nerve connects the brain to the eye. To biologists, the optic chiasm is thought to be a turning point in evolution.

Is the optic chiasm a turning point in evolution?

The optic chiasm is an X-shaped structure formed by the crossing of the optic nerves in the brain. The optic nerve connects the brain to the eye. To biologists, the optic chiasm is thought to be a turning point in evolution. I realize my question isn’t clear, if there is documentation of optic chiasm compression is it considered brain compression?

Which is the most common cause of chiasmal compression?

Among the causes of chiasmal compression, pituitary adenomas are the most frequent benign tumors. In the parasellar region, meningiomas can compress both the chiasm and the optic nerves and invade the surrounding anatomical structures such as the cavernous sinus ( Schiefer et al., 2004 ).

Where is the optic chiasm located in the pituitary gland?

The optic chiasm is located directly over the pituitary gland in 80% of individuals. The rest are divided between pre and postfixed chiasms. A prefixed optic chiasm is located anterior to its normal position over the tuberculum sellae, whereas a postfixed chiasm is located over the dorsum sellae 10.