Why does pituitary tumor cause bitemporal hemianopia?

A pituitary tumor frequently causes bitemporal hemianopia by compressing the optic chiasm initially. Visual field defects are thought to be due to the direct compression or the effect on the blood supply of the optic chiasm.

What causes a bitemporal hemianopia?

A bitemporal hemianopia is almost always caused by damage to the optic chiasm and can occur from the direct or indirect effects of a variety of lesions, including tumors,1 aneurysms,2 and, less frequently, inflammatory and ischemic diseases.

What is Heteronymous Hemianopsia?

Heteronymous hemianopia. This is the area in your brain where the optic nerves cross and form an “X.” The two types of heteronymous hemianopia are bitemporal and binasal. Bitemporal hemianopia is when you lose vision in the outer half of each eye.

How do you treat bitemporal hemianopia?

Surgery

Surgery is the mainstay of treatment for bitemporal hemianopia.
Pituitary adenoma: Transsphenoidal pituitary surgery is the first line surgery for pituitary adenomas. Visual improvement occurs in 87% of those with preoperative visual loss. It has a mortality rate of 0.5%.

Which nerve is affected in pituitary tumor?

Pituitary apoplexy appears to be the primary cause of cranial nerve palsy with pituitary tumour. Early surgical intervention is most likely to bring about rapid recovery from cranial nerve dysfunction.

Can a pituitary tumor be seen in an eye exam?

If a pituitary tumor is strongly suspected, your doctor may refer you to an eye doctor to check your vision, as pituitary tumors can damage nerves leading to the eyes. The most common test is to measure how well you can see. The doctor may also test your field of vision (or visual fields).

What is meant by bitemporal hemianopia?

Bitemporal hemianopsia (or bitemporal hemianopia) describes the ocular defect that leads to impaired peripheral vision in the outer temporal halves of the visual field of each eye.