Bitemporal Hemianopsia Meaning, Symptoms, Causes, Diagnosis, Treatment

Bitemporal hemianopsia is also known as bitemporal hemianopia and bitemporal heteronymous hemianopsia. Bi means “both left and right side”, temporal means “temporal visual field”, hemi means “half of each visual field”and anopsia means “blindness”. It is the type of half or partial blindness in which half of the vision is lost from the both outer sides of the eye. The visual information obtained from temporal side falls on the medial (nasal) retina. Information from the optic nerve is transferred to the optic chiasm via nasal retina.

The vision is effected when there is compression at the optic chiasm. Due to compression the impulses generating from both the nasal retina are effected and as a result both the temporal and peripheral vision is affected. This is the common visual defect occurring. Basically occurs when there is compression or destruction of the optic nerve. In this condition only the central visuality remains active and this central field is enough to have a wide or clear vision. In a way, the central vision is okay the bitemporal hemianopsia don’t disturbs the regular routine activities of life. The patient is not able to use images properly and then the symptoms arise.

Bitemporal Hemianopsia Causes

The most common cause reported yet for bitemporal hemianopsia is trauma. The trauma at mid optic nerve. Also the compression of optic chiasm causes the disturbance in vision as the impulses can’t transfer due to site compression. The nearest gland located is known as pituitary gland so any kind of trauma at pituitary gland like pituitary adenomas and craniopharyngiomas can also be the cause to this condition. Other causes include the neoplastic trauma like meningioma (it is the tumor at the meningeal tissue of brain). Whenever there is compression of chiasm the communicating artery may show aneurysm.

Bitemporal Hemianopsia Symptoms

• Patient cannot move willingly in the crowded areas and may not have proper vision.
• Patient may fall due to bumps in different places of pathway.
• The patient may not sure about his/her footsteps and may fall or stumble.
• The patient may not read properly from books and internet and become frustrated when he loses the sentence or a word and can’t find it.
• The patient may have difficulty during eating and drinking
• The patient can’t maintain his body balance during walking or running 
• Dizziness is also reported.
• Patient may feel fear and stress during any activity.
• Panic attacks in crowded areas. 

Bitemporal Hemianopsia Diagnosis

There are some procedures used or the diagnosis of bitemporal hemianopsia like

• Visual field testing: in this testing the lesions on the optic nerve chiasm is confirmed. visual field testing always done before surgery.
• Any kind of lesion or defect on pituitary gland is observed with the neuroimaging. MRI’s and high resolution CT scans are also helpful in diagnosing the cause of bitemporal hemianopsia. MRI test is more accurate as compare to CT scan.
• Some laboratory tests are also performed to check the performance of endocrine glands. As endocrine gland working will ultimately show the working of pituitary gland.

Bitemporal Hemianopsia Treatment

             
There is not a proper treatment or cure for bilateral hemianopsia but there may the surgical removal of the tumor located on pituitary gland.

• The patient may wear goggles while going outside.
• Audiovisual stimulation technique helps in stimulating the vision of patient.
• Visual restoration therapy is also effective.
• Explorative saccade training in which the patient is encouraged to look around and check the area of visual absence.
• Optical visual span expanders improve the vision of the patient.
• The associated problems are also treated to like difficulty in speech, paralysis, partial memory loss and emotional disturbances may occur.