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Hemianopsia, or hemianopia, is a loss of vision or blindness in half the visual field, usually on one side of the vertical midline. The most common causes of this damage are stroke , brain tumor , and trauma.
Homonymous hemianopsia can be congenital, but is usually caused by brain injury such as from stroke, trauma, [5] tumors, infection, or following surgery. Vascular and neoplastic (malignant or benign tumours) lesions from the optic tract, to visual cortex can cause a contralateral homonymous hemianopsia. Injury to the right side of the brain ...
Bitemporal hemianopsia most commonly occurs as a result of tumors located at the mid-optic chiasm. Since the adjacent structure is the pituitary gland, some common tumors causing compression are pituitary adenomas and craniopharyngiomas. Also, another relatively common neoplastic cause is meningiomas.
Lesions in that pathway cause a variety of visual field defects. In the visual system of human eye , the visual information processed by retinal photoreceptor cells travel in the following way: Retina → Optic nerve → Optic chiasma (here the nasal visual field of both eyes cross over to the opposite side)→ Optic tract → Lateral ...
Binasal hemianopsia is the medical description of a type of partial blindness where vision is missing in the inner half of both the right and left visual field. It is associated with certain lesions of the eye and of the central nervous system , such as congenital hydrocephalus .
Macular sparing can be determined with visual field testing.The macula is defined as an area of approximately + 8 degrees around the center of the visual field. [3] During examination, vision in an area of greater than 3 degrees must be preserved for a patient to be considered to have macular sparing because there is involuntary eye movement within 1 to 2 degrees.
Nelson's syndrome is a disorder that occurs in about one in four patients who have had both adrenal glands removed to treat Cushing's disease. [1] In patients with pre-existing adrenocorticotropic hormone ()-secreting pituitary adenomas, loss of adrenal feedback following bilateral adrenalectomy can trigger the rapid growth of the tumor, leading to visual symptoms (e.g. bitemporal hemianopsia ...
The stroke for this disorder occurs in the right hemisphere of the brain. Other etiologies that cause right hemisphere damage include: trauma (traumatic brain injury), disease, seizures disorders, and infections. Depending on the etiology that causes the right hemisphere damage, different deficits can be accounted for. [20] "The level of ...