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Bitemporal hemianopsia is the medical description of a type of partial blindness where vision is missing in the outer half of both the right and left visual field. It is usually associated with lesions of the optic chiasm , the area where the optic nerves from the right and left eyes cross near the pituitary gland.
Visual field-bitemporal hemianopia Visual field-binasal hemianopia. A lesion involving complete optic chiasm, which disrupts the axons from the nasal field of both eyes, causes loss of vision of the right half of the right visual field and the left half of the left visual field. [3] This visual field defect is called as bitemporal hemianopia.
This leads to a smaller, paracentral bitemporal field loss. Because the temporal macular fibers have not been damaged, it is possible to preserve color vision and visual acuity. Posterior lesions may also involve the optic tract and cause a contralateral homonymous hemianopia.
Paris as seen with left homonymous hemianopsia. A homonymous hemianopsia is the loss of half of the visual field on the same side in both eyes. The visual images that we see to the right side travel from both eyes to the left side of the brain, while the visual images we see to the left side in each eye travel to the right side of the brain.
Confrontation visual field testing is an important part of a routine ophthalmological or neurological examination. It can be used for rapid and gross assessment of large-scale visual field problems due to ophthalmological or neurological diseases, such as homonymous and heteronymous hemianopias, quadranopsia, altitudinal visual loss, central/centrocecal scotoma etc. [1] [2] Test using a red ...
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.
The visual field of each eye can be divided in two vertically, with the outer half being described as temporal or lateral, and the inner half being described as nasal. "Binasal hemianopsia" can be broken down as follows: bi-: involves both left and right visual fields; nasal: involves the nasal visual field; hemi-: involves one-half of each ...
Figure 1 - Humphrey field analyser. Humphrey field analyser (HFA) is a tool for measuring the human visual field that is commonly used by optometrists, orthoptists and ophthalmologists, particularly for detecting monocular visual field. [1] The results of the analyser identify the type of vision defect.