The visual field of each eye can be divided in two vertically, with the outer half being described as temporal, and the inner half being described as nasal.
In binasal hemianopsia vision is missing in the inner half of both the right and left visual fields.
Binasal hemianopsia can be broken down as follows:
- bi-: involves both left and right visual fields
- nasal: involves the nasal visual field
- hemi-: involves half of each visual field
- anopsia: blindness
The temporal visual field falls on nasal retina and the nasal visual field falls on temporal retina. When there is compression at optic chiasm the visual impulse from oth nasal retina affected. Nasal retina is responsible for temporal visual field so it leads to bitemporal hemianopsia. Knowing the physiology of visual signal flow is very impotant in understandng bitemporal hemianopsia.
|This page uses Creative Commons Licensed content from Wikipedia (view authors).|