Bitemporal Hemianopsia
Type: Symptom
Definition
A partial blindness where vision is missing in the outer half of both the right and left visual fields.
Clinical Details
The pituitary gland sits in a tight bony cradle directly beneath the optic chiasm, where the optic nerves cross. If a prolactinoma grows large enough (a macroadenoma), it expands upward and physically compresses the optic chiasm. This compression specifically damages the nerve fibers responsible for peripheral vision, causing a distinct 'tunnel vision' effect.