Horner syndrome refers to the combination of a constricted pupil, drooping eyelid, and loss of sweating around the affected eye. Vision loss, even total blindness in one eye, does not cause anisocoria. Disorders outside the brain that affect the sympathetic nervous system include tumors and injuries that involve the neck or upper part of the chest. Anisocoria (unequal pupils) is caused by unequal pupillary motor inputs to the two eyes. Brain disorders that can affect these pathways include strokes, brain hemorrhage (spontaneous or due to head injury), and, less commonly, certain tumors or infections. Thus, people with nervous system disorders that affect the pupil often also have a drooping eyelid, double vision, and/or visibly misaligned eyes. These pathways carry nerve impulses to the pupil and to the muscles that control the eye and eyelid.
Only a well-trained ophthalmologist can distinguish between these different types of damage. A direct blow to the eye can cause damage to the pupil and optic nerve independent of the brain- this is common. This system works automatically (autonomously), without a person’s conscious. Direct injuries to the eye and orbit (tissue around the eye) can effect pupillary measurement. Occasionally, the two pupils can appear unequal in size. Nervous system disorders that cause unequal pupils are those that affect the 3rd cranial nerve or certain parts of the sympathetic or parasympathetic nervous system (the autonomic nervous system Overview of the Autonomic Nervous System The autonomic nervous system regulates certain body processes, such as blood pressure and the rate of breathing.
0 kommentar(er)
