What is normal pupillary reflex?
What is normal pupillary reflex?
The normal pupil size in adults varies from 2 to 4 mm in diameter in bright light to 4 to 8 mm in the dark. The pupils are generally equal in size. They constrict to direct illumination (direct response) and to illumination of the opposite eye (consensual response). The pupil dilates in the dark.
How do you assess pupillary light reflex?
Performing the Exam for Pupillary Responses
- Observe the pupil size and shape at rest, looking for anisocoria (one pupil larger than the other)
- Observe the direct response (constriction of the illuminated pupil)
- Observe the consensual response (constriction of the opposite pupil)
- Repeat with the opposite pupil.
What are the three pupillary reflexes?
It consists of a pupillary accommodation reflex, lens accommodation reflex, and convergence reflex. Afferent pathway for pupillary constriction, lens accommodation, and convergence: Afferent input from the retina is sent to the lateral geniculate nucleus via the optic tract.
What are the types of pupillary reflex?
Pupillary reflex refers to one of the reflexes associated with pupillary function. These include the pupillary light reflex and accommodation reflex.
What is the grading system for pupillary defects?
The grading system can be compared with the neutral density filter grading system, and each grade has a corresponding value in log units. Clinical grading of relative afferent pupillary defects Arch Ophthalmol. 1993 Jul;111(7):938-42.doi: 10.1001/archopht.1993.01090070056019. Authors
When to test for a relative afferent pupillary defect?
When the test is performed on someone with unilateral or asymmetrical retinal or optic nerve disease, a RAPD should be present (Figure 3). The following happens: When the light is shone into the eye with the retinal or optic nerve disease, the pupils of both eyes will constrict, but not fully. This is because of a problem with the afferent pathway.
Why do I need to test my pupillary light reflex?
Light-near dissociation with dorsal midbrain and pretectal nuclei damage is due to this pathway’s bypassing of the pretectal nucleus. Testing the near response is necessary only if the pupillary light reflex is abnormal; there is no pathologic situation where the near response will be abnormal with a normal pupillary light reflex.
What is the physiology of normal pupillary constriction?
The physiology behind a “normal” pupillary constriction is a balance between the sympathetic and parasympathetic nervous systems. Parasympathetic innervation leads to pupillary constriction. A circular muscle called the sphincter pupillae accomplishes this task. The fibers of the sphincter pupillae encompass the pupil.