What could it mean if the pupillary reflexes are absent?
Pupillary light reflex is used to assess the brain stem function. Abnormal pupillary light reflex can be found in optic nerve injury, oculomotor nerve damage, brain stem lesions, such as tumors, and medications like barbiturates.
Which cranial nerve can be tested by the pupillary light reflex?
LIGHT REFLEX TESTING Pupillary light reflex is an example of a brainstem reflex. When light is directed toward eye, CN II (Optic – sensory nerve) will carry the input to CN III. Light directed toward either eye will immediately stimulate CN III in both eyes.
What does no pupil response mean?
Abnormalities such as an irregular pupil size or shape, or a delayed or nonreactive pupil can be indicative of significant head trauma. A score of 2 means both pupils are non-reactive to light; a score of 1 means one pupil is non-reactive; and a score of 0 means neither pupil is non-reactive. Improving GCS Score.
What is the purpose of the pupillary light reflex?
The pupillary light reflex allows the eye to adjust the amount of light reaching the retina and protects the photoreceptors from bright lights. The iris contains two sets of smooth muscles that control the size of the pupil (Figure 7.2).
How do you test your pupillary light reflex?
Swing a light back and forth in front of the two pupils and compare the reaction to stimulation in both eyes. When light reaches a pupil there should be a normal direct and consensual response.
What is direct and indirect light reflex?
Right direct pupillary reflex is the right pupil’s response to light entering the right eye, the ipsilateral eye. Right consensual pupillary reflex is the right pupil’s indirect response to light entering the left eye, the contralateral eye.
How do you test pupillary response?
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 does pupil response indicate?
Pupillary response is a physiological response that varies the size of the pupil, via the optic and oculomotor cranial nerve. A constriction response (miosis), is the narrowing of the pupil, which may be caused by scleral buckles or drugs such as opiates/opioids or anti-hypertension medications.
Can you recover from non-reactive pupils?
No patient survived with bilateral non-reactive pupils immediately after treatment. No patient survived better than a vegetative state with only one pupil reactive to light after treatment. Much better results were found when both pupils showed reactivity to light immediately after therapy.
What kind of reflex is pupillary light reflex?
Pupillary reflexes involve the autonomic (Edinger-Westphal) component of the oculomotor nucleus. In the light reflex, the pupils constrict when light is shone on the retina. If one eye only is stimulated, both pupils constrict, the so-called consensual reflex.
What is pupillary dilation?
Dilated pupils (mydriasis) are when the black center of your eyes are larger than normal. The condition may be caused by dilating eye drops from an eye exam, the side effects from a drug/medication or traumatic injury.
What is abnormal pupillary light reflex?
Abnormal pupillary light reflex can be found in optic nerve injury, oculomotor nerve damage, brain stem lesions, such as tumors, and medications like barbiturates. Equipment A pocket penlight is inadequate
What are direct and consensual pupillary light reflexes?
Direct and consensual pupillary light reflexes test for appropriate neurological pathway connections and functioning of both cranial nerve II and III. Light entering the eye is processed through the pupillary light reflex, and signals directed to the iris sphincter muscle to adjust the amount of light that reaches the retina.
How are the pupillary reflexes tested clinically?
The pupillary reflexes are tested clinically using a pen torch ( Fig. 3.28 ). Illumination of one eye causes reflexive constriction of both pupils: via the direct and indirect pupillary light reflexes. This is mediated by projections from the retina to the pretectal nucleus of the midbrain,…
Is the relative afferent pupillary defect in the unreactive pupil?
Direct and consensual responses should be compared in the reactive pupil. If the reactive pupil constricts more with the direct response than with the consensual response, then the relative afferent pupillary defect is in the unreactive pupil.