Pupils Flashcards
Pupils Reactions Procedure -
1) Room lights on
2) Prescription NOT worn
3) Explain “this test checks your pupil reflexes to light”
4) Ask: “Please look at a letter/spotlight on the distance chart”
What to Measure and Observe?
Are the pupils EQUAL IN SIZE?
Are the pupils ROUND?
Measure the DIAMETER of the pupil
Anisocoria
Defined by a difference of 0.4 mm or more between the sizes of the pupils of the eyes.
Use a letter if Unaided Vision ______
Better than 6/18
Use spot if Unaided Vision ________
Worse than 6/18
Anisocoria is often entirely harmless but ______________
Can be a sign of more serious medical problems like pathology, injury, surgery etc.
Size of a Normal Pupil
LIGHT
2-4mm
Size of a Normal Pupil
DARK
4-8mm
With age, pupils get smaller and the dilator muscles atrophy
Senile Miosis
Pupillary Hippus
The physiological spasmodic, rhythmic, dilating and contracting pupillary movements between the sphincter and dilator muscles in response to light.
Direct & Consensual Response Procedure -
1) Leave room lights off
2) Remind patient: “Please keep looking at the letter/spotlight.”
3) Shine a light in Right Pupil from inferotemporal side at a distance of 5-10cm using a pen torch
Swinging Flashlight Test
Used for the detection of Relative Afferent Pupillary Defects.
Swinging Flashlight Test Procedure -
1) Leave room light off
2) Remind patient: “Please keep looking at the letter/spotlight.”
3) Shine a light in R pupil for 2-3seconds from the inferior side at a distance of 5-10cm
4) Quickly shine light in L pupil for 2-3seconds
5) Alternate several times
What is RAPD?
Relative Afferent Pupillary Defect =
Detected if one eye dilates (rather than constricts) when the light shone on it.
Normal Pupils Acronym
PERRLA
No RAPD
Near Response to Light
Only do this if the light reflex is abnormal
Near Response to Light Procedure -
1) Leave room light off
2) Remind patient: “Please keep looking at the letter/spotlight.”
3) Ask: “Now look at my finger.”
Hold finger about 25cm in front of the patient.
4) Observe extent of pupillary constriction as patient changes fixation from D to N
5) Ask “Now look back at the letter/spotlight”
6) Observe extent of pupillary dilation as patient changes fixation from N to D.
7) Record ‘Light-Near Dissociation’ if light reflex abnormal while near reflex normal.
Near Response to Light Procedure -
1) Leave room light off
2) Remind patient: “Please keep looking at the letter/spotlight.”
3) Ask: “Now look at my finger.”
Hold finger about 25cm in front of the patient.
4) Observe the extent of pupillary constriction as the patient changes fixation from D to N
5) Ask “Now look back at the letter/spotlight”
6) Observe the extent of pupillary dilation as the patient changes fixation from N to D.
7) Record ‘Light-Near Dissociation’ if light reflex abnormal while near reflex normal.
Horners Syndrome
A condition characterised by a contracted pupil, drooping upper eyelid, and local inability to sweat on one side of the face, caused by damage to sympathetic nerves on that side of the neck.
Meiosis
Ptosis
Anhidrosis
Physiological Anisocoria
About 20% of normal people have a slight difference in pupil size of less than 1 mm.
Mechanical Anisocoria
Occasionally previous trauma, eye surgery, or inflammation (uveitis, angle-closure glaucoma) can lead to adhesions between the iris and the lens.
What are the key things to assess with Pupils?
- Anisocoria
- Horners Syndrome
- Adie Tonic Pupil
- Oculomotor Nerve Palsy
Adie Tonic Pupil
A pupil with Parasympathetic denervation that constricts poorly to light but reacts better to accommodation - Near response.
Oculomotor Nerve Palsy
Ischemia, intracranial aneurysm, demyelinating diseases (e.g., multiple sclerosis), head trauma, and brain tumours are the most common causes of oculomotor nerve palsy in adults. In ischemic lesions of the oculomotor nerve, the pupillary function is usually spared whereas in compressive lesions the pupil is involved.
