PC - Routine Screening 1 - Week 4

Question 1

On which population must stereopsis and colour vision be performed?

Answer 1

Children

Question 2

What could a sudden onset of strabismus in adults be an indicator of?

Answer 2

Stroke or tumour.

Question 3

Define and describe how NPC is carried out.

Answer 3

MEasure of how well you can bring your eyes inward.
Begin habitual reading, and slowly bring closer until sustained double vision is perceived.
Take the distance in cm, then reverse until recovery. Take in cm.
Write as B/R - break/recovery

Question 4

Define and describe how NPA is carried out.

Answer 4

A measure of the focusing power of the eye.
Start habitual reading and slowly move inward until a sustained blur perceived.
Take in m, and convert to D.

Question 5

What is the principal action of the medial rectus muscle?

Answer 5

Adduction

Question 6

What is the principal action of the lateral rectus muscle?

Answer 6

Abduction

Question 7

What is the principal and secondary actions of the superior rectus muscle?

Answer 7

Principal
-Elevation
Secondary
-Adduction
-Intorsion

Question 8

What is the principal and secondary actions of the inferior rectus muscle?

Answer 8

Principal
-Depression
Secondary
-Adduction
-Extorsion

Question 9

What is the principal and secondary actions of the superior oblique muscle?

Answer 9

Principal
-Intorsion
-Depression
Secondary
-Abduction

Question 10

What is the principal and secondary actions of the inferior oblique muscle?

Answer 10

Principal
-Extorsion
-Elevation
Secondary
-Abduction

Question 11

What 4 muscles are innervated by cranial nerve III?

Answer 11

Medial rectus
Superior rectus
Inferior oblique
Inferior rectus

Question 12

Which muscle is innervated by cranial nerve IV?

Answer 12

Superior oblique

Question 13

Which muscle is innervated by cranial nerve VI?

Answer 13

Lateral rectus

Question 14

Describe the test for ocular motility, including what to look out for.

Answer 14

Have patient focus on the largest letter on the PD ruler, and test at 40cm, and evaluate 9 positions of gaze.
Have them report any diplopia or pain.
Check for over/underaction, and jerky movements.
Check for head tilting, chin posture, and double vision.

Question 15

Consider an eye with RAPD. How can this be seen using a neurological pupil test?

Answer 15

Shining a light into an unaffected eye will result in constriction and consensual restriction in the affected eye.
Shining a light into the affected eye directly will result in no constriction, and no consensual constriction in the unaffected eye.

Question 16

Colour vision deficiency is more common in which gender?

Answer 16

Male.

Question 17

What is the most common colour deficiency?

Answer 17

R-G

Question 18

Can colour deficiency be acquired?

Answer 18

Yes.

Question 19

Define the following:
Protanomal
Deutanomal
Tritanomal

Answer 19

Protanomal - missing red cone pigment
Deutanomal - missing green cone pigment
Tritanomal - missing blue cone pigment

Question 20

Describe the test for colour vision. What constitutes a fail?

Answer 20

Conducted at 75cm with the lights on. More than 2 errors is a fail.

Question 21

What happens if a patient presents with one droopy eyelid, and looking down and left?

Answer 21

Highly suggestive of posterior cortical atrophy, and is likely to result in death if untreated immediately.

Question 22

What happens if ptosis occurs with anisocoria?

Answer 22

Palsy of the third cranial nerve. Can be fatal.

Question 23

Define ptosis.

Answer 23

Droopy eyelid

Question 24

Describe the neurological pupil test.

Answer 24

Shine a light into each pupil, and check the unilluminated one for consistent and smooth consensual constriction.

Question 25

Describe the steropsis test, and its working distance.

Answer 25

Normal room light, at 40cm.

Patient must wear 3D glasses and have habitual correction.

Question 26

What is the normal focusing power of an eye?

Answer 26

15 - age/4

Question 27

Define the palpebral fissure aperture, the normal and abnormal measurements.

Answer 27

Distance between the upper and lower eyelids.
Normal - 9-10mm
Abnormal - <9mm

Question 28

Define the marginal reflex distances, the normal and abnormal measurements.

Answer 28

Distance between the superior and inferior lids and the corneal reflex.
Normal - 4-5mm
Abnormal
-MRD1 - <4mm
-1.5mm difference between MRD1 and 2

Question 29

Define the levator function, the normal and abnormal measurements.

Answer 29

Distance between excursion of upper lid margin from full down gaze to full upgaze without brow movement.
Normal - >10mm
Abnormal - <4mm

Question 30

Define the lid crease, the normal and abnormal measurements. What can an abnormal measurement indicate?

Answer 30

Distance from upper lid margin to lid crease.
Normal - 10-11 women, 8-9 men
If the lid crease is higher than normal, or a deeper lid sulcus, it is a sign of aponeurotic disinsertion.