Pediatrics and Strabismus Vol. 1 Flashcards Preview

Complete Review Course > Pediatrics and Strabismus Vol. 1 > Flashcards

Flashcards in Pediatrics and Strabismus Vol. 1 Deck (37):
1

What differentiates a phoria from a tropia?

Presence or absence of fusional control

2

What angle does the inferior oblique muscle form with the visual axis in primary position?

51 degrees

3

What is the only rectus muscle that does not have an oblique muscle running tangential to it?

Medial rectus

4

What angle does the superior rectus muscle make with the visual axis?

23 degrees

5

What is the function of the superior rectus muscle primary, secondary, and tertiary action in primary position?

Primary - elevation Secondary- intorsion Tertiary- adduction

6

What angle does the inferior rectus muscle form with the visual axis?

23 degrees

7

What is the function of the inferior rectus muscle primary, secondary, and tertiary action in primary position?

Primary- depression Secondary - extorsion Tertiary- adduction

8

What is the function of the superior oblique muscle primary, secondary, and tertiary action in primary position?

Primary - intorsion Secondary - depression Tertiary- abduction

9

What angle does the superior oblique muscle form with the visual axis in primary position?

51 degrees

10

What is the function of the inferior oblique muscle primary, secondary, and tertiary action in primary

Primary- extorsion Secondary - elevation Tertiary- abduction

11

Which extraocular muscle has the longest tendon?

Superior oblique (26 mm)

12

Which extraocular muscle has the shortest tendon?

Inferior oblique (1 mm)

13

What is the primary arterial supply to the extraocular muscles?

Muscular branches of the ophthalmic artery

14

What are the two major branches of the muscular branches of the ophthalmic artery?

Medial and lateral muscular branch

15

What four muscles are supplied by the lateral muscular branch of the ophthalmic artery?

1. Lateral rectus 2. Superior rectus 3. Superior oblique 4.Levator palpebrae

16

What three muscles are supplied by the medial muscular branch of the ophthalmic artery?

1. Inferior rectus 2.Medial rectus 3. Inferior oblique

17

What artery partially supplies the lateral rectus muscle?

Lacrimal artery

18

What artery partially supplies the inferior rectus and inferior oblique muscle?

Infraorbital artery

19

Which arteries are carried by each rectus muscle and supply blood to the anterior segment?

Anterior ciliary arteries

20

Which rectus muscle carry the bulk of the anterior ciliary arteries?

Superior and inferior rectus muscle

21

What does the venous drainage system of the extraocular muscles drain into?

Superior and inferior orbital veins

22

What is the posterior attachment of Tenon's capsule?

Optic nerve sheath

23

What is the anterior attachment of Tenon's capsule?

Intermuscular septum (3 mm from the limbus)

24

Where do the extraocular rectus muscles penetrate Tenon's capsule?

10 mm posterior to their insertions

25

What structure separates the extraocular muscles from the orbital fat and structures outside the muscle cone?

Tenon's capsule

26

What structure separates the intraconal fat pads from the extraconal fat pads?

Intramuscular septum

27

What forms Lockwood's ligament?

Fusion of the muscle capsule of the inferior oblique and inferior rectus muscle

28

What does Lockwood's ligament connect to?

Lower eyelid retractors

29

What structure separates the intraconal orbital fat from the sclera?

Tenon's capsule

30

Where does the extraconal orbital fat and anteriorly?

10 mm from the limbus

31

Approximately how far an instrument must be thrust posterior to the rectus muscles insertion to cause damage to their nerves?

26 mm

32

Which cranial nerve lies outside the muscle cone and is NOT affected by a retrobulbar block?

CN IV

33

Which extraocular muscle nerve can also cause pupil abnormalities if damaged?

Nerve to the inferior oblique muscle

34

Which extraocular muscle surgeries may also cause palpebral fissure changes?

Superior and inferior rectus surgery

35

What vascular complication must be considered when performing simultaneous surgery on 3 rectus muscles, especially in older patients?

Anterior segment ischemia

36

What complication may occur if Tenon's capsule is penetrated 10 mm or more posterior to the limbus?

Prolapse of orbital fat

37

Where is the sclera the thinnest?

Posterior to the rectus muscle insertions