Ocular motility/Binocular Vision Flashcards
What do the X, Y, and Z signify in Listings plane?
X - horizontal axis
Y - (is not upward, it is coming out of the plane of the paper!)
Z - vertical meridian
Rotation about the X axis correlates which what kind of movement?
Elevation and Depression
Rotation about the Y axis correlates which what kind of movement?
Torsion movement
Note about cyclo ductions/rotations: they are referenced from the top of the eye. So incyclorotations is the top of the eye rotating IN but remember that this means that the bottom is rotating out.
Rotation about the Z axis correlates which what kind of movement?
Abduction and ADDuction
T or F: ductions are binocular
False, they are monocular movements.
What is a version? (conjugate movements)
Eyes moving in the same direction, binocular movements. (i.e extroversion, levoversion)
What are vergences?
Eyes going in opposite directions, binocular movements
(convergence and divergence)
*vergences have the slowest velocity.
LATERAL RECTUS
- What is the primary action
- Where does it insert
- Abduction
- Lateral aspect of the eye
MEDIAL RECTUS
- What is the primary action
- Where does it insert
- ADDuction
- Anterior to the equator
SUPERIOR RECTUS
- What is the primary action
- Where does it insert
- What degree do we have to move it to isolate its action
- Elevation, Incyclorotation, Adduction
- Anterior to equator
- 23 degrees AbDuction
*For SR, IR, SO, IO, the direction of mvmt used to isolate the muscle is OPPOSITE the direction of horizontal mvmt.
*SR ADDucts, therefore we ABduct it to isolate.
NFERIOR RECTUS
- What is the primary action
- Where does it insert
- What degree do we have to move it to isolate its action
- Depression, Excyclorotation, Adduction
- Anterior to equator
- 23 degrees ABduction
*IR ADDucts, so we ABduct to isolate it
SUPERIOR OBLIQUE
- What is the primary action
- Where does it insert
- What degree do we have to move it to isolate its action
- Incyclorotation, Depression, Abduct
- Posterior to equator
- 51 degrees ADDuction
*SO Abducts, so we ADDuct it to isolate. (O’s to the nose)
INFERIOR OBLIQUE
- What is the primary action
- Where does it insert
- What degree do we have to move it to isolate its action
- Excyclorotation, Elevation, Abduction
- Posterior to equator
- 51 degrees ADDuction
*IO Abducts, so we ADDuct it to isolate. (O’s to the nose)
Spiral of Tillaux
Which muscle has the closest attachment site to the front of the eye?`
MILS
Medial rectus (5.5)-> Inferior rectus -> Lateral Rectus -> Superior Rectus (7.77)
What is Donder’s Law?
For any position of gaze, the eye has a unique orientation in 3D space. The path taken doesn’t influence orientation.
What is Listing’s law?
The eye must rotate around axes to achieve a position of gaze.