2ND LECTURE Flashcards
(24 cards)
What are the aims of clinical placement 1c?
To introduce the student to clinical eye movement testing techniques and to develop an understanding of the principles of management of concomitant strabismus.
What will an undergraduate orthoptist be able to do after clinical placement 1c?
Assess ocular movements, discuss and select appropriate management for patients with concomitant primary and consecutive deviations, and appreciate the role of refractive error in the management of strabismus.
What are the three axes of the Axis of Fick?
- Vertical axis (Z)
- Horizontal axis in the coronal plane (X)
- Horizontal axis in the sagittal plane (Y)
What does Listing’s Law state?
All eye orientations can be achieved starting from a primary eye position, with different gazes achieved by moving around the axis within Listing’s plane.
What is Sherrington’s Law of reciprocal innervation?
Whenever a muscle receives a neural impulse to contract, the antagonist muscle of the same eye receives an equivalent inhibitory impulse.
What is Hering’s Law of equal innervation?
When an impulse goes to a muscle causing it to contract, a simultaneous and equal impulse is sent to the contralateral synergist.
What is Donder’s Law?
For any gaze direction, the eye’s spatial orientation is unique and independent of previous eye orientations/gaze directions.
Define agonist and antagonist muscles in the context of eye movement.
- Agonist: Primary muscle that moves the eye in a particular direction
- Antagonist: Muscle that moves the eye in the opposite direction
What are synergist muscles?
Muscles of the same eye that move the eye in the same direction.
What are yoke muscles?
Pairs of muscles, one in each eye, that produce conjugate eye movements.
Why is it important to test EOMs?
- To establish the extent of movement
- To show the function of different movement systems and their nerve supply
- To isolate the primary underacting muscle
- To assess positions of gaze where motility may be restricted
- To aid diagnosis and management of patients
List the positions to test EOMs.
- Dextroelevation
- Dextroversion
- Dextrodepression
- Depression
- Laevodepression
- Laevoversion
- Laevoelevation
- Elevation
- Primary position
What method is used for testing EOMs?
Test without glasses using a pen torch, observe the patient, and perform cover test in primary position.
What are the observations made during EOM testing?
- Examine versions
- Observe overaction and underaction
- Perform cover test to verify
- Observe up/down shoots/drifts
- Examine ductions
How are defects recorded in EOM testing?
- A description in words
- Diagrammatically
- Indicate underaction or restriction, overaction, and grade of abnormality
What does a grade of -1 indicate in EOM testing?
75% movement.
What does a grade of -4 indicate in EOM testing?
No movement.
What is the significance of a V pattern in EOM testing?
Looking for significant change in horizontal deviation between up and down gaze.
What is the importance of observational skills in EOM testing?
To recognize and interpret what is seen during testing and to accurately record findings.
What is the recommended distance for testing EOMs?
50 cm for optimal comfort and visibility.
What is the role of the observer during EOM testing?
To ensure that corneal reflections are visible and to occlude the eye properly.
What should be done if a patient is fidgety during EOM testing?
Manage the patient by encouraging fixation and possibly having a parent assist.
What is the main focus when recording EOM defects?
To standardize by dividing the movement into quarters and using subjective recording to refine judgment.
What is the significance of knowing the muscle actions during testing?
To understand which muscles are being tested and what movements they are responsible for.
