VF - Eye Movement Testing - Week 6 Flashcards
What is the double-H test useful for assessing, and what does it allow you to see?
Allows you to see if the eyes can move to the locations expected.
It can be used to assess binocularity.
When assessing the alignment of a patients eye during fixation, is it useful to use the corneal reflex of a pen torch to judge aligment?
It can be, but only detects misalignments >7 degrees
How can smooth pursuit be assessed, and how does a failure to pursue present?
Move a fixation target slowly, and observe the eye. If they cannot pursue, then their eyes will jerk to maintain fixation.
How can the vestibulo-ocular reflex system be assessed?
Head thrusts, the direction of which correspond to a particular semicircular canal.
Define VOR failure, and describe its symptoms. Name 3 things that may cause it, and the condition that is associated with it.
Complete loss of the VOR system.
Possible causes are drug toxicity, lesions of both CNVIII nerves, and conditions that affect the vestibular endorgans.
Causes severe oscillopsia whenever the head is moved, resulting in very poor visual acuity.
How will someone present if they have very slow saccades, and how can this be tested?
Name a possible cause of this.
Head thrusts can be used to assess it, as well as asking them to fixate on random targets.
Results in very slow saccades that almost looks like pursuit.
Can be caused by ischaemic damage to the pons.
Define hypermetria. Describe the severe form as well.
When saccades overshoot, and the eye needs to backtrack to fixate on the target.
Severe forms occur when the corrections also overshoot, as do their corrections, and so forth.
Name the 2 muscles for the left and right eyes needed to look top right.
Right - superior rectus
Left - inferior oblique
Name the 2 muscles needed to look up.
Superior rectus and inferior oblique
Name the 2 muscles for the left and right eyes needed to look top left.
Right - inferior oblique
Left - superior rectus
Name the 2 muscles for the left and right eyes needed to look right.
Right - lateral rectus
Left - medial rectus
Name the 2 muscles for the left and right eyes needed to look left.
Right - medial rectus
Left - lateral rectus
Name the 2 muscles for the left and right eyes needed to look bottom right.
Right - inferior rectus
Left - superior oblique
Name the 2 muscles needed to look down.
Inferior rectus and superior oblique
Name the 2 muscles for the left and right eyes needed to look bottom left.
Right - superior oblique
Left - inferior rectus
