Ocular Motility Flashcards
How are cyclotorsions named
By the top movement in relation to the nose
The angle of SO
54
The angle of IO
51
The angle of SR and iR
23
Spiral of Tillaux
The insertion of the recti muscles.
Hering’s Law
Yoked muscles. Eyes in separate eyes must receive equal innervation
Sherrington’s law
Antagonist muscles of the same eye must relax together like biceps and tricepts
Microsaccades
Intentional conjugate eye movements that move the fovea back and forth on an object of interest after microdifts and micro tremors cause drifting
Microtremors
Unintenial disconjuctae eye movements. Tastes of the three eye movements.
Microdrifts
Disconjugate, unintentional eye movements that are larger and slower than micro tremors.
VOR
Stabilizes images on the retain during brief head movement by producing eye movements in the opposite direction. Stimulated by endolymph in the semicircular canals. Will fade after 30 seconds of duration and OKR will take over with constant motion.
Oculocephalic testing (doll’s head)
Moving the head and watching conjugate eye movements in the opposite direction
Caloric test
Put cold or warm water in a patients ear. Named for the fast phase COWS.
Nystagmus
An involuntary back and forth movement in one or both eyes.
Jerk nystagmus
slow and fast phase. The slow phase is a drift and the fast phase is a correction.
Pendular nystagmus
even back and forth movement of the eyes
Congenital (infantile) nystagmus
Present at birth or before age 6. Affects Males more.
Latent nystagmus
congenital, conjugate jerk nystagmus that increase in velocity and amplitude when one eye is occluded. Associated with essential infantile esotropia and amblyopia.
Spasm nutans
Nystagmus that develops 4-12 months after birth and resolves in 2-8 years. Disconjugate low amplitude pendular nystagmus with head nodding.
Convergence-retraction syndrome
an intermittent jerk nystagmus with a fast phase that causes convergence or retraction of the eyes.
]See-saw nystagmus
elevation and intorsion of one eye with depression and extortion of the fellow eye.
OKN
Maintains a stable image of a moving object when the head is still.
OKR
Takes over for the VOR.
Which direct of OKN is absent until 3-4 months of age
N to T.
Saccades
very rapid yoked eye movements that move the fovea to the abject of interest. Once it has started int cannot change.
What controls saccades
FEF in the frontal lobe contralaterally.
What is ocular flutter and opsoclonus associated with
cerebellar diseases like MG, parkinson, and alzheimers.
Square wave jerk
Rare saccades that inteerfer with fixation
Ocular flutter
multiple spontaneous saccades
opsoclonus
Advanced form where the saccades are not controlled.
Pursuits latency and velocity
125 sec and 50 degrees per second
pursuits latency and velocity
200 sec and 1,000 degrees per second.
What controls pursuits
the ipsilateral parietal lobe
vergence latency and velocity
160 sec and 10 degrees/sec.
Tonic vergence
Eyes position at rest at distance without a stimulus to converge or accommodate. Measured as the best correct distance phobia.
Proximal vergence
awareness that something is near
Fusional vergence
initiated by retinal image disparity
Accommodative vergence
initiated by blur
comitant deviation
is it the same in all positions of gaze. Due to decompensated phobia.
Primary deviation
The deviation of the paretic eye when the normal eye is fixating
Secondary deviaiton
The devotion of the normal eye when the paretic eye is fixating. Always greater!
Red lens testing
Put red lens in front of one eye with a penlight and see where the red light is in relation to the penlight in all different positions of gaze.
Hess Lancaster test
Red lens over the normal fixating eye. The examiner has a red flashlight (viewed by the normal eye) and the patient is given a green flashlight. Then they must match with the red and green flashlight.
Forced ductions
Positive indicates a restriction. Negative indicates a presis.
Duane’s retraction syndrome
CN III controls the MR and LR. Most commonly L eye and females. Type I: Limited ABduction. Type II: limited ADDuction Type III: limited ABDuction and ADDuction. All three types have globe tretration on ADDuctioin.
Brown’s syndrome
mr. brown can go down but he can’t go back up. Small hypotropia in primary gaze.
