Ocular Motility Testing 5% Flashcards
When checking stereo vision you must have_________
good vision in both eyes
Maculas projected straight ahead
Overlapping VFs
Monoculary pts can have depth perception but can not have
stereo vision
A high quality of vision that gives you 3D
Stereo vision
How many extraocular eye muscles do we have
6
Name the eye muscles
superior rectus
Inferior rectus
lateral rectus
medial rectus
superior oblique
Inferior oblique
The superior oblique is attached under the
superior rectus in an oblique fasion
Inferior oblique is attached under the
lateral rectus muscle in an oblique fashion
*What is the function of the superior rectus muscle
move eye upward (elevates)
*What is the function of the inferior rectus muscle
Move eye downward(suppresses)
*What function does the superior oblique have
downward and out(tortional rotation)
*What function does the inferior oblique have
elevates the eye up and out (torsional rotation)
*What is the function of the lateral recuts
move eye outward(abduct)
Superior oblique is attached to the ______
Troclea(you can feel it in nasal canthus area.)
What are the 2 types of eye movements?
Sacaad and Pusuit
Fast eye movements moving eye directly from one target to another, looking at stationary objects
Sacaad
Slow eye movements looking at moving objects: slow smooth tracking of a moving target
Pursuit
Law that state that each muscle has an opposing muscle in the same eye that does the opposite thing. When one muscle contracts the antagonist (opposite) muscle in the same eye must relax.
Sherrington’s Law
In Sherrington’s Law the opposing muscle must relax when the opposing muscle is ______
contracting.
The binocular law (law of Yoke Muscles) that states that each position of gaze is accomplished by contraction of one muscle in each eye and the amount of innervation to both eye muscles is determined by whichever eye is fixating.
Herring’s Law
True or false:
During any conjugate eye movement, equal and simultaneous innervation flows to both yoke muscles.
True
what is the function of the medial rectus
moves eye inward(adduct)
*How many cranial nerves are there?
12
Name the 12 cranial nerves
Olfactory Nerve I (1)
Optic Nerve II (2)
Oculomotor nerve III (3)
Troclear Nerve IV (4)
Trigeminal Nerve V (5)
Abducens Nerve VI (6)
Facial Nerve VII (7)
Vestibulocochlear Nerve VIII (8)
Glossopharyngeal Nerve IX (9)
Vagus Nerve X (10)
Accessory Nerve XI (11)
Hypoglossal Nerve XII (12)
*What does SO4 LR6 III Mnemonic stand for?
SO4=superior oblique innervated by CN4
LR6=Lateral Rectus innervated by CN6
III=all other muscles innervated by CN3
Cranial nerve is a nerve that comes directly from ______as opposed to spinal cord
Brain
*What are the cranial nerves that apply to ophthalmology?
Optic nerve CN2(II)
Oculomotor nerve CN3(III)
Trochlear Nerve CN 4(IV)
Abducens nerve CN 6(VI)
Which CN transmits visual information to the brain?
Optic nerve (CN 2)
Which CN innervated the superior oblique, which depresses and rotates the eyes?
Troclear Nerve CN4
Which CN innervates the lateral rectus, which abducts the eye?
Abducens nerve (CN6)
Which CN innervates the levator muscle, superior rectus, medial rectus, inferior rectus, and inferior obliques? Also innervates ms the sphincter pupillary muscle and the ciliary body muscle.
Oculomotor nerve (CN3)
What is the 2nd CN
Optic nerve
What is the 3rd CN
Oculomtor nerve
What is the 4th CN
Trochlear nerve
What is the 6th CN
Abducens nerve
What is CN 1
Olfactory nerve
What is CN 5
Trigeminal
What is CN 7
Facial nerve
What is CN8
Vestibulocochlear nerve
What is CN 9
Glossipharyngeal nerve
What is CN10
Vagus nerve
What is CN 11
Accessory nerve
What is CN12
Hypoglossal nerve
*What is a Cranial nerve palsy?
Means that a nerve can not send an impulse properly.
(Know the difference in CN palsies that effect the eyes)
What causes a cranial nerve palsy?
Disease or trauma
Stroked, brain tumors, diabetes
What determines the deficit of a CN palsy?
which nerve is involved and where on the nerve the problem is.
CN palsy has very different causes depending on the pts_____
Age
What are the causes of CN palsies with over age 40
DM
CVA (strokes)
Basilar artery insufficiency(poor blood flow to back of brain)
GCA(giant cell arteritis)
What are the main causes of CN palsies Under age 40?
Congenital Defects
Cranial Artery Aneurysms
Head Trauma
MS
Secondary to increased intracranial pressure
Double VA with both eyes open
binocular diplopia
What causes binocular diplopia?
misalignment of the eyes
(Strabismus, damage to nerves controlling the EOM, myasthenia gravis, thyroid disease, trauma)
Double vision with one eye covered
Monocular diplopia
What cause monocular diplopia
an imperfection in the eye
(CAT, K irregularities, uncorrected astig, some retinal abnormalities suck as macular puckering)
Ductions are _______movements
monocular (movement of one eye)
When looking at right eye and it moves left that is called
adducting
When looking at right eye and it moves right it is
abducting
When eye looks up it is
supraduction
When eye looks down that is
infraduction
outwart movement
abduction
inward movement
adduction
upward movement
supraduction
downward movement
infraduction
torsional inward movement
incycloduction
tornsional outward movement
excycloduction
*Simultaneous movements of both eyes in the same direction
Versions
dextro means
right
cyclo means
rotation
*Simultaneous movements of both eyes in opposite direction
Vergences
Both eyes move toward one another (looking at near)
converging
When look from near to distance eyes ______
diverge
How many cardinal positions are there
6
What are the six cardinal positions
Up and right(RSR, LIO)
right (RLR, LMR)
down and right(LSO, RIR)
up and left(RIO, LSR)
left (RMR, LLR)
down and left(RSO, LIR)
True or false:
Everyone has a phoria and it’s natural
True
Phorias and tropias are classified by the __________________
Direction of deviation
Esotropia or Esophoria
Eye deviates inward
Exotropia or exophoria
Eye deviates outward
Hypertrophia or hyperphoria
Eye deviates upward
Vertical deviations are classified according to ______
The higher eye
Eye deviates down you would refer to that as a________of the fellow eye even if the fellow eye is the normal eye
Hyper
If there is a motility disturbance with no diplopia the deviation must be_____
Congenital or very poor vision
What are the common types of strabismus?
Exotropia
Esotropia
Accommodative Esotropia
Hypertropia
Nystagmus
Cranial nerve palsies
Both eyes open….tropia or phoria?
Tropia
One eye open….tropia or phoria?
Phoria
It the exotropia is acquired rather than congenital, it is usually because of _____________
Poor VA in one eye
Left eye is deviated outward
Left exotropia
Left eye is deviated inward
Left esotropia
What is the most common for of esotropia affecting 1-2% of population
congenital
When pt only fixates with one eye at a time and one eye always deviates out and pt can and does fixate with either eye
Alternating tropia
*Condition that typically causes a ptotic lid and on the side with the ptotic lid may be a mid dilated pupil typically 5-6 mm dilated. The pt will have an anisocoria and the eye with the ptotic lid will be deviated down and out.
3rd Cranial Nerve Palsy
3rd Cranial Nerve Palsy that typically does not have pupil involvement
DM 3rd CN palsy
Condition(palsy) characterized by hypertropia on primary gaze. This is caused by the superior oblique being palsied so the inferior oblique is acting (pulling up) without the counter inferior oblique working against it to balance by pulling it down.
4th CNP
Palsy characterized by abduction deficit and esotropia. This is caused by the lateral rectus being palsied and the opposing muscle is pulling without be counteracted causing they eye to pull in that direction.
6th CNP
*With cover/uncover test observe the eyes as the pt fixates on a ______, ______target
small, distant
*When doing cover/uncover what eye are you looking at?
The uncovered eye.
*Cover/uncover tests for tropia or phoria?
Tropia
*Explain how to perform a cover/uncover test.
- observe eye as the pt fixates on a small, distant target.
- Cover one eye
- Look at the uncovered eye
- Eye moves=Tropia
- Repeat with other eye
- Look only at the uncovered eye.
In Cover/Uncover test if you cover the left eye and the right eye moves out you have a _______
Right esotropia
When doing cover/uncover we are observing the eye recover from its deviation not observing the deviation itself, therefore it is recorded from ________
where it moves from
ex: cover right eye and left moves inward =left extropia
left eye cover and right eye moves outward=right esotropia
Which test is used to detect a phoria?
Alternate cover test (aka: cross cover test)
Explain how to do a cross cover test.
- Observe eyes as the pt fixates on a small, distant target.
- Alternately cover one eye then the other
- Do not allow the pt to be binocular
- Look at the covered eye as it is being uncovered
- Uncovered eye moves=phoria
With cross cover test do not ever allow pt to be _______
binocular
Which eye are you observing in cross cover test?
The covered eye as it is being uncovered
When performing cross cover test you are observing the eye __________
Recover from its deviation, not the deviation itself (so it is recorded from the point it moves from)
In this test you are testing for a tropia, you do allow the pt to be binocular, and you are looking at the uncovered eye.
Cover/Uncover test
In this test you are testing for a phoria, pt is never to be binocular, and you are looking at the eye as you uncover it.
Alternate cover test (cross cover test)
When talking about tropias and phorias, which one is always there and which one do you have to look for.
Tropia is always there
Phoria you have to look for
If the pt does not have prism in their glasses you should do cover tests with glasses _______
off
If pt has a has prism in their glasses you can have them _______ for cover tests. If they have prism in their glasses and you want to document total deviation have pt _______
ON
take off glasses
Misalignment that is always there, even when both eyes are open and attempting to work together. Large angle deviations are obvious. If small angle, you can detect it with the Cover-Uncover test
Tropia
Misalignment that only occurs some of the time, such as when the synchronization between the eyes is broken by the covering one eye. You can “break fusion” using he Cross-Cover test
Phoria
Near point conversion is a ____test measured in ____
binocular
cm
To measure Near point conversion pt looks at ______target
small
with near point conversion record distance at which pt can no longer maintain ______(one eye will deviate outward)
Fusion
When checking near point convergence, pt must be…….
Alert and cooperative and have normal fusion (cannot be amblyopic)
What is the formula to determine the diopter of the lens if you know the focal length?
D=1/F
(D=Dioptric Power of Lens)
(F=Focal Lenght (in meters)
If focal point is 1/3 of a meter (1/.33) what is the Dioptric power
D=3
(D=1 divided by .33cm=3D)
Think $ and cents (it takes (3) 33cents to reach $1 so the answer is 3D)
Focal points are measured in _____
meters or parts of meters
What is the formula to determine focal length?
F=1/D
F=Focal length in meters
D=Dioptric power of lens
If Dioptric power is 4 then what is the focal length?
25cm
F=1 divided by 4 (1/4)
Think dollars and cents : it takes 4 quarters to equal $1, so it takes (4) 25cm to equal 1
Is measuring accommodative aplitude a monocular or binocular test?
monocular
Push-Up Method is also known as the ….
Proximity Method
Proximity method is measured in _____but express in _____
cm
D
*How do you convert cm to D?
Divide cm into 100 (100/cm=D)
(ex. convert 25cm into dioptors… 100/25=4D)
(D=1/F)
When doing Proximity Method aka “Push-Up Method”, what do you do when a pt is presbyopic?
Add +2.50 over the pts distance Rx and subtract 2.5 from the measurement.
How do you perform Proximity Method (Push-Up Method)?
Have pt look at small print (J3) held at a comfortable arms length, gradually moved closer til print blurs (with effort). This is a salient point, it’s not the first point at which it blurs, you must ask the pt to try to focus. Must stimulate their accommodation.
*How do you determine accommodative amplitude (expressed in D) mathematically?
Convert near point and far point form cm to D then subtract and get the difference between the 2..this will be your accommodative amplitude.
Ex:
Near point is 10cm
Far point is 50cm
10cm=.1 Meters and 50cm =.5 Meters
D=1/.1 answer=D=10 and D=1/.5 answer: D=
(think $ and cents: it take (10) 10 cents to equal 1 dollar so (10)10 cm to equal 1 Meter and (2) 50 cents to equal $1 so (2)50cm to equal 1 meter)
10-2=8D accomodative amplitude
Spherical lens test is used to determine what?
Accommodative Amplitude
Is Spherical Lens Test a monocular or binocular test?
Monocular
What are 3 ways to get accommodative amplitude?
Proximity Method(Push-up Method), Mathematically, and Spherical Lens Test.
How do you perform Spherical lens test?
Have pt put distance Rx on, have them hold reading card at a comfortable distance (40cm), have them fixate on stationary threshold size type (0.5 size), add plus sphere lenses until print is blurred, add minus sphere lenses until print blurs again, the difference in = accommodative amplitude.
Why must you add plus sphere first when checking accommodative amplitude?
Because if you start with minus first you have stimulated their accommodation and you can’t do the test.
Is Fusional convergence amplitude test binocular or monocular?
binocular
Convergence is a ______action, therefore convergence tests are always_______
binocular
binocular
How is fusional convergence measured?
with prisms
What are we artificially stimulating with convergence amplitude tests?
Convergence disparity
What are we assessing with convergence amplitude testing?
the power and stability of the motor fusion and the pts capacity to compensate for phorias.
How do you perform Fusional Convergence Amplitude testing?
Place the prism bar in front of one eye and gradually increase horizontal or vertical prisms while pt fixates on a muscle light. Can do at 36cm and 6M. The point at which the pt reports diplopia is recorded as the break point. This is measured in prism D. What ever D prism is recorded when they reported diplopia is their break point. You then gradually reduce prism until their vision fuses, this is the recovery point recorded in prism D.
Prisms bend light rays towards their _____
base
An object viewed through a prism appears displaced toward the prism _____
apex
Prism corrects the _______ of the eye but does not correct the _______
sensory alignment
motor alignment
Prism simply moves where virtual space is in front of the ____eye
deviated
You point the prism in the direction of the ______
deviation
If pt has exo-deviation you would correct with what?
Base in prism
If pt has eso-deviation you would correct with
Base out prism
If pt has hyper-deviation you correct with
base down prism
If pt has hypo-deviation you correct with
Base up prism
Apex of the prism points in the direction of the _____
deviaiton
The magnitude of prism effect depends on _______
size of angle of the apex of the prism
1 prism diopter=prism which appears to displace an object ___cm of ___M.
1, 1, 1
*At 0.5 M if the object is displaced in 1 cm P=___
2
*What is the formula to calculate magnitude of prism effect?
P=C/D
Prism=displacement of object in cm divided by Distance from prism in meters
When prescribing prism we usually
split it between the 2 eyes
Why do we split the prism between the 2 eyes?
May be more cosmetically pleasing
Pt may feel more balanced
It may be cheaper for pt
How do you split vertical prism?
Split the prism oriented in opposite directions
(ex: if they need 6 prism D BUOD you would put 3 PD BU OD and 3 PD BD OS. Doesn’t matter which eye gets BU or BD for vertical prism
How do you split horizontal prism?
The prism is always split in the same direction.
If they need 6PD BO OD we would give 3PD BO OD and 3PD BO OS.
*The Worth 4 DOT test uses and illumitated diamond patter that detects the presence of ____ or ____
fusion
suppression
Worth 4 DOT test can be performed ___or ____
near or distance
*What is the Worth 4 DOT test used for?
To detect the presence of fusion or suppression in one eye
*In Worth 4 DOT test pt wears________and reports_______
red&green glasses (red over right, green over left)
number and color of lights they see
Worth 4DOT test:
White light green and red or alternation
Normal Fusion
Worth 4 DOT test:
White light color of dominant eye’s lens
One eye definitely dominant
*Worth 4 DOT test:
4 lights-2 green, 1 red, one pink or pale green
Single binocular vision
*Worth 4 DOT test:
5 Lights-3 green, 2 red
Diplopia
*Worth 4 DOT test:
2 red or 3 green
Suppressing (colors seen depends on which eye is suppressing)
With Worth 4 DOT test pt may have different responses for ________
Near and distance
*What does the Maddox Rod test for?
Phoria and tropia
Is Maddox rod a bincocular or monocular test?
Binocular
Should Maddox Rod be performed at near or distance?
both
Near @16” and Distance at 20’
Should Maddox Rod be perform vertically or horizontally?
both
How does the Maddox Rod work?
It converts white point of light into red line perpendicular to the position of the lines on Maddox Rod.
When you orient the Rod of Maddox rod horizontally you are checking for ….
a horizontal deviation
(eso or exo deviation)
When you orient the rod of Maddox Rod vertically you are checking for a….
vertical deviation
(hyper deviation)
Maddox Rod:
When rod is oriented vertically, pt will perceive line of light to be _____(and vice versa)
horizontal
Maddox Rod detects the ability of the eyes to focus on ___
the same object
In Maddox Rod:
With MR over OD holding rod horizontal, pt sees light source to left of vertical line
Right esophoria in relation to the left eye
In Maddox Rod:
MR is held horizontal over OD, pt sees light source to the right of the vertical line.
Right exophoria in relation to the left eye
In Maddox Rod:
MR held over OD horizontally, pt sees light superimposed over the vertical line.
Orthophoria (normal)
In Maddox Rod:
MR held over OD Vertically, pt sees light source superimposed over horizontal line.
Orthophoria (normal)
In Maddox Rod:
MR is over OD Vertically, pt sees light source above horizontal line
Right hyperdeviation
In Maddox Rod:
MR is held over OD vertically, pt see light source below horizontal line.
Left hyper deviation
*What is the Hirschberg Corneal Light Reflex Testing?
A preliminary test to determine the magnitude of the deviation in older children. Not sensitive enough for small deviations.
How do you perform Hirschberg Corneal Light Reflex Testing?
Shine a light at the pt and note where the K light reflex falls in relation to their pupil.
*An approximation further defined by Krimsky Test is 1 mm=
7 degrees of deviation
*Krimsky K light reflex testing:
7 degrees of deviation =
15 prism diopters
Krimsky corneal light reflex test is the same test as_______test only it also uses a prism.
Hirshberg test
How do you perform Krimsky Corneal Light Reflex Testing?
Hold the prism in front of the fixating eye, increase the strength of the prism until the K reflexes are centered in both eyes.
Krimsky:
The Strength of prism required to center K reflection in deviating eye=
amount of deviation present
Krimsky is a _____ measurement of the deviation, Hirschberg is an ____
definitive
approximation
A problem between a neuroconnection between the brain and the eye. We can’t improve the vision with corrective lenses and the pt has a normal eye and a normal brain. Pt has a difference of 2 lines or more between their eyes or best corrected VA of 20/30 or worse.
Amblyopia
What is the treatment goal for amblyopia?
20/30 or 20/25
How do we treat amblyopia?
Occlude or patch the good eye or blur it with atropine
What is the purpose of patching or blurring the good eye when treating amblyopia?
Forces the bad eye to be used and helps the neurologic connection to happen.
When treating amlyopia, the older the child_______
the longer it takes to treat the condition.
It pt is born with ptosis or congenital cataract we call that
stimulus deprivation
Stimulus deprivation has to be treated in the first______. All other cause of amblyopia can be fixable up to age_____
few weeks of life
6 or 7yo
What are some Unilateral causes of Amblyopia?
Strabismus(Suppression)
Significant Uncorrected refractive errors of one ye (Anisometropia)
Stimulus deprivation (CAT, Ptosis, K opacities)
What are some Bilateral causes of Amblyopia?
Bilateral significant uncorrected refractive errors
Bilateral stimulus deprivation
Treatment for amblyopia depends on
the cause
If the eye has strabismus causing amblyopia you treat it by
correcting the muscle problem with sx then you can treat amblyopia once the eye is straight.
Therapy aimed at the higher centers of the brain
Convergence Training (aka Vision Therapy or Orthoptics)
In Convergence training the child must be…
alert and cooperative and cannot be amblyopic
Convergence training trains the ______ not the eye.
brain
What are the 3 types of Vergence training?
Sustained
Pursuit
Saccad
Vergence training: reading through a prism
Sustained
Vergence training: track a moving target in depth
Pursuit
Vergence training: quick changes in fixation distances(from near to distance)`
Saccad
