Optoprep accom, vergence

Question 1

Sjorgen Disease

Answer 1

Dry eye , Dry mouth , arthritis

Question 2

what is Troxler’s effect

Answer 2

When one fixates at point after 20 seconds the peripheral will fade away

Question 3

What is Version ? what it is purpose ?

Answer 3

BINOcular eye mov. both eye in the same direction . (conjugate)to enlarge the field of view

Question 4

What is vergences ?

Answer 4

both eye to obtain binocular fixation and fusion , eye moves in OPPOSITE direction ? ( disconjugate)

Question 5

what is the function of all superior? what is the function of all Obliques ?

Answer 5

INTORT

AB duct

Question 6

what is the primary function of Obliques ?

Answer 6

INtort and Extort

Question 7

Superior Rectus ?

Answer 7

innervate by CN3 , ( elevation , intort, ADDuct)

Insert on the top of the anterior to the equator and 23 DEGREE temporal to the line of sight

Question 8

inferior rectus ?

Answer 8

innervate by CN3 , insert on the bottom of the anterior to the equator and 23 Degree temporal to the line of sight ( depression, Extrot , ADDuct .

Question 9

Superior Oblique ?

Answer 9

SO4–> CN4 Angle 54 DEGREE ( intort , depression, ABduct )

Question 10

Inferior Oblique?

Answer 10

CN3 , Angle 51 DEGREE ( Extrot , elevation, ABDuct)

Question 11

what is the spiral of Tillaux ?

Answer 11

Describe the line of insertion of recti muscle ( MILS ) Medial Rectus ( closest to limbus)> Inferior Rectus >Lateral>sR

Question 12

Hering’s Law ?

Answer 12

2 EYES , ( Yoked Muscles )two eyes must receive equal innervation . one from each EYE
(LR , MR), (SR, IO), (SO, IR )

Question 13

Sherrington’s Law ?

Answer 13

SAME EYE , one muscle excited and another relax , ( SR,IR),( IO,SO), (LR,MR)

Question 14

Fixation sys?
VOR vestibular sys ?
OKN Optokinetic ?

Answer 14

Fixation–> hold image while head is motionless
VOR–>hold image while short motion of head
OKN–>hold image while prolong head mov.

Question 15

what movement is the fastest ? slowest?

lonngest and shortest latency

Answer 15

SAccades is the fastest , Slowest is the vergence

shortest latency VOR , longest latency Saccades

Question 16

different between OScillopsia Vs Vertigo ?

Answer 16

sensation of objects moving up and down

Vertigo-> sensation of body movement

Question 17

Caloric Test ?

Answer 17

head to one side and water in the inner ear.
Normal –> warm water R ear
–>slow conjugate move to L and
–> fast Movement back to the right ( Nystagmu)
COWS = COLD opposite (Nystagmus
Warm–> Same direction (Nystagmus

Question 18

what you use for Nystagmus ?

Answer 18

BO or (-) lens because converg. decrease Nystagmus

Question 19

what conditions could lead to Nystagmus ?

Answer 19

Aniridia , Albinism, achromatopsia,

Question 20

Pathological Nystagmus Vs physiological ?

Answer 20

Pathological –> associate with ocular motor abnormality ,

Question 21

Different from Optokinetic reflex Vs Optokinetic nystagmus ?

Answer 21

Optokinetic reflex –>hold image on fovea while prolong head Movement (>30 sec)
Optokinetic nystagmus–> Maintain the image of MOVING object on the fovea when the head is still

Question 22

When the OKN developed ?

Answer 22

3-4 months after birth , and cortical region is responsible for it

Question 23

Saccades ?

Answer 23

fastest velocity and longest latency, voluntary but sometimes is involuntary

Question 24

what is the most common saccadic error?

Answer 24

undershooting

Question 25

what is in responsible of Saccades ? (IMPortant)

Answer 25

COntralateral frontal eye field

and ocuuipitoparietal junction

Question 26

what happen is damage in the right frontal eye field ?

Answer 26

impaired saccades toward the left
eye turning to the right

( saccade to Opposite ) side of lesion
eye turn to the SAME side of lesion

Question 27

Damage in superior colliculus?

Answer 27

change in velocity and accuracy od saccades

Question 28

saccades suppression

Answer 28

to prevent blurry image duringsaccade vison is suppresed by cortex

Question 29

Pursuit ?

Saccades?

Answer 29

smooth , slow tracing movement that allow fixation of the fovea on a moving object.
Saccades–> rapid yoked movement move the fovea to an object of interest in the visual field

Question 30

what is the threshold that eye has pursuit ? right before saccades kicks in ?

Answer 30

> 50 degree / seconds –>saccades

Question 31

Pursuit controlled by ?

Answer 31

Parietal lobe to the IPSilateral side

Question 32

Tonic vergence ? Proximal ? Fusinal ?

Answer 32

Tonic vergence–>eye position at rest at distance without stimulus to conv or accom

Proximal conv–> person aware of near target
fusional –> initiated by retinal image disparity and helps the eye compensate for a phoria to obtain bifoveal fixation and binocular vision
( Motor fusion )

Question 33

decompensating phoria ?

Answer 33

large phoria pt used to compensate for it but now it is hardand result in tropia and symptoms of diplopia

Question 34

NON comitant Vs Comitant ?

Answer 34

NOn comitant –> caused by EOM ( misalignment not the same for all gazes )
Comitant –> decompensating phoria

Question 35

SO problem PT will

Answer 35

hyper deviation increase ADduct and depression of affected eye

Question 36

Head TIlt ?

Answer 36

SO–> head tilt AWAY from the lesion side

IO –> head tilt TOWARDS to the lesion side

Question 37

Forced Duction test for Comitancy ?

Answer 37

Positive –> muscle restriction –>eye DOES NOT MOve

Negative–> EYe moves ( Muscle Palsy)

Question 38

Duane’s syndrom

Answer 38

congenital left eye in F,
Type I –> Limites ABduct ( CN6 palsy) most common)
Type II–> Limit AD duct ( leastcommon )
Type III–> Limit AB duct + ADduct

Question 39

Brown’s syndrome ?

Answer 39

Involved SO muscle and tendon abnormality of
trochlea ,
Mr Brown gets DOWN ( HYPOtropia ) in primary gaze and limited elevation during ADduct

Question 40

Parks 3 step

Answer 40

which eye highest hyper deviation ?
is the hyper worse when he looks R or L ?
hyper worse when person tilt her head L or R?

Question 41

R eye
right side
right head tilt ?

Answer 41

1- right eye ( circle the bottom right )
2- right side ( circle my left side)
3- head tilt to R ( circle diagnale to my left )
answer is LIO

Question 42

which eye is only intential and conjugate

Answer 42

microsaccades

Question 43

A +3.00 D hyperope is corrected with a +1.50 D contact lens bilaterally. If he views a near object located at 22.0 cm, what degree of accommodation is required to achieve a clear retinal image (rounded to the nearest 0.25 D)?
+6.00 D

+7.50 D

+1.50 D

+4.50 D

Answer 43

+6.00 D
target require 1/0.22=4.5D
and Pt hyper 3D need 3D to accomed but he is corrected by 1.5
now he has 1.5 hypweropia ( need to accom)
1.5 +4.5 = 6 D

Question 44

While performing the alternating cover test, with the left eye covered, the right eye behind the occluder assumes an exo position. If the right eye were to maintain an exo position when the occluder is removed where would the target’s image fall on the retina in relation to the fovea?

The target’s image would be superior to the fovea

The target’s image would be nasal to the fovea

The target’s image would be inferior to the fovea

The target’s image would be temporal to the fovea

Answer 44

The target’s image would be temporal to the fovea

An exo position places the fovea of the right eye nasal to the image projected from the object of regard. This is due to the outward rotation of the eye which rotates the fovea nasally relative to the object. This places the target’s image temporal to the fovea.

Question 45

A patient is seen at your office reporting horizontal diplopia that is worse towards the end of the day. Unilateral cover testing reveals no movement of either eye. Which of the following can correctly be concluded from the above findings?

The patient does not likely possess a heterotropia or a heterophoria

Further testing is required prior to reaching a conclusion regarding the presence of an ocular deviation

The patient does not likely possess a heterophoria

The patient does not likely possess a heterotropia

Answer 45

The patient does not likely possess a heterotropia

he unilateral cover test (UCT) is useful in diagnosing a heterotropia. If a person does not suffer from a heterotropia, then no movement would be observed on the UCT. A heterophoria would present only on the alternating cover test (ACT).

Question 46

Convergence of the eyes occurs with which of the following?

Extortion of one eye and intorsion of the other

Intortion of both eyes

Adduction of one eye and abduction of the other

Abduction of both eyes

Adduction of both eyes

Answer 46

Adduction of both eyes

In vergence movements, the eyes move in opposite directions. In convergence, both eyes adduct (move medially). In divergence, both eyes abduct (move laterally). Intortion of both eyes is known as incyclovergence. If the left eye abducts and the right eye adducts, both eyes are moving to the patient’s left; this is called levoversion. If the right eye abducts and the left eye adducts, both eyes are moving right and this is called dextroversion.

Question 47

Which of the four involuntary vergence stimuli is driven by neural innervation?

Tonic

Fusional

Accommodative

Proximal

Answer 47

Tonic
Tonic vergence is caused by baseline innervation. This type of vergence is generally maintained when all other vergence stimuli are absent. Proximal stimuli are driven by near objects. The response increases as the distance from the object decreases. Accommodative response results from target defocus. Fusional involuntary vergence is provoked by retinal disparity.

Question 48

You are able to accurately screen for a heterophoria by performing a cover test on your 4 year-old patient. To properly complete this examination, which of the following tests does NOT need to be performed?

Color vision testing

Stereoacuity

Hirschberg testing

Determining the near point of convergence

Monocular estimate method (MEM)

Answer 48

Hirschberg testing
Hirschberg testing and cover testing are both utilized to denote the presence of an ocular deviation; therefore, Hirschberg testing does not need to be performed on this patient.

Question 49

22 year-old male presents with a history of a right orbital medial wall fracture and restriction in right gaze on extraocular muscle testing. Which of the following additional tests is MOST useful in determining whether the limitation is secondary to muscle entrapment or muscle paralysis?

Electrooculogram

Forced duction testing

X-ray imaging

Exophthalmometry

Cover test

Visual evoked potential

Answer 49

Forced duction testing
Forced duction testing is an in-office procedure that is used in differentiating between muscle weakness and restrictive causes of limitations in extraocular muscle movements. This test is typically performed when a patient is anesthetized using topical eye drops. The patient is then instructed to look as far as possible in the direction of the muscle that is suspected of underacting such that maximum innervation is recruited to that muscle. The examiner will then use forceps in order to grasp the conjunctiva as close to the area of the limbus as possible, opposite the side of gaze restriction. If the forceps can then rotate the globe further than where the patient can move it on his own, some degree of muscle paresis is likely. However, if the globe cannot be rotated farther, restriction or entrapment of the muscle is probable. For example, if the patient has a deficit in superior gaze, the insertion of the inferior rectus muscle should be topically anesthetized. The patient’s gaze should then be directed upwards and the inferior rectus muscle should be grasped with forceps. Further superior rotation of the eye should then be attempted. Resistance is considered a positive forced duction test, while effortless rotation is deemed a negative forced duction test.

Question 50

When determining the near point of convergence, which of the following sentences is TRUE?

As the object is moved closer, the accommodative system maintains the target clarity while the convergence system preserves fusion of the object

If diplopia is not reported by the patient, the test should be repeated until the patient reports blurring of the target

As the target is moved closer, diplopia is typically reported prior to blurring of the target

The maximal point of divergence is recorded in centimeters as the ‘break point’

Answer 50

As the object is moved closer, the accommodative system maintains the target clarity while the convergence system preserves fusion of the object

The near point of convergence (NPC) is the point in which the patient’s eyes are maximally converged. The NPC is determined by presenting the patient with an appropriate accommodative target at near and with the patient’s near correction in place, the patient is asked to keep the target clear and single. The target is then brought closer to the patient until either the patient reports that the image of the object appears double or the clinician notes that one of the patient’s eyes turns out. This point is measured and recorded from the spectacle plane in centimeters. While performing the NPC, the convergence system maintains fusion of the target and accommodation sustains clarity. Some patients may report blurring of the target (near point of accommodation) prior to experiencing diplopia, but rarely do patients report blurring of the target after experiencing diplopia. The majority of clinicians record ‘TTN’ or ‘to the nose’ for patients who do not report diplopia or do not exhibit a break in fusion.

Question 51

Nerve fibers from the abducens nucleus innervate which of the following extraocular muscles?

Ipsilateral superior oblique

Contralateral superior oblique

Ipsilateral medial rectus

Ipsilateral lateral rectus

Contralateral lateral rectus

Contralateral medial rectus

Answer 51

CN6= Ipsilateral lateral rectus
CN4=The trochlear nucleus innervates the contralateral superior oblique muscle.

The nucleus of the abducens nerve (cranial nerve VI) is located in the dorsal lower portion of the pons. Motor neuron axons from the abducens nerve course from this location to the ipsilateral lateral rectus muscle via the cavernous sinus and superior orbital fissure. Additionally, interneurons also traverse from the abducens nucleus to the opposite medial longitudinal fasciculus (MLF) and terminate at the oculomotor nucleus, thus coordinating horizontal gaze movements of both eyes.
The oculomotor nucleus innervates the ipsilateral medial rectus, inferior rectus, and inferior oblique, as well as the contralateral superior rectus.

Question 52

The vertical recti muscles are inserted in front of the equator, creating what angle with the visual axis?

23 degrees

67 degrees

19 degrees

51 degrees

39 degrees

Answer 52

23 degrees

The medial and lateral walls of the orbit are positioned at an angle of 45 degrees from each other. The orbital axis then forms an angle of 22.5 degrees with the medial and lateral walls (for the sake of simplicity, this angle is usually regarded as 23 degrees). Therefore, in primary gaze, the visual axis also forms an angle of 23 degrees with the orbital axis. The actions of all of the extraocular muscles depend on the position of the eye as each undergoes contraction. The vertical recti muscles run along the same line as the orbital axis, thereby also creating an angle of 23 degrees with the visual axis at their attachment point anterior to the equator. When the globe is abducted 23 degrees, the vertical recti muscles act purely to elevate or depress the eye.

Question 53

In order to maintain binocular fixation and fusion on a target that is moved away from the patient in a linear fashion, assuming the target moves in one plane only, which of the following ocular movements must occur?

Dextroversion of the right eye and levoversion of the left eye

Divergence

Infraversion

Supravergence

Answer 53

Divergence

In order to maintain fixation on a target that is moved away from the patient, his eyes must diverge (rotate outwards away from the midline). A vergence is a binocular movement of the eyes such that the eyes move in opposite directions. A version is a binocular eye movement in which the eyes move in the same direction and of equal magnitude. Infraversion is a movement where both eyes look downwards. Although during divergence, the right eye technically moves slightly to the right (away from the midline) and the left eye moves slightly to the left (away from the midline) these movements cannot be termed dextroversion and levoversion respectively as a version infers movement of the eyes in the same direction. Supravergence is the movement of one eye upwards with respect to the other.