Strabismus Measurements

Question 1

An examiner could use a __ while testing versions. Patient can then tell the examiner if white/ red light separate at any point to see if an incomitant deviation is presented.

Answer 1

Red lens

Question 2

_ is eye a miss alignment or eyes that do not move normally caused by intocular muscle in balance. One fovea is not directed at the same object as the other can be congenitald or acquired

Answer 2

Strabismus

Question 3

Strabismus can include

Answer 3

Accommodative strabismus 
Alternating 
Comitant 
Incomitant
Intermittent 
Paralytic

Question 4

cause “ risk factors” of strabismus

Answer 4

Family history
Refractive error
Medical conditions

Question 5

_ caused by focusing efforts of the eyes trying to see clearly highly influenced by accommodative effort example;accommodative esotropia

Answer 5

Accommodative strabismus

Question 6

Focusing on a stimulus at near causes miosis, accommodation and convergence. This is known as the_ 

Answer 6

Synkinetic near response

Question 7

Types of accommodative esotropia include:

Answer 7

refractive, non-refractive and partially accommodation

Question 8

_ can be from significant uncorrected hyperopia which forces the patient to exert excessive accommodation to focus images on the retina that’s causing increased convergence

Answer 8

Accommodative esotropia

Question 9

-_ is when fixation and deviation alternate meaning either eye fixates in primary position (fixation held for 30-60 secs or more)vision typically is equal between the two eyes

Answer 9

Alternating tropia

Question 10

_ The degree of eye misalignment is the same in all directions of the gaze

Answer 10

Comitant strabismus

Question 11

_ is a term to describe a degree of misalignment that varies in different positions of gazes ( head tilt/turn typically to the null point)

Answer 11

Incomitant strabismus

Question 12

_ A deviation in which the eyes are sometimes straight and other times an eye deviates

Answer 12

Intermittent strabismus

Question 13

A_ is hidden or latent that occurs when the eye is deprived of a fixation target ( eye is covered- break fusion for the deviation to occur)

Answer 13

Phoria

Question 14

With _ The degree of eye misalignment varies with positions of gaze(incomitant) and results from the paralysis or weakness of one or more extraocular muscles or nerves

Answer 14

Paralytic strabismus

Question 15

( eye turned lateral) crossed diplopia

Answer 15

Exo

Question 16

eye is turned medial ( uncrossed diplopia )

Answer 16

ESO

Question 17

Eye is turned superiorly

Answer 17

Hyper

Question 18

Eye is turned inferiorly

Answer 18

Hypo

Question 19

We always record the higher eye

Question 20

A _ is a Manifest Eye turn or deviation caused by extraocular muscle imbalance that the patient has no or very little control over. The patient is unable to keep the eye Straight with the power of fusion readily observable

Answer 20

Tropia

Question 21

_ is the amount of deviation when the non-affected eye is fixating. _ is the amount of deviation when the paretic eye is fixating

Answer 21

Primary deviation

Secondary deviation

Question 22

If a _ Is forced to take up fixation in the field of the under acting muscle it will result in over action of its yolk muscle because there is additional innervation sent to the weakened muscle to function. Due to hering’s law this additional innervation causes the yoke muscle ( of the non-paretic eye) to become overactive and it’s said to a secondary deviation

Answer 22

Paretic eye

Question 23

Primary deviation is measured by holding the prism over the

Answer 23

Deviated eye

Question 24

Secondary deviation are measured with cross-cover and prims , by holding the prism over the _

Answer 24

Fixating eye

Question 25

The _ deviation is typically greater (in relation to prism diopters of deviation) than the primary deviation

Answer 25

Secondary

Question 26

Right exotropia

Answer 26

RXT

Question 27

Left exotropia

Answer 27

LXT

Question 28

Right esotropia

Answer 28

RET

Question 29

Left esotropia

Answer 29

LET

Question 30

Right hypertropia

Answer 30

RHT

Question 31

Left hypertropia

Answer 31

LHT

Question 32

Exophoria

Answer 32

X

Question 33

Esophoria

Answer 33

E

Question 34

Right hyperphoria

Answer 34

RH

Question 35

Left hyperphoria

Answer 35

LH

Question 36

Intermittent tropia

Answer 36

Deviation with (T)

Question 37

Alternating tropia

Answer 37

Alt

Question 38

A pt who does not demonstrate a deviation of eye alignment is termed _ or _ which is the absence of eye deviation.

Answer 38

Ortho , orthophoric

Question 39

Motility testing is typically done with _ so that the pt can fixate on the accommodative target at both distant and near

Answer 39

Best corrected visual acuity (BCVA)

Question 40

_ is the angle created between the visual axis ( an imaginary line that connects fixation to the fovea) and the pupillary axis ( center of the curvature or the cornea and pupil)

Answer 40

Angle kappa

Question 41

_ corneal reflex falls nasal to the center of the pupil ( in both eyes if pt is ortho and in then fixating eye is a tropia is present)

Answer 41

Positive angle kappa

Question 42

_ is when the corneal reflex falls right on the center of the pupil

Answer 42

No angle kappa

Question 43

_ corneal reflex falls temporally to the center of the pupil ( in both eyes if pt is ortho and fixating eye if a tropia is present) may give an illusion of an eso deviation

Answer 43

Negative angle kappa

Question 44

The hirschberg test states one millimeter of reflex displacement equals approximately _ of eye alignment deviation which is based on the average pupil size of 4mm

Answer 44

7 degrees or 15 prism diopters

Question 45

The _ uses prisms following the Hirshberg test to move the deviated reflex back into the position that is symmetrical with the reflex of the fixating Eye as it means of measuring the deviation

Answer 45

Krimsky test

Question 46

Hirschberg is an _ based on mm of decentration while krimsky is the _

Answer 46

Estimation, measurement of deviation with prisms

Question 47

_ gives the appearance of esotropia due to: less visible sclera, epicanthal folds, and/ or bridge of the nose. Hirschberg proves ortho

Answer 47

Pseudoesotropia

Question 48

Hirschberg and krimsky test use an _ target and can be check at both _ and _

Answer 48

Accommodative, distant and near

Question 49

Light reflex’s on cornea

Answer 49

``` Center: Normal Medially: exotropia Laterally: esotropia Inferiorly: hypertropia Superiorly: hypotropia ```

Question 50

Hirschberg light reflex displacement is as follows

Answer 50

Pupillary boarder 2mm=15 degrees = 30 prism diopters Mid iris is 4mm= 30 degrees =60 prism diopters Limbus is 6mm= 45 degrees = 90 prism diopters

Question 51

Corneal reflex is temporally you hold prism over the eye _ . Nasally _ superiorly _.

Answer 51

BO, BI, BU, BD

Question 52

Cover testing includes three types which are _

Answer 52

Cover-uncover test, the alternate cover test and the simultaneous prism cover test

Question 53

The _ is the test used to detect binocular fixation and rule out tropia or distinguish between a tropia and a phoria . It allows the patient to establish binocular fixation if possible. If there is no binocular fixation there is no tropia

Answer 53

Cover- uncover test

Question 54

The _ is the only test that will differentiate a tropia from a phoria!

Answer 54

Cover uncover test

Question 55

When looking for a tropia watch the _ as soon as you cover the opposite eye to see if it moves to pick up fixation . When tropia is present, once fixating eye is covered the tropic eye will move _

Answer 55

Uncovered eye , towards fixation

Question 56

_ aka _ follows cover uncover testing (if no tropia ) and is used to bring out a phoria where one must alternate cover ( w occluded) _ times

Answer 56

Alternating cover test , cross cover test , 10-12 times

Question 57

Not finding any phoria or tropia with cover uncover test

Answer 57

Ortho

Question 58

When measuring a deviation with prism the apex of the prism points _ over the deviated eye

Answer 58

Vertical/ horizontal

Question 59

Reasons to preform cover testing

Answer 59

Pt reports diplopia Pt reports difficulty reading Pt states they can’t read for long time Complete exam

Question 60

Purpose of cover uncover test and cross cover test includes

Answer 60

Tropia or phoria ( cover uncover test) To see if a pt is fusing/both distance and near If there is deviation once fusion is broken

Question 61

_ is a condition when an eye drifts upward which may vary during the course of day unilateral or bilateral deviation ( can be unequal and not at the same time)

Answer 61

Dissociated vertical divergence

Question 62

_ is preformed by simultaneously covering the The fixating eye at the same time the prism is placed in front of the Deviated eye. Test is repeated increase in prison powers until the deviated Eye no longer moves

Answer 62

Dissociated vertical deviation (dvd)