Strabismus Measurements Flashcards
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.
Red lens
_ 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
Strabismus
Strabismus can include
Accommodative strabismus Alternating Comitant Incomitant Intermittent Paralytic
cause “ risk factors” of strabismus
Family history
Refractive error
Medical conditions
_ caused by focusing efforts of the eyes trying to see clearly highly influenced by accommodative effort example;accommodative esotropia
Accommodative strabismus
Focusing on a stimulus at near causes miosis, accommodation and convergence. This is known as the_ 
Synkinetic near response
Types of accommodative esotropia include:
refractive, non-refractive and partially accommodation
_ 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
Accommodative esotropia
-_ 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
Alternating tropia
_ The degree of eye misalignment is the same in all directions of the gaze
Comitant strabismus
_ is a term to describe a degree of misalignment that varies in different positions of gazes ( head tilt/turn typically to the null point)
Incomitant strabismus
_ A deviation in which the eyes are sometimes straight and other times an eye deviates
Intermittent strabismus
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)
Phoria
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
Paralytic strabismus
( eye turned lateral) crossed diplopia
Exo
eye is turned medial ( uncrossed diplopia )
ESO
Eye is turned superiorly
Hyper
Eye is turned inferiorly
Hypo
We always record the higher eye
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
Tropia
_ is the amount of deviation when the non-affected eye is fixating. _ is the amount of deviation when the paretic eye is fixating
Primary deviation
Secondary deviation
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
Paretic eye
Primary deviation is measured by holding the prism over the
Deviated eye
Secondary deviation are measured with cross-cover and prims , by holding the prism over the _
Fixating eye