What are the 5 Characteristics of ET?

When do these not apply?

-mostly constant

-frequently amblyiogenic

-many will not develop high grade stereopsis or binocular vision

-refractive error is either partly or totally causative, usually a higher incidence of hyperopia

-will respond poorly to orthoptics/VT (hard to train NFV)

-when the patient is not neurologically normal

-infantile

-accommodative (refractive, non-refractive, partly accommodative)

-non-accommodative

-secondary (sensory, consecutive)

-microtropia (small-angle, <10 PD)

-cyclical

-mechanically restrictive or paretic

What is infantile esotropia?

When does it begin?

What is the old term for this?

-an esotropia that develops in a neuroligically normal child -before the age of 6 months, probably between 2-4 months of age

-congenital

What is the most common ocular deviation among newborns?

What happens to this deviation as they increase in age?

What deviaitons are likely to not decrease with age?

-XT and IXT

-CXT and IXT decrease during the first few months of life

-ESO-EXO and ESO deviations do not decrease with age

What is the incidence of infantile esotropia?

These numbers are likely ______.

What are some significant factors that increase the likelihood of infantile ET?

-28-54%

-overestimation

-low APGAR scores, low birth weight, premature birth, family members with hx of strab

-pseduoesotropia

-Duane's syndrome

-abducens nerve palsy (LR palsy)

-sensory ET (organic lesion)

-ET of non-neurologically normal child

-accommodative ET

What magnitude and frequency do you expect of an infantile ET?

Is it present at distance and near?

What do you expect of the refractive error?

What percentage of infantile esotropes manifest >2D of hyperopia?

What is the mean RE of hyperopia in infantile ETs?

The RE is skewed toward ___, but not ___ ____. 

-50%

-2.50 D

-hyperopia, high hyperopia

Will infantile ET's have amblyopia?

What % of the time?

What other problems might be observed in these patients?

-yes

-40%

-ocular motility problems

What ocular motility problems might you expect in an infantile ET?

What do you expect to see on EOMs in patients with infantile esotropia? What is this caused by?

Is there truly limited abduction? How can this be determined?

-limited abduction

-oblique muscle dysfunction

-dissociated vertical deviation

-latent nystagmus

-cross of crossed fixation- when the penlight is the the childs right, the fix and follow with the left eye; when the penlight is to the child's left, they fix and follow with the right eye (alternate fixation)

-no, because when monocular ductions are performed the eyes abduct just fine

Would you expect amblyopia in a child with cross/crossed fixation?

What two clinical tests can determine if there is truly an abduction problem?

-no, because they alternately fixate

-Doll's head and monocular ductions

What % of infantile ETs show ___ -oblique muscle ____-action?

What % of children with infantile ET have DVD?

DVD disobeys what law?

Is this pathognomonic for iET?

-70%, inferior, overaction

-50% of all cases

-Herings law of equal innervation

-no

What is latent nystagmus?

How might this affect VA?

The slow phase rotation is directed toward ___ and fast-phase rotation directed toward the ___. 

How should amblyopia be treated in a patient with latent nystagmus?

-a binocular horizontal nystagmus that becomes manifest when one eye is covered

-monocular VAs will be worse than binocular VAs

-nose, ear

-atropine

What is the speculative etiology of iET?

What are 5 strabismogenic factors?

-congenitally defective vergence system (motor fusion defect)

-excessive tonic convergence, high AC/A, hypermetropia, anisometropia, unknown

The natural course of the disease is ___. 

Some reports suggest some may experience what?

This is more common in iET patients with what?

-stable

-spontaneous resolution

-small and variable deviations

What is the first step of treatment in iET?

Is it likely the ET will resolve with this alone?

-optimal RE correction (hyperopia >/= 2.50D, anisometropia, astigmatism)

-no

How is amblyopia treated in these patients?

When should it be treated?

What is a goal that patching hopes to accomplish in iET patients?

Will prisms be helpful in these children?

-patching

-after optical correction, but before ocular alignment treatment

-alternate fixation in those with unilateral preference

-NEVER

How is ocular alignment achieved in iET?

What is the goal of this treatment?

What percentage will need more than one sx?

Does this mean that the patient will be ortho post surgery?

Will the patient be able to gain fusion?

-EOM sx

-10 PD +/- of ortho

-32.4% 92.1 sx on average)

-may develop some fusion

What is the BV prognosis for iET after txt?

What does prognosis depend upon?

What does early surgery minimize?

At what age should this be done?

-peripheral fusion is usually the best sensory outcome

-age at surgery- early is better for BV

-minimizes period of misalignment and has a better chance of obtaining BV

-less than 6 months

If ocular alignment is acheived before ___ months, there is a greater chance for what to be acheived?

The longer the duration of misalignment, what happens to chances of developing stereopsis?

-24 months; fusion of stereopsis

-they are significantly reduced

What is the % of stereopsis development for pts with ocular alignment at 0-6 months?

7-12 months? 12-24 months?

___ % develop a stereopsis quality of ___ secs or better?

-80%

-80%

-58%

-48%(0to12)-41%(12-24); 800 

Infantile ET is a "____ ____". 

What are some residual effects that follow txt of iET?

-lifetime sentence

-recurring strabismus (AET, CET)

-Amblyopia- post-txt

-DVD

-oblique muscle dysfunction

-reduced stereopsis

In the long-term follow-up for iET, when were patients more likely to need a second surgery?

Which patients were more likely to need a second surgery?

What was the level of correction for most patients?

What portion had measurable stereopsis?

What percentage of these patients showed a microstrabismus?

-after 10 years

-those with large angle strabs that had surgery earlier in life

-within 8PD of ortho

-1/3 with measurable stereo

-50%

What is an accommodative esotropia?

What is this attributed to?

What happens when a patient accommodates?

Who first described this?

-an acquired esotropia due to activation of the accommodative reflex

-abnormal high AC/A ratio and uncorrected hyperopia

-accommodation stimulates near reflex and over-converges the eyes

-Donders in 1864

How is AET different from other ETs?

___ plays a more important developmental factor here than in infantile ET/XT.

What perecentage of children acheive either complete resolution or significant reduction in ET with correction in AET?

-ET is either totally eliminated or reduced by 10PD or more with optimal optical correction (spec Rx or bifocals)

-heredity (strong component)

-50%

What is the most common pediatric strabismus?

What is the second most common?

What is the prevalence of AET in the U.S.?

What percentrage of 1st degree relative will have AET?

2nd degree relatives? 3rd degree?

-AET

-IXT

-1-2%

-25%; 12%; 2-3%

What is the average age of onset of AET? What is the age range?

Can occur as early as ___, or as late as ____.

-2.5 yrs; 1-8 years

before 6 months, adolescence

What are the differential diagnoses of AET?

What are the 3 AET subtypes?

Which is the most common? Which is the least common?

-pseduo-ET

-RAET- refractive (most common) 

-Non-RAET- non-refractive (least common) 

-PAET- partly or mixed accommodative ET 

When does RAET exist?

What is the usualy amount of RE in RAET? Mean?

What might happen with higher hyperopia?

If amblyopia develops, how severe is it and in what cases will this happen?

-when optimal hyperopic RE correction eliminates ET at all distances 

-2-6D; 4D

-the patient does not accommodate appropriately and isoametropic amblyopia develops

-mild, limited to cases with significant anisometropia and or cases that become constant or unilateral prior to treatment

The AC/A has an ___ relationship to the amount of hyperopia?

If the AC/A is high, what amt of hyperopia is likely to cause an AET? If the AC/A is normal, what amt of hyperopia is likely to cause an AET?

What will happen in patients with an innately low AC/A ratio?

-inverse

-2.25D ; 4.75D

-they will not develop an AET

In RAET, what is the magnitude of the AET?

The ET may be larger at ___ than at ___. What is this likley dependent on?

What is the median ET at distance and near?

What do you expect of retinal correspondence and ocular motility in RAET?

-10-35 PD (mild to moderate in size)

-AC/A ratio

-near, distance

-25, 27.5 respectively

-NRC (synoptophore); ~35% will manifest an oblique muscle dysfunction

What is the course of the development of the ET?

What should you think initially if you see an IET in a neurologically normal child?

-starts out as intermittent and variable and will likely become constant if untreated

-RAET