4. Intermittent Esotropia Flashcards
What is esotropia?
Manifest deviation where misalignment of the visual axis results in inward turning of one eye.
4 groups of esotropia?
- Primary (Constant and intermittent)
- Secondary/ sensory
- Consecutive
- Residual
What is Secondary/ sensory esotropia?
Strabismus is secondary to another reason e.g. poor VA.
What is consecutive esotropia?
Was an exotropia but due to surgery now an esotropia (over correction).
What is residual esotropia?
Px had big esotropia but after surgery left with small esotropia.
What is intermittent esotropia and what are the 4 classifications?
Esotropia only present under certain conditions, when eyes are straight normal BSV. related to the following classification: Distance, Time, Accommodation, Non-specific.
Most common is related to accommodation.
Risk of amblyopia with intermittent esotropia is high or low?
Low risk because px doesn’t need to be straight 24/7 and be binocular for VA to develop normally.
2 categories of intermittent esotropia?
- Fully accommodative esotropia
- Convergence excess esotropia
What is fully accommodative esotropia and what are the characteristics?
- Constant esotropia when hyperopia is uncorrected.
- Presenting at 18months to 3years.
- Hyperopic +3 to +6
- Px is straight when Rx corrected.
- Management: Wear fully corrected RX, surgery not needed.
- VA likely to be equal or squinting eye likely to be slightly amblyopic.
What is the max when undercorrecting big plus?
+2D
Why is the range for fully accommodative esotropia +3D-+6D?
A higher plus (+8D-+10D can’t accommodate readily without RX being corrected). Big plus: the RX is to high to produce an esotropia.
What happens when full correction given to fully accommodative esotropia?
Eliminates accommodation and reduces convergence.
Why is slight amblyopia present in fully accommodative esotropia?
Prior to dispensing glasses the child will have constant esotropia therefore potential for amblyopia to develop.
What is convergence excess esotropia?
Onset?
Are they likely to be amblyopic?
Esotropia at near but straight with BSV at distance. With RX corrected still esotropic at near. Related to high AC/A ratio
Onset: 2-5 yrs.
VA likely to be equal for BEs hence low risk of amblyopia.
Cause of convergence excess esotropia?
High AC/A ratio: Hence, accommodating by a normal amount can induce a large amount of accommodation convergence, hence large eso deviation.
Management of convergence excess esotropia- long term & short term
Short term: Executive bifocals with a +3.00Add as px is waiting for surgery. This allows the child be binocular and surgery is the permanent way to reduce large AC/A values.
What are the 2 classes of intermittent esotropia relating to distance?
- Near Esotropia
- Distance Esotropia
What is Near Intermittent esotropia?
Esotropia present at near fixation, straight BSV at distance. Unrelated to refractive error or accommodation.
What is distance intermittent esotropia?
Esotropia present at distance fixation, straight BSV at near. Unrelated to refractive error or accommodation.
Management of intermittent esotropia’s relating to distance?
Management is usually surgical if cosmesis is poor.
How to differentiate near esotropia from convergence excess?
Place a +3.00D lens + CT, if angle becomes straight/ phoric– suggests px has a high AC/A ratio hence, convergence excess. With +3 no difference = Near esotropia.
How to differentiate between near esotropia and 6th nerve palsy?
Bot h have a near esotropia, hence look at motility to differentiate.
6th nerve palsy= When px looks out, limited abduction (Esotropia will be significantly big) of affected eye because lateral rectus in affected eye is weak.
Distance eso = complete full motility.
Do you refer a 6th nerve palsy?
YES URGENTLY
What is cyclic esotropia?
Are they likely to be amblyopic?
Esotropia related to time. Esotropia present a regular intervals. Usually requires surgery.
Not likely to be amblyopic because px is binocular at most times.
What is non-specific esotropia?
No confirmed pattern
