Paeds: Optometric Mx of EsoT STRAB - Week 5 Flashcards
List 6 differential diagnoses of EsoT
Accommodative EsoT
Non-accommodative EsoT
Pseudo-EsoT
Infantile EsoT
Duane’s syndrome
Pathological STRAB (6th palsy or other)
List and describe correction for the 3 subgroups of accommodative EsoT
Totally accommodative EsoT: near add fully corrects
Partially accommodative EsoT: near add partially corrects (I.e. corrects >/=50%)
Accommodative excess: EsoT N>D. Correct with distance Rx for distance + near add for near
Which type of EsoT is the most common type of strabismus?
Accommodative
Suppose a child has R +3 and L +4 DS. Which eye will she typically choose for clear vision? Why
Right eye. Usually choose to accommodate the least amount for clear vision, because our system is lazy
List 3 reasons for when you should prescribe spectacles for EsoT
Hyperopia > +2
EsoT responds to plus lenses (positive Raab +3 test)
Hyperopia < +2 BUT high AC/A (indicates C.E)
What is Gunter Von Noorden’s general policy for strabismic hyperopic correction?
“It is our policy to correct all strabismic hyperopes over +2.50 before considering surgery” (i.e. without even needing to look at anything else)
(NB: this is for atropine, when using cyclopentolate change +2.50 to +2.00)
Describe the Raab +3 test
Checks for accommodative component to strab/EsoT
Add +3.00 lenses in front of patient’s eyes and direct them to a near target. Look at position of eyes. If position changes with lenses in place = there is an accommodative component to this strab/EsoT.
If prescribing a bifocal for children with accommodative EsoT, where should the segment be located?
segment should be prescribed on the datum/middle of the frame
List 3 complications in diagnosing EsoT in the first visit
Won’t necessarily find all the hyperopia
EsoT may respond better to plus after a few weeks
Motor examination is done before cycloplegic and cannot be reliably repeated on the day (as accomm. is paralysed)
What is the dosage used for cycloplegia in children? If older than 6 months or under 6 months?
Under 6 months: 0.5%
Over 6 months: 1%
How long should you wait after cyclopleging children to perform retinoscopy?
40 minutes
How much more plus is revealed by atropine compared to cyclopentolate?
Reveals 0-0.50D more plus.
List 1 advantage and 1 disadvantage of atropine
Adv: does not sting (great for kids)
Disadv: takes 4-6 hours to give adequate cycloplegia
Kowal: ET and high hyperopia study (ARVO 2008) of 86 hyperopic toddlers with >+6 diopters and EsoT:
In a mean follow up period of 20 months, what happened to the hyperopia of these patients after prescription with full cyloplegic?
36% showed increase in hyperopia >1.25 diopters
(NB: the lecturer’s practice found an average change of refraction of +1.00DS in an 8 year follow up with a different cohort)
For what percentage of paediatric patients will you not have found all the plus on initial consult? What does this mean?
25-50%. This means you need to confirm whether you have found all the plus at reviews (NB: should use two different measures for this e.g. ret + max plus)
If you have found all the plus, what should you expect to see for VA when blurring?
+0.50 over Rx should reduce VA by at least a line
Should you put plus in front of the fixating or non-fixating eye?
Fixating eye. Putting plus in front of the fixating eye will keep the strabismic eye straight
So prescribe full plus to the dominant eye to treat starbismus
What happens to a child with accommodative EsoT if nothing is done in the first few weeks? (4)
- Child learns to accommodate and break fusion to make retinal image clearer in dominant eye
- Intermittent EsoT becomes constant
- Suppression develops in first few days-weeks
- Amblyopia develops in first few weeks
What happens to a child with accommodative EsoT if nothing is done in the first 2 years? (2)
- Change in #/size of sarcomeres in medial/lateral rectus (i.e. changes to non-accommodative EsoT) in 6-12 months
- Anomalous correspondence develops in first few weeks peripherally and centrally after 1-2 years
What is the end result of not treating a child with accommodative EsoT for 2 years?
EsoT no longer responds to plus lenses either completely or partially
List 4 important scenarios where you should do a cycloplegic ret? (as dry ret is only an estimation here)
EsoT px
Under 3 yo
Plus >2.50
Spectacle virgin
How does the dry ret compare to wet ret if patient wearing close to full plus?
they will be the same
How does the prescription of plus differ between children and presbyopes?
Presbyopes: least plus that’ll make them happy
Children: max plus/full plus on cycloplegic no matter how high. Even when very high plus there is still a very low rejection rate
Is max plus about clear vision?
No! instead of saying tell me when it’s clear. You should ask: “tell me when you can’t read the letters”
List the 5 principles of treatment of any EsoT (from lionel kowal)
- Give full plus [cycloplegia]
- Rx any amblyopia
- Plus for amblyopic eye is for vision
- Plus for fixating eye is for EsoT
- Consider realignment for any residual EsoT after best amblyopia result and plus has been re-checked
When do we perform surgery for EsoT? What is the aim of this surgery?
When there is still a cosmetic defect despite wearing full plus (i.e. EsoT >/= 15p.d).
Aim = to provide acceptable cosmetic appearance
What is defined as cosmetically acceptable strabismus?
+/-10p.d
Will the child still have to wear glasses after EsoT surgery?
Yes if there is more than 2D of hyperopia
What percentage of EsoT surgery patients have straight eyes at 1 month? What is the long term success rate with one operation?
80%. However, 30% of this group will need a second operation within a few years
Long term success with one operation is 55%
