Paeds: Amblyopia 2 (tx) - Week 3 Flashcards
How does treatment style of amblyopia differ in the U.S compared to Australia? Explain these choices
Australia: majority patching
U.S: majority atropine
According to the lecturer: the U.S is more concerned with appearances and fitting in, while parents in Australia are less keen to have drops in their child’s eye. (considered like a poison)
Regardless, results are similar
Name 1 benefit for using atropine over patching for amblyopia treatment. In what population would this be most useful?
Child can’t take out the atropine drop.
- most useful for children younger than 2.5 yo who won’t wear a patch
What did PEDIG ATS 1A investigate and what did it find? Include: frequency, level of amblyopia, and age of children.
Atropine versus Patching for treatment of Moderate Amblyopia (6/12-6/30) in (3-7yo) children:
- Daily atropine vs patch 6+ hrs/day
Results:
- Atropine 2.84 lines improvement @ 6months
- Patch 3.16 lines @ 6months
- 3.7 vs 3.6 lines @ 2 years
So VERY SIMILAR results
What did PEDIG ATS 2A investigate and what did it find?
Part time (6 hours) versus full time patching for Severe Amblyopia (6/30-6/120) (in children 3-7yo)
Results:
- Part time: 4.8 line improvement @ 4 months
- Full time: 4.7 line improvement @ 4 months
VERY SIMILAR.
What did PEDIG ATS 2B investigate and what did it find? [MOST IMPORTANT PAPER]: how much did each group improve by? and how did the rate of improvement in each group compare?
Part time (6 hours) versus Minimal-time (2 hours) patching for Moderate amblyopia (6/12-6/24) in children under 7yo
Results:
- Part time: 2.4 line improvement @ 4 months
- Minimal time: 2.4 line improvement @ 4 months
- rate of improvement was the same for each group
EXACTLY THE SAME - 2 hours works just as well as 6 hours
What is a useful way to suggest part time occlusion with patching in a paediatric consult?
Good to suggest 3 hours instead of 2, as the child will inevitably do less than you ask
Is 2 hour/day patching a good long term therapy for amblyopia treatment? Explain
No. A very small percentage of 2 hour patching patients actually got to 6/6 acuity in ATS2B (10%). Compare this will full time occlusion over 2 years from Beardshell’s study where 53% got to 6/6 acuity.
So part time occlusion works well for the first few months or until the acuity is 6/12 or better
What did PEDIG ATS 15 investigate and what did it find?
Increasing patching for amblyopia.
- 6 hours patching for 12 weeks post stable acuity with 2 hour patching
- children 3-8yo
Results:
- Control: 0.5 lines @ 10 weeks
- Treatment: 1.2 lines @ 10 weeks
Does part time occlusion (2 hours) work for minor amounts of amblyopia?
Not really
What is Recidivism? When is this more likely to occur (2)
Some amblyopes get worse once we stop treatment.
More likely if:
- younger child (<11yo. Still within amblyopic window)
- cause of amblyopia not treated
What did PEDIG 2C investigate and what did it find? Explain incidence over time
Risk of amblyopia recurrence after cessation of tx.
- children were followed up over a period of 56 weeks
- recurrence defined as 2 line drop
Results:
- 21% of patients recurred in 1 year (56 weeks)
- 3% of patients had 2 line drop but wasn’t replicated
- 70% of these two sets of patients happened in first 3 months
How can we find the 25% of amblyopia reccurrence?
After cessation of tx, review @ 1 month, 3 month, 6 month, then yearly
How do you define a failure in amblyopia treatment? What percentage of amblyopia treatment fails in private practice?
Failure defined as less than 6/12 acuity.
15% of children in private practice will fail.
Why does amblyopia treatment fail? (3)
Compliance (vast majority)
Unknown reasons
Eccentric fixation (no treatment effective for this)
Define penalization
Reduce resolution of input of dominant eye (rather than totally blocking out)
- involves removing high frequency (high acuity) data
Will penalization work with dense amblyopia?
No. You’d need a patch instead.
What level of acuity do you generally want in the amblyopic eye for penalization to work?
Generally want 6/12 or better.
(This is convenient because that’s when you’d stop part time patching, so you can go straight from patching to penalization)
How much do you need to blur the dominant eye in penalization for the patient to swap fixation?
3 or more lines of blur. Magic number = 4 lines
List the 3 types of penalization?
Fogging
Atropine
Bangerter or Cling Foils
How does blurring of the eyes differ between fogging and atropine?
Fogging: Add +1 to +3 to blur dominant eye @ distance
Atropine: Blurs dominant eye @ near
Compared to other types of penalization, is atropine appropriate for school aged children? Why/why not?
Not really. It makes them read with their non-dominant eye and could impact reading, so consider this a last resort
How does atropine compare to fogging in terms of visual acuity requirements?
Fogging: generally requires at least 6/12 acuity for adequate compliance (preferably 6/9)
Atropine: 6/30 or better. Especially 6/24 or better (i.e. most amblyopes)
What is the typical add we prescribe in fogging? Explain reasoning
+1.50. Works great. The more you go over that, the more likely the patients say your glasses are too blurry (compliance). Any lower and patient may not change fixation
Why may fogging be preferable to atropine?
Cosmetics. Nobody will know the difference so really good over the long term for full time treatment.
[lecturer recommends fogging post patch]
Explain how atropine therapy works
1 drop of 1% atropine to dominant eye either daily or once a week to blur dominant eye @ near, causing amblyopic eye to fixate
What did PEDIG ATS4 investigate and what did it find?
Daily vs Weekend atropine usage for 6/12-6/24.
Results
- SAME
- daily slightly easier to do (habit forming)
Describe Bangerter/Cling foils
Is applied to dominant eye. Is like contact plastic. Translucent and gives an effect like a shower screen (as things get further away they get blurrier).
[lecturer is not keen on them]
