Paeds: Amblyopia 2 (tx) - Week 3

Question 1

How does treatment style of amblyopia differ in the U.S compared to Australia? Explain these choices

Answer 1

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

Question 2

Name 1 benefit for using atropine over patching for amblyopia treatment. In what population would this be most useful?

Answer 2

Child can’t take out the atropine drop.
- most useful for children younger than 2.5 yo who won’t wear a patch

Question 3

What did PEDIG ATS 1A investigate and what did it find? Include: frequency, level of amblyopia, and age of children.

Answer 3

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

Question 4

What did PEDIG ATS 2A investigate and what did it find?

Answer 4

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.

Question 5

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?

Answer 5

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

Question 6

What is a useful way to suggest part time occlusion with patching in a paediatric consult?

Answer 6

Good to suggest 3 hours instead of 2, as the child will inevitably do less than you ask

Question 7

Is 2 hour/day patching a good long term therapy for amblyopia treatment? Explain

Answer 7

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

Question 8

What did PEDIG ATS 15 investigate and what did it find?

Answer 8

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

Question 9

Does part time occlusion (2 hours) work for minor amounts of amblyopia?

Answer 9

Not really

Question 10

What is Recidivism? When is this more likely to occur (2)

Answer 10

Some amblyopes get worse once we stop treatment.
More likely if:
- younger child (<11yo. Still within amblyopic window)
- cause of amblyopia not treated

Question 11

What did PEDIG 2C investigate and what did it find? Explain incidence over time

Answer 11

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

Question 12

How can we find the 25% of amblyopia reccurrence?

Answer 12

After cessation of tx, review @ 1 month, 3 month, 6 month, then yearly

Question 13

How do you define a failure in amblyopia treatment? What percentage of amblyopia treatment fails in private practice?

Answer 13

Failure defined as less than 6/12 acuity.

15% of children in private practice will fail.

Question 14

Why does amblyopia treatment fail? (3)

Answer 14

Compliance (vast majority)
Unknown reasons
Eccentric fixation (no treatment effective for this)

Question 15

Define penalization

Answer 15

Reduce resolution of input of dominant eye (rather than totally blocking out)
- involves removing high frequency (high acuity) data

Question 16

Will penalization work with dense amblyopia?

Answer 16

No. You’d need a patch instead.

Question 17

What level of acuity do you generally want in the amblyopic eye for penalization to work?

Answer 17

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)

Question 18

How much do you need to blur the dominant eye in penalization for the patient to swap fixation?

Answer 18

3 or more lines of blur. Magic number = 4 lines

Question 19

List the 3 types of penalization?

Answer 19

Fogging
Atropine
Bangerter or Cling Foils

Question 20

How does blurring of the eyes differ between fogging and atropine?

Answer 20

Fogging: Add +1 to +3 to blur dominant eye @ distance
Atropine: Blurs dominant eye @ near

Question 21

Compared to other types of penalization, is atropine appropriate for school aged children? Why/why not?

Answer 21

Not really. It makes them read with their non-dominant eye and could impact reading, so consider this a last resort

Question 22

How does atropine compare to fogging in terms of visual acuity requirements?

Answer 22

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)

Question 23

What is the typical add we prescribe in fogging? Explain reasoning

Answer 23

+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

Question 24

Why may fogging be preferable to atropine?

Answer 24

Cosmetics. Nobody will know the difference so really good over the long term for full time treatment.

[lecturer recommends fogging post patch]

Question 25

Explain how atropine therapy works

Answer 25

1 drop of 1% atropine to dominant eye either daily or once a week to blur dominant eye @ near, causing amblyopic eye to fixate

Question 26

What did PEDIG ATS4 investigate and what did it find?

Answer 26

Daily vs Weekend atropine usage for 6/12-6/24.

Results
- SAME
- daily slightly easier to do (habit forming)

Question 27

Describe Bangerter/Cling foils

Answer 27

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]