Uncovering ATS-1

The advantage of the Amblyopia Treatment Studies is that

they are large multi-center prospective studies that can help guide us on how to improve VA with different treatment options in patients with amblyopia. The downside with the studies is that they deal almost exclusively with improvements in VA and they have had a difficult time, due to many potential factors, evaluating the impact of vision therapy and surgery. While some of these studies are a few years old, I often get questions about the specifics of the study. Let's take a deeper dive:

Clinical Question: In patients with moderate amblyopia is patching or penalization more effective in patients aged 3-7 years old? (Answer: ATS-1)
  • 419 children with amblyopia (20/40 to 20/100) were randomized to:

  • 215 patching (6 hours to full time)

  • 204 atropine (1% QD)

  • Baseline mean VA in the amblyopic eye: 20/63

  • Baseline mean difference in acuity between eyes: 4.4 lines

  • VA Improvement:

  • Six Months Mean VA:

  • Patching: 20/32

  • Atropine: 20/32-2

  • Improvement initially was faster in the patching group, but after six months, the difference in acuity between treatment groups was small

  • Two Year Mean VA:

  • Patching: + 3.7 lines

  • Atropine: + 3.6 lines

Clinical Pearls ATS-1

  • Both treatments were well tolerated, although atropine had a slightly higher degree of acceptability on a parental questionnaire

  • At 6 months it is slightly more likely for patients taking atropine to have reduced acuity in the sound eye at six months but this did not persist with further follow up

  • Patching advantage: more rapid improvement in VA and possibly a slightly better acuity outcome

  • Atropine advantage: easier administration and lower cost

  • If one treatment doesn’t work consider switching to the other

  • Initial choice of patching or atropine can be made by the provider and parent

15 Year follow up found:

  • Mean amblyopic-eye acuity (147 subjects): ~20/25

  • 60% of amblyopic eyes were 20/25 or better

  • 33% of amblyopic eyes were 20/20 or better

  • Mean interocular acuity difference: 2.1 lines

  • 48% of subjects had an interocular acuity difference of 2 or more lines

  • 71% of subjects had an interocular acuity difference of 1 or more lines

Have a great week ~Chris