3. Amblyopia treatment
◦ Eliminate the obstacle to vision (i.e.
cataract etc)
◦ Correct refractive error
◦ Force the poorer eye by limiting use of
the better eye
4. Full time vs Part time occlusion
google.images for amblyopia therapy
5. Gold std for amblyopia Tx
Adhesives work best
Costly
Some skin irritation
Alternative use- felt patch
Easier to peak in non
adhesive patch
Always use specs if
google.images significant Rx
Occasionally covered by
insurance
Use of splints and restraints?
6. Why isn’t patching successful?
Compliance?
How to enhance compliance?
Why are children not
compliant?
social stigma
skin irritation
just don’t like it
sensory abnormality
Awan et al report compliance
rates of 58 and 41% when
patching rx for 3hr or 6hr.
google.images
7. Used daily to weekly
Better with hyperopes
Nearly ineffective in
myopic children
Blurs to about 20/120
Often tolerated better
than patching
Works best to remove
any plus in glasses
google.images
8. Penalization Pearls
•Best used for those with patching
failure
•Hyperopes
•Old enough to watch sound eye
vistakon
•Maybe less regression when stopping
treatment
9. Reduce or eliminate
necessary refractive
power to blur the
sound eye
Mostly used in
hyperopia
Works synergistically
with atropine
Very effective in high
ametropia
10. Occlusive contact
lens
Often used as final
means of treatment
Costly, risks of
infection to sound
eye, easy to rub out
Able to custom make
any base curve or
diameter
google.images
11. Bangerter filter
◦ Degrades image
May allow child
binocularity
Improved tolerance
over complete
occlusion
Unfortunately, many
look over specs in liu
of using specs
coopereyecare
12. Part time occlusion is labor
intensive
Constant monitoring is
sometimes required
Two parents working; who is
monitoring PTO compliance?
Refractive surgery may benefit
children with spectacle non-
compliance
Currently WUSM is one of only a
few centers in North America
offering pediatic refractive
surgery for amblyopia
13. In office and home
based therapy
Utilized for
improvements of
amblyopia
Met with some
debate yet merits
14. Few pediatric specialists in North America offer this
treatment in children
Multiple challenges include fixation, discomfort, long term
changes, testing, compliance
Able to treat refractive error in children intolerant to
glasses and contact lenses
Neurobehavioral abnormalities create increased challenges
15. 14 month old with
eye misaligment X4 -
6 mos
Left eye goes to the
nose
FFM OD FFU OS
30 LET
Cycloplegic refraction
reveals
+3.50 OD and +5.00
OS
volunteer model
16. You have access to
Spatial Sweep
VEP, Flash
VEP, Pattern
VEP,Multifocal
ERG,Traditional ERG
Cardiff, OKN, Plus
Optix, EOG, OKN
recording, OKN
tracing, HRT and google.images
Pupillography
recording
Follow Up? Treatment
?
17. Full cycloplegic RX
6 week follow up
PTO 50% of
waking hours
Spec wear
recommend full
time (>80%)
+3.50 OD and
+5.00 OS
18. Wears specs fairly
well
Patching 5 hours per
day
10 PD LET
Tx option now?
19. Wears specs fairly
well
Patching 5 hours per
day
10 PD LET
Tx option now?
Reduce PTO to 2 hrs
day and follow up 3
months
20. FFM OD and OS
NO Longer
crossing
Patching 3 hrs a
day
Clinical Follow up
demonstrates
good alignment
and tracking
Washington University School of
Medicine and Barnes Jewish
Hospital
21. So D/C PTO and
order SSVEP
(is VA better with
grating charts
than letter charts?)
google.images for amblyopia
therapy
22. SSVEP reveals 20/50 and 20/85
Regression noted
Treated with 2 hours a day PTO and 4
month follow up
23. 20/20 and
20/25++
9/9 circles
(Titmus)
Wears+2.50,+3.7
5
Still esotropic sin
Rx
24. Patch 2 hrs a day or Atropine
Not
Resolved
Improved Not Improved Switch
Treatment
Amblyopia Good
Resolved Compliance Poor
Compliance
Increase
INTENSITY
+/- Taper
then D/C
Not Improved
(residual
amblyopia) Consider
Not Improved final push
25. Spectacles are widely accepted form of
amblyopia treatment
Visual acuity improves in some amblyopic
children
This improvement in vision is now referred
to as refractive adaptation; PEDIG refers to
this as ‘optical treatment’
Most ECP Rx glasses then follow up VA after
few months of spec wear (PEDIG 18 weeks)
google.images for amblyopia
therapy
26. 7y/o wm referred
because he often
closes one eye
UCVA 20/20 and
20/160
+fly and orthophoria
(no refractive ET)
Cycloplegic refraction
is +1.00 and +6.00 -
0.75 X 063 20/160++
Tx options: ?????
Patients evidence of patching
27. Specs rx -1D over
cyclo
PTO: 2 hours OD
4 month f/u VA
◦ 20/50+
◦ Continue as previous
◦ 4 mo later 20/40+
◦ 4 mo later 20/30-
◦ 4 mo later 20/30+
◦ Pt cuts PTO 20/40+2
Happily shows his work!
29. Eligibility
Age 10 to <18 years
Amblyopic eye acuity of 20/40 to 20/160
Treatment
>2 hours daily patching
At least one hour of near activities during
patching
Outcome: Visual acuity after two months of
treatment
Results: Visual acuity improved >2 lines in 18
(27%)
of 66 patients
30. PEDIG ATS studies
include:
6 hours vs full
time for severe
(20/100 to
20/400)
Or in older
children 2 to 6
hours per day
+Atropine + near
google.images for amblyopia
therapy
31. CLs are well tolerated in anisometropia
More equal retinal image sizes
Improved binocularity and stereopsis
Improved compliance if sound eye has refractive
error
32. Infants with high amounts of
anisometropia require contact lenses to
reduce risk of dense amblyopia
CJ Roberts study shows successful use of
CL for 6 diopters of myopic aniso
improved 3-4 lines. Not as successful in
>10 diopters of anisometropia.
Improvement in VA w/in 6 months
33. Occasionally sound eye is reduced
Mostly at risk if child is very young
Skin irritation is typically temporary
Cholinergic side effects of A1%
Hypothetical increase in UV rays (A1%)
Decreased academics (?) due to reading
dysfunction or struggles associated with
reading through amblyopic eye
34. PEDIG ATS 3
◦ Children 7-18 yo
◦ Optical correction alone
◦ Optical correction plus patching
◦ And Daily A1% <12 yo
◦ 53% improved at least 2 lines
◦ 47% of 13-17 yo improved if no
prior tx
35. Isoametropia Diopters
◦ Astigmatism >2.50 D
◦ Hyperopia >5.00 D
◦ Myopia >8.00 D
Anisometropia
◦ Astigmatism >1.50 D
◦ Hyperopia >1.00 D
◦ Myopia >3.00 D
google.images for amblyopia
therapy
36. Animals with early onset
amblyopia have
predominately
monocular connections
Cytochrome oxidase
highlights metabolic
activity in ocular
dominance columns
which is reduced in
amblyopia
google.images for amblyopia
therapy
37. Mosaic of ocular
dominance columns
in striate cortex
revealed by
processing the tissue
for cytochrome
oxidase in a patient
who lost sight in one
eye prior to his death
Jonathan horton’s lab pub at ucsf
38. Many children left with 20/30 or worse
Regression is common in >40% of amblyopic
treatments
Prescribe Polycarbonate lenses
Caution with soft contact lenses
◦ Especially extended wear
39. Probably two-thirds of
amblyopes are purely
refractive and probably one
third are associated with
microtropia
Microtropia likely results in
poorer vision at the time of
presentation
Does anisometropia create
loss of bifoveal fixation or
does loss of foveal fixation
cause the secondary
amblyopia?
40. Factors thought to affect treatment outcomes
◦ Compliance: significant role in outcome
◦ Age at commencement of treatment
◦ Density of the amblyopia
Severity of vision loss at time of presentation
Specs or CLs and 2-3 hours of daily patching
should solve a great deal of amblyopic needs
If specs or contact lenses fail then consider
non traditional treatments
google.images for amblyopia
therapy
41. Horton, J. Stryker, M. Amblyopia induced by anisometropia without shrinkage of
ocular dominance columns in human striate cortex. Proc. Natl. Acad. Sci. USA Vol.
90. p. 594-5498, June 1993 Neurobiology
Braverman, R. Diagnosis and treatment of refractive errors in the pediatric
population. Current Opinion in Ophthalmology Vol 18 (5) September 2007. 379-
383.
Steinman, S. Steinman, B. Garzia, R. Foundations of Binocular Vision: A Clinical
Perspective. 2000 McGraw Hill Publishing
Pediatric Eye Disease Investigational Group (2005) Randomized trial of treatment of
amblyopia in children aged 7-17 years. Arch Ophthalmol 123: 437-447.
Donahue, S. The Relationship between anisometropia, patient, age, and the
development of amblyopia. Trans Am Ophthalmol Soc 2005; 103:313-336.
Pediatric Eye Disease Investigator Group. A randomized trial of patching regimens
for treatment of severe amblyopia in children. Ophthalmology 2003; 110:2075-
87.
Pediatric Eye Disease Investigator Group. Randomized trial of treatment of
amblyopia in children aged 7 to 17 years. Arch Ophthalmol 2005; 123:437-47.
Sakatani, K. Jabbur, N. O’Brien, T. Improvement in best corrected visual acuity in
amblyopic adult eyes after laser in situ keratomileusis. J Cataract Refract Surg
2004; 30:2517-2521.
42. Wallace, D. ( 2009)Pediatric Ophthalmology: Current
Thought and a Practical Guide. Springer. M. Edward
Wilson ed. Pp33-46.
Awan M, Proudlock FA, Gottlob I (2005) A
randomized controlled trial of unilateral strabismic
and mixed amblyopia using occlusion dose monitors
to record compliance. Invest Ophthal Vis Sci 46:
1435-1439.
Editor's Notes
Oto et al reported non compliance rate of 47% with patching programs
Inconspicuous in some children and frighteningly obvious in others.Generally well tolerated
In our office this language translates as discontinue part time occlusion and order spatial sweep visual evoked potential. Some believe due to motor control component, gratings are redundant and so make less demands on gaze control. Some severe amblyopes like those of congenital cataracts may have a difficult time holding steady vision
Pattern of ocular dominance columns along the medial face of the right human occipital lobe. The dashed line
Figure 20: Mosaic of ocular dominance columns in striate cortex revealed by processing the tissue for cytochromeoxidase in a patient who lost sight in one eye prior to his death. The image above shows the actual tissue montage; the image below is a sketch of the columns. Note the partial reconstruction of dark and pale cytochromeoxidase stripes in V2. BS = blind spot; MC = monocular crescent.We have examined the ocular dominance columns in a patient with strabismic amblyopia and in a patient with anisometropic amblyopia (see: Horton JC & Stryker MP, Anisometropia induces amblyopia without shrinkage of ocular dominance columns in human striate cortex. Proc. Natl Acad. Sci, 90:5494-5498, 1993 and Horton JC & Hocking DR, Pattern of ocular dominance columns in human striate cortex in strabismic amblyopia. Visual Neuroscience, 13:787-795, 1996). Neither case showed evidence of shrinkage of the amblyopic eye’s ocular dominance columns. From these findings, we conclude that amblyopia is not always associated with reduction in the size of ocular dominance columns. It is possible that when amblyopia begins at a later age it is not accompanied by a change in the dimensions of ocular dominance columns. Presumably abnormalities in intracortical wiring, yet to be revealed, are responsible for amblyopia in these cases.From our studies, it is apparent that many anatomical features of the macaque visual cortex are also present in the human visual cortex. Their similarity gives us confidence that our research findings in the macaque are applicable to the human. This is gratifying, because our ultimate goal is to understand how the human visual system functions. Continuing studies in the macaque, therefore, will allow us to make further advances in understanding the human visual system. In turn, human studies will continue to help shape our experiments in the macaque.