NAVP Treatment of Amblyopia
By James Hoekel OD FAAOSt. Louis Children’s Hospital Eye Center
Washington University School of Medicine
None
Financial Disclosures
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
google.images for amblyopia therapy
Full time vs Part time occlusion
Eye Occlusors
Gold std for amblyopia Tx Adhesives work best
CostlySome skin irritationAlternative use- felt patchEasier to peak in non
adhesive patchAlways use specs if
significant RxOccasionally covered by
insuranceUse of splints and restraints?
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Patching as a Treatment Option
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.
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Atropine 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
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Penalization Pearls
•Best used for those with patching failure
•Hyperopes
•Old enough to watch sound eye
•Maybe less regression when stopping treatment
vistakon
Optical Penalization
Reduce or eliminate necessary refractive power to blur the sound eye
Mostly used in hyperopia
Works synergistically with atropine
Very effective in high ametropia
Non Traditional Occlusion
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
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Bangerter filter◦ Degrades image
May allow child binocularity
Improved tolerance over complete occlusion
Unfortunately, many look over specs in liu of using specs
coopereyecare
Traditional and Non-Traditional Treatment of Amblyopia
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
Vision Therapy In office and home
based therapy Utilized for
improvements of amblyopia
Met with some debate yet merits
PRK for Anisometropia
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
Case Report #1
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
You make the call
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 Pupillography recording
Follow Up? Treatment ?
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Case Report #1
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
Follow up (6 weeks) Wears specs fairly
well Patching 5 hours per
day 10 PD LET Tx option now?
Follow up (6 weeks) 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
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
So D/C PTO and order SSVEP
(is VA better with grating charts than letter charts?)
google.images for amblyopia therapy
Follow up visit 4
SSVEP reveals 20/50 and 20/85 Regression noted Treated with 2 hours a day PTO and 4
month follow up
Follow up (7 yrs later)
20/20 and 20/25+
+
9/9 circles (Titmus)
Wears+2.50,+3.75
Still esotropic sin Rx
Patch 2 hrs a day or Atropine
Switch Treatment
Not Resolved
Poor Compliance
Not ImprovedImproved
Good Complianc
e
Amblyopia Resolved
Not Improved (residual
amblyopia)
+/- Taper then D/C
Not Improved
Increase INTENSITY
Consider final push
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)
Spectacles for Anisometropic Amblyopia
google.images for amblyopia therapy
Case Report #2
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
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!
An Evaluation of Treatment of Amblyopia in Children 7-<18 Years Old
Supported by the National Eye Institute
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
PEDIG Pilot Study
Learning points
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
Contact Lenses for Anisometropia
CLs are well tolerated in anisometropia More equal retinal image sizes Improved binocularity and stereopsis Improved compliance if sound eye has
refractive error
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
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
Risks or Complications of Anisometropic Amblyopic Treatment
How Old is Too Old to Treat Amblyopia? 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
Isoametropia Diopters◦ Astigmatism >2.50 D◦ Hyperopia >5.00 D◦ Myopia >8.00 DAnisometropia◦ Astigmatism >1.50 D◦ Hyperopia >1.00 D◦ Myopia >3.00 D
AOA Clinical Practice Guideline on Amblyopia
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Amblyopia Research
Animals with early onset amblyopia have predominately monocular connections
Cytochrome oxidase highlights metabolic activity in ocular dominance columns which is reduced in amblyopia
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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
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
Residual Amblyopia
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?
Take Home Points
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
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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.
References
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.