NAVP Treatment of Amblyopia

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

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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?)

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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

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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

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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.