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SAFII RAHMI SAFII RAHMI

R. HANDOKO PRATOMOR. HANDOKO PRATOMO

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Unilateral or less commonly, bilateral Unilateral or less commonly, bilateral reduction of best corrected visual acuity that reduction of best corrected visual acuity that can not be attributed directly to the effect of can not be attributed directly to the effect of any structural abnormality of the eye or the any structural abnormality of the eye or the posterior visual pathway. Defect of central posterior visual pathway. Defect of central vision vision

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Resulting from one of following: Resulting from one of following:

A.A. StrabismusStrabismusB.B. Anisometropia or high bilateral refractive Anisometropia or high bilateral refractive

error (Isoametropia) error (Isoametropia) C.C. Visual deprivation Visual deprivation

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Prevalence: 2%-4% in the North American Prevalence: 2%-4% in the North American population population

Commonly unilateral Commonly unilateral Nearly all amblyopic visual loss is Nearly all amblyopic visual loss is

preventable or reversible with timely preventable or reversible with timely detection and appropriate intervention.detection and appropriate intervention.

Children with amblyopia or at risk for Children with amblyopia or at risk for amblyopia should be identified at a young amblyopia should be identified at a young age when the prognosis for successful age when the prognosis for successful treatment is best. treatment is best.

Role of screening is important Role of screening is important

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Amblyopia is primarily a defect of central Amblyopia is primarily a defect of central vision. vision.

There is a critical period for sensitivity in There is a critical period for sensitivity in developing amblyopia.developing amblyopia.

The time necessary for amblyopia to occur The time necessary for amblyopia to occur during critical period is shorter for stimulus during critical period is shorter for stimulus deprivation than for strabismus or deprivation than for strabismus or anisometropia.anisometropia.

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Neurophysiology:Neurophysiology:

Cells of the primary visual cortex can completely Cells of the primary visual cortex can completely lose their innate ability or show significant lose their innate ability or show significant functional functional deficiencies deficiencies

Abnormalities also occur in neurons in the lateral Abnormalities also occur in neurons in the lateral geniculate body geniculate body

Evidence concerning involvement at the retinal level Evidence concerning involvement at the retinal level remains inconclusive remains inconclusive

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Classification:Classification:

1.1. Strabismus Amblyopia Strabismus Amblyopia 2.2. Anisometropia AmblyopiaAnisometropia Amblyopia3.3. Amblyopia Due to bilateral high refractive Amblyopia Due to bilateral high refractive

error (isometropia)error (isometropia)4.4. Deprivation AmblyopiaDeprivation Amblyopia

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Strabismus AmblyopiaStrabismus Amblyopia

The most common form of amblyopiaThe most common form of amblyopia Strabismic amblyopia is thought to result Strabismic amblyopia is thought to result

from competitive or inhibitory interaction from competitive or inhibitory interaction between neurons carrying the nonfusible between neurons carrying the nonfusible inputs from the tow eye.inputs from the tow eye.

Which leads to domination of cortical vision Which leads to domination of cortical vision centers by the fixating eye and chronically centers by the fixating eye and chronically reduced responsiveness to the nonfixating reduced responsiveness to the nonfixating eye input. eye input.

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Anisometropia AmblyopiaAnisometropia Amblyopia

Second in frequency Second in frequency It develops when unequal refractive error in the tow It develops when unequal refractive error in the tow

eyes causes the image on the one retina to be eyes causes the image on the one retina to be chronically defocused.chronically defocused.

This condition is thought to result:This condition is thought to result: Partly from the direct effect of image blur in the Partly from the direct effect of image blur in the

development of visual acuity.development of visual acuity. Partly from intraocular competition or inhibitionPartly from intraocular competition or inhibition

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Mild hyperopic or astigmatic anisometropia Mild hyperopic or astigmatic anisometropia (1-2D) (1-2D) mild amblyopia mild amblyopia

Mild myopia anisometropia (less than -3D) Mild myopia anisometropia (less than -3D) usually doesn't cause amblyopiausually doesn't cause amblyopia

unilateral high myopia (-6D) unilateral high myopia (-6D) sever sever amblyopia visual loss.amblyopia visual loss.

The eye s of a child with anisometropic The eye s of a child with anisometropic amblyopia look normaly to the family and amblyopia look normaly to the family and primary care physician. primary care physician.

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Amblyopia Due to bilateral high Amblyopia Due to bilateral high refractive error (isometropia)refractive error (isometropia)

isometropia amblyopia result from large, isometropia amblyopia result from large, approximately equal, uncorrected refractive approximately equal, uncorrected refractive error in both eyes of a young child.error in both eyes of a young child.

Hyperopia exceeding 5D & myopia excess of Hyperopia exceeding 5D & myopia excess of 10 D 10 D risk risk bilateral amblyopia bilateral amblyopia

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Merdional amblyopia:Merdional amblyopia: Uncorrected bilateral astigmatism in early Uncorrected bilateral astigmatism in early

childhood may result in loss of resoling childhood may result in loss of resoling ability limited to chronically blurred ability limited to chronically blurred meridians.meridians.

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Deprivation AmblyopiaDeprivation Amblyopia

It is usually caused by congenital or early It is usually caused by congenital or early acquired media opacity.acquired media opacity.

This form of amblyopia is the least common This form of amblyopia is the least common but most damaging and difficult to treat. but most damaging and difficult to treat.

In bilateral cases acuity can be 20/200 or In bilateral cases acuity can be 20/200 or worse.worse.

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In children younger than 6 years, dons In children younger than 6 years, dons congenital cataract that occupy the central 3 congenital cataract that occupy the central 3 mm. or more of the lens must be considered mm. or more of the lens must be considered capable of causing sever amblyopiacapable of causing sever amblyopia..

Similar lens opacities acquired after 6 years Similar lens opacities acquired after 6 years are generally less harmful.are generally less harmful.

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Small polar cataracts & lamellar cataracts Small polar cataracts & lamellar cataracts may cause mild to moderate amblyopia or may cause mild to moderate amblyopia or may have no effect on visual development.may have no effect on visual development.

Occlusion amblyopia is a form of deprivation Occlusion amblyopia is a form of deprivation caused by excessive therapeutic patching. caused by excessive therapeutic patching.

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Diagnosis Diagnosis

Characteristics of vision alone cannot be Characteristics of vision alone cannot be used to reliably differentiated amblyopia from used to reliably differentiated amblyopia from other form of visual loss. other form of visual loss.

The crowding phenomenon is typical for The crowding phenomenon is typical for amblyopia but not uniformly demonstrable.amblyopia but not uniformly demonstrable.

Afferent pupillary defect are Characteristic of Afferent pupillary defect are Characteristic of optic nerve disease but occasiinally appear to optic nerve disease but occasiinally appear to be present with amblyopia be present with amblyopia

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Multiple assessment using a variety of tests or Multiple assessment using a variety of tests or performed on different occasions are performed on different occasions are sometime required to make a final judgment sometime required to make a final judgment concerning the presence and severity of concerning the presence and severity of amblyopia.amblyopia.

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Binocular fixation pattern:Binocular fixation pattern: It is a test for estimating the relative level of It is a test for estimating the relative level of

vision in the tow eyes for children with vision in the tow eyes for children with strabismus who are under the age of about 3.strabismus who are under the age of about 3.

This test is quite sensitive for detecting This test is quite sensitive for detecting amblyopia but results can be falsely positive.amblyopia but results can be falsely positive.

Showing a strong preference when sision is Showing a strong preference when sision is equal or nearly equal in the tow eyes, equal or nearly equal in the tow eyes, particularly with small angle strabismic particularly with small angle strabismic deviations.deviations.

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The modified Snellen technique directly The modified Snellen technique directly measures acuity in children 3-6 years old.measures acuity in children 3-6 years old.

Often, however, only isolated letters can be Often, however, only isolated letters can be used, which may lead to under estimated used, which may lead to under estimated amblyopia visual loss.amblyopia visual loss.

Croding bar may help alleviate this problem.Croding bar may help alleviate this problem.

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Crowding bar, or contour interaction bars, allow the Crowding bar, or contour interaction bars, allow the examinator to test the crowing phenomenon with examinator to test the crowing phenomenon with isolated optotype. Bar surrounding the optotype isolated optotype. Bar surrounding the optotype mimic the full of optotype to the amblyopia child.mimic the full of optotype to the amblyopia child.

E O

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Treatment Treatment

Treatment of amblyopiaTreatment of amblyopia involves the involves the following steps: following steps:

Eliminating (if possible) any obstacle to Eliminating (if possible) any obstacle to vision such as a cataract vision such as a cataract

Correcting refractive error Correcting refractive error Forcing use of the poorer eye by limiting use Forcing use of the poorer eye by limiting use

of the better eye.of the better eye.

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Cataract removal Cataract removal Cataracts capable of producing amblyopia require Cataracts capable of producing amblyopia require

surgery without unnecessary delay.surgery without unnecessary delay. Removal of significant congenital lens opacities Removal of significant congenital lens opacities

during the first 2-3 months of life is necessary for during the first 2-3 months of life is necessary for optimal recovery of vision.optimal recovery of vision.

In symmetrical bilateral cases, the interval between In symmetrical bilateral cases, the interval between operations on the first and second eyes should be no operations on the first and second eyes should be no more than 1-2 weeks.more than 1-2 weeks.

Acutely developing severe traumatic cataracts in Acutely developing severe traumatic cataracts in children younger than 6 years should be removed children younger than 6 years should be removed within a few weeks of injury, if possible.within a few weeks of injury, if possible.

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Refractive correction Refractive correction

In generally, optical prescription for In generally, optical prescription for amblyopic eyes should correct the full amblyopic eyes should correct the full refractive error as determined with refractive error as determined with cyclopagic.cyclopagic.

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Occlusion and optical degradation Occlusion and optical degradation Full time occlusion of the sound eye:Full time occlusion of the sound eye: Defined as occlusion for all or all but one waking Defined as occlusion for all or all but one waking

hour. hour. It is the most powerful means of treating of It is the most powerful means of treating of

amblyopia by enforced use of the defective eye. amblyopia by enforced use of the defective eye. The patch can either be left in place at night or The patch can either be left in place at night or

removed at bedtime.removed at bedtime. Spectacle-mounted occluser or special opaque Spectacle-mounted occluser or special opaque

contact lenses can be used as an alternative to full-contact lenses can be used as an alternative to full-time patching if skin irritation or poor adhesion time patching if skin irritation or poor adhesion proves to be a significant problemproves to be a significant problem

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Full time patching should generally be used Full time patching should generally be used only when constant strabismus eliminates only when constant strabismus eliminates any possibility of useful binocular vision any possibility of useful binocular vision because because full time patching runs a small full time patching runs a small risk of perturbing binocularity. risk of perturbing binocularity.

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Part-time occlusion:Part-time occlusion: Defined as occlusion for 1-6 hours per day.Defined as occlusion for 1-6 hours per day. The children undergoing part time occlusion The children undergoing part time occlusion

should be kept as visually active as possible should be kept as visually active as possible when the patch is in place.when the patch is in place.

Compliance with occlusion therapy for Compliance with occlusion therapy for amblyopia declines with increasing age.amblyopia declines with increasing age.

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Penalization: Penalization: A cyclopagic agent (usually atropine 1% or A cyclopagic agent (usually atropine 1% or

homatropine 5% )homatropine 5% ) once daily to the better once daily to the better eye eye

This form of treatment has recently been This form of treatment has recently been demonstrated to be as effective as patching demonstrated to be as effective as patching for mild to moderate amblyopia. for mild to moderate amblyopia.

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Complication of therapy Complication of therapy Full time occlusion carries the greatest risk of this Full time occlusion carries the greatest risk of this

complication and requires close monitoring, complication and requires close monitoring, especially in the younger child.especially in the younger child.

The first follow up visit after initial treatment The first follow up visit after initial treatment should occur within 1 week for an infant and after should occur within 1 week for an infant and after interval corresponding to 1 week per year of age for interval corresponding to 1 week per year of age for the older child.the older child.

Part time occlusion & optical degradation methods Part time occlusion & optical degradation methods allow for less frequent observation but regular allow for less frequent observation but regular follow up is still critical follow up is still critical

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The time required for completion of The time required for completion of treatment depends on the following: treatment depends on the following:

1.1. Degree of amblyopia Degree of amblyopia 2.2. Choice of therapeutic approach Choice of therapeutic approach 3.3. Compliance with the prescribed regimen Compliance with the prescribed regimen 4.4. age of the patient age of the patient

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Unresponsiveness Unresponsiveness Complete or partial Unresponsiveness to treatment Complete or partial Unresponsiveness to treatment

occasionally affect younger children but must often occasionally affect younger children but must often occurs in patients older than 5 years.occurs in patients older than 5 years.

Primary therapy should generally be terminated if Primary therapy should generally be terminated if there is a lock of demonstrable progress over 3-6 there is a lock of demonstrable progress over 3-6 months with good compliance.months with good compliance.

Refraction should be carefully rechecked and the Refraction should be carefully rechecked and the macula and optic nerve critically inspected for macula and optic nerve critically inspected for subtle evidence of hypoplasia or other malformation subtle evidence of hypoplasia or other malformation that might have been previously overlooked. that might have been previously overlooked.

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Recurrence Recurrence

When amblyopia treatment is discontinued after fully When amblyopia treatment is discontinued after fully or partially successful completion, approximately half or partially successful completion, approximately half of patients show some dgree of recurrence,of patients show some dgree of recurrence,

Maintenance therapy: Maintenance therapy: Patching for 1-3 hours per day Patching for 1-3 hours per day Optical penalization with spectacles Optical penalization with spectacles Pharmacologic penalization with atropine 1 or 2 day Pharmacologic penalization with atropine 1 or 2 day

per week.per week. This may require periodic monitoring until age 8-10. This may require periodic monitoring until age 8-10.

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