Amblyopia

1. AMBLYOPIA
-SHAHZADI SHADHULI

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DEFINITION
Amblyopia is a partial loss of sight in one or both
eyes.
It is a uniocular impairment of vision in the
absence of any organic disease of ocular media
and visual pathway

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CLASSIFICATION
STRABISMIC AMBLYOPIA
REFRACTIVE AMBLYOPIA
*ANISOMETROPIC AMBLYOPIA
*BILATERAL AMBLYOPIA
*MERIDIONAL AMBLYOPIA
STIMULUS DEPRIVATION AMBLYOPIA

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STRABISMIC AMBLYOPIA
It occurs because of squint in one eye- the squinting eye has less
vision.
Typical Features :
Always unilateral
More often in esotropes than exotropes
Very rare in hypertropia

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2. REFRACTIVE AMBLYOPIA
This is due to uncorrected refractive error.
This may be on the following types:
Anisometropic Amblyopia
It develops due to difference in refractive error between the two eyes.
This leads to amblyopia in the eye with the larger refractive error, if
corrective glasses are not worn.
Hypermetropes are more prone to develop Anisometropic amblyopia.

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Bilateral Amblyopia
Bilateral Ametropic Amblyopic can occur if the refractive error is high
in both eyes and is not corrected.
Meridional Amblyopia
Meridional Amblyopia is the term used when amblyopia affects only
one meridian due to high astigmatic error.

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3. STIMULUS DEPRIVATION AMBLYOPIA
It is seen in cases having media opacity in the form of cataract or
corneal opacity from early childhood.
These children develop amblyopia due to visual form deprivation.
CLINICAL FEATURES
Unilateral or bilateral reduced vision
Crowding phenomenon may be seen: The patient is able to identify
a snellen chart character with the amblyopic eye when the
character is presented in isolation. If the character is shown

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Along with other letters, the patient may not be able to recognize it.
Neutral identity filter test(NDF): when the patient is asked to read
through a NDF, the amblyopic eye shows no change, while in the
normal eye, there is a drop in visual acuity.
Development of macula continues till 6 years of age. During this
developmental phase any obstruction to vision or any lack of
coordination between 2 eyes may cause amblyopia.
Sometimes children cannot know that there is less vision in one eye
- as a result amblyopia is not detected on time.
TREATMENT
Treament of cataract , corneal opacity, etc. are to be done.

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Occlusion therapy
Occlusion of good eye, and allowing to use the amblyopic eye.
Penalization
If child is not co-operative to occlusion, penalization by instillation of
atropine in the good eye is the next option.