week eye

1. AMBLYOPIA
S. Arya das
3rd year, B.Optom.
B.M.C.O

2. DEFINITION
it is unilateral or bilateral decrease of best
corrected visual acuity caused by form
vision deprivation and/or abnormal
binocular interaction for which there is no
obvious visual pathway pathology.

3. DEFINITION
Ambloypia in simple means
dullness of vision or diminished
vision.
It arises from a Greek word.
ambly=dull+ ops=vision
 It can be unilateral or bilateral.

4. ETIOLOGY
Occlusion, strabismus,
anisometropia, uncorrected high
refractive errors.
Opacities of ocular media.
Deprivation of light or form
sense.

5. CLASSIFICATION
Functional amblyopia- which is
reversible.
Organic amblyopia- which is not
reversible.

6. FUNCTIONAL AMBLYOPIA
It is sub classified as :-
Strabismus amblyopia.
Refractive amblyopia.
Anisometropic amblyopia.
Ammetrpoic amblyopia.
Meridonial amblyopia.

7. FUNCTIONAL AMBLYOPIA
Stimulus deprivation amblyopia
Idiopathic amblyopia
Amblyopia secondary to
Nystagmus
Hysterical amblyiopia

8. STABISMIC AMBLYOPIA
Active cortical inhibition point is zero
in deviating eye.
Stereopsis is severely decreased or
absent.
Visual acuity loss is more compared
to anisometropic amblyopia.

9. STABISMIC AMBLYOPIA
Patients with strabismus who strongly use
only one eye for fixation are most likely to
acquire strabismus amblyopia.
Amblyopia is found more in esotropes than
in exotropes, because in esotropes it is
related to nasotemporal asymmetry.

10.  In esotropia fovea of the deviated eye has to
compete with the strong temporal hemi field of
the good eye, whereas in exotropia fovea has to
compete with the weaker nasal hemi field.
 Etiology of starbismic amblyopia is similar to that
of suppression, but supp is restricted to
binocular vision where monocular visual acuity
may be normal thus amblyopia may be
considered a carryover of suppression in
monocular vision and may called as
suppression.

11. REFRACTIVE AMBLYOPIA
ANISOMETROPIC AMBLYOPIA
It is because of unequal refractive error in two
eye.
 Strabismus is often associated with anisometropia. In
strabismic amblyopia there is an active inhibition where
as in anisometropic amblyopia the purpose of inhibition is
to eliminate sensory interference caused by
superimposition of a focused and a defocused image
originating from the fixation point.

12.  Binocular v/a in anisometropic eye is lower then
measured monocularly. overall contrast
sensitivity is also reduced.
 Amblyopia I s more common in patients with
anisohypermetropia than in anisomyopia.
 The retina of more ammetropic eye of a pair of
hypermetropic eye never receives a clearly
defined image since with details clearly focused
on the fovea of the better eye, no strabis

13. REFRACTIVE AMBLYOPIA
AMMETROPIC AMBLYOPIA
Due to uncorrected high refractive
error.
Bilateral amblyopia.
Isoametropic amblyopia can be
classified under this. Occurs in children
havin More than +5.00D or More -
10.00D.

14. REFRACTIVE AMBLYOPIA
MERIDONIAL AMBLYOPIA
Occurs due to uncorrected
astigmatic refractive error.

15. STIMULUS DEPRIVIATION
AMBLYOPIA
Result of lack of adequate visual
stimulus in early life.
Can be unilateral or bilateral.
Can be complete (when no light
entering) or Partial (when some
light enters).

16. AMBLYOPIA EXAMOPSIA
Due to disuse of the eyes.
E.g. Uniocular, congenital, or
traumatic cataract, corneal
opacity, complete ptosis occlusion
amblyopia.

17. IDIOPATHIC AMBLYOPIA
Unilateral.
Occurs in normal patients.
-Ve history of strabismus.
Clinically V/A and foveal suppression
will improve after patching the good
eye.
But it will recur once the treatment is
stopped.

18. AMBLYOPIA SECONDARY TO
NYSTAGMUS
Bilateral.
Secondary due to nystagmus.
Difficult to assess.

19. HYSTERICAL AMBLYOPIA
It is the form of psychoneurosis.
Common in females.

20. ORGANIC AMBLYOPIA
Irreversible.
Due to undetectable organic lesion in
the visual pathway.
Classified as Toxic amblyopia.
Visual loss results from damage to
optic nerve fibers.
Due to certain poisons such such as
tobacco, ethyl, alcohol,
chloroquimine.

21. PATHOPHYSIOLOGY OF
AMBLYOPIA.
1. Amblyopic Factor-
1. Visual Depriviation.
2. Light depriviation.
3. Abnormal binocular interaction.

22. CHARACTERISTICS OF
AMBLYOPIC PATIENT
 Reduced vision.
 Decreased contrast sensitivity.
 Suppression.
 Decreased stereopsis.
 Defective accommodation,
convergence and fusional vergence
affected.

23. CHARACTERISTICS OF
AMBLYOPIC PATIENT
 Spatial uncertainty (hand and
eye coordination not good).
 Crowding phenomena-
 May have unsteady fixation.
 May be associated with squint.

24. INVESTIGATIONS
 History.
 Visual acuity.
 Refraction.
 Cover test.
 Ocular motility.

25. INVESTIGATIONS
 Binocular assesment.
 Fixation pattern.
 Neutral density filter.

26. FIXATION PATTERN
 Can be centric i.e. with fovea.
 Can be eccentric i.e. any other
point except fovea.

27. CLASSIFICATION OF FIXATION
PATTERN
 Foveal fixation with 2 degrees of
fovea.
 Parafoveal fixation with 2-5 degrees
of fovea.
 Para macular 5-10 degrees.
 More than 10 degrees i.e. peripheral
fixation.

28. TREATMENT OF AMBLYOPIA
 OCCLUSION
 PENALISATION
 PLEOPTICS
 CAM VISION STIMULATION
 RED FILTER TREATMENT
 MEDICAL TREATMENT
 ACTIVE VISION THERAPY

29. TYPES OF OCCLUSION
A] TOTAL OCCLUSION
It is mainly use for moderate to severe
amblyopia.
Different forms:
1. Direct skin patch
2. spectacle patch
3. doyne’s occluders
4. contact lenses

30. B] partial occlusion:
It depends upon bases of duration or
period of occlusion
1. full time occlusion
2. part time occlusion

31. Penalization
Types of penalization
 Optical penalization
 Pharmacological
 Partial occlusion
Pleoptics
 pleos = full, & optics= sight.
 VISUSCOPE & EUTHYSCOPE is use for 20 to 30
seconds.

32. Red filter treatment
The filter is use named KODAK GELATIN
WRATTEN FILTER NO. 92.
It’S IS USED VERY RARELY…