amblyopia opthalmology for mbbs students

1. By AMEERHAMZA S B
6th term MBBS
Shimoga Institute of Medical Sciences
Shimoga

2.  We learn to see, like walking or talking
 Learning to see is a slow process
 At birth – vision is noisy, can not distinguish targets
 Object tracking starts around 3 month old
 Hand-eye-body coordination starts after 3 month old
 Depth perception appears after 5 month old
 Vision is well developed by two years old

3. It refers to a partial reversible
loss of vision in one or both eyes, for
which no cause can be found by physical
examination of eye(absence of any
organic disease).

4. Amblyopia is an eye condition when the
nerves that connect one of the eyes to the brain do
not develop correctly during childhood. As a
result, the person sends blurry or wrong images to
their brain, which results in the brain ignoring the
information and favoring the other eye. Patients
are seen using one eye more or may have problems
with depth perception.

6.  Two eye moves in two
direction
 Brain cannot combine image
from two eye into one
 Double vision
 Brain starts to ignore image
from one eye
 Causes unilateral amblyopia

7.  Congenital or traumatic
cataract or corneal haziness
 Occlude lights to reach the
retina
 No or distorted image
formed on retina
 No visual learning happens
 Both unilateral or bilateral
amblyopia can occur

8.  Different focusing power in
two eye
 One eye gives clearer
image than other
 Brain starts to ignore the
blurrier image
 Causes unilateral
amblyopia

9.  Is bilateral amblyopia occuring in children
with bilateral uncorrected high refractive
error
 Occurs in children eith uncorrected
astigmatic refractive error
Meridional amblyoipa

10.  Visual acuity is decreased
 Crowding phenomenon : visual acuity is less
when tested with multiple letter charts
(eg.snellen’s chart)than single letter charts
(eg.optotype).

11.  Younger the child , better is the prognosis.
 Works best when child is under 3yrs of age.
1) Occlusion therapy : occlusion normal eye
to force use of amblyopic eye

12. Before that procedure it should be ensured that
 If any cataract…. is corrected.
 If any refractive error…is corrected.
Upto 2 yrs it should be done in 2:1 i.e. 2 days
occlusion in normal eye and one day in
amblyopic eye.
At the age of 3… 3:1 At the age of 4….4:1
At the age of 5….5:1…..until the visual acuity
develops fully

13. i.e. blurring of vision of normal eye either by
using
Atropine (Atropine penalization) or
Over plus lenses in spectacles (optical
penalization)

14.  It works on the form of operant
conditioning(a form of psychological
treatment)
 Computerized HomeVisionTherapy (CHTV)
can prescribed as an alternative to occlusion
therapy.

15. • To re-establish
foveal fixation in
young children
Pleoptic
exercises
• Using
levodopa/carbidopa
as adjunct yo
occlusion therapy
Pharmacologic
manipulation
• Also suggested as
an adjunct to
occlusion therapy
Perceptual
learning

16.  ComprehensiveOpthalmology by
A.K.Khurana ,6th Edition.