Squint: Basics and Classification
Download
Report
Transcript Squint: Basics and Classification
Basics & Classification
Mahbuba Khondaker
PGDO Intern, School of Optometry
Aravind Eye Hospital
Introduction
Misalignment of eye visual axis
Its may congenital or acquired
It may also related with any other syndrome
In some cases it is hereditary
Is a condition which can be unilateral or bi lateral.
It is a common condition among children.
It may also occur in adults.
Squint: Definition
Squint is a misalignment of the two eyes so that both the eyes are
not looking in the same direction in same object.
The misalignment can be-
•
•
Constant
Intermittent
Causes for squint:
Birth injuries.
Hereditary.
Loss of coordination between the muscles of the two eyes
Need for glasses
Certain eye diseases interfering vision of one eye (e.g:
unilateral cataract
Illness - can make it obvious
Fatigue, stress or extended work load
Extra Ocular Muscles of Eye
Total 6 (4-rectus , 2- Oblique )
Muscles functions in particular gazes are-
•
•
•
Medial rectus (MR):
moves the eye toward the nose (Adduction)
Lateral rectus (LR):
moves the eye away from the nose (Abduction)
Superior rectus (SR):
primarily moves the eye upward and secondarily rotates the
top of the eye toward the nose (Elevation, Abduction, Intortion)
•
Inferior rectus (IR):
moves the eye downward & secondarily rotates the top of the
eye away from the nose (Depression, abduction, Extortion)
•
Superior oblique (SO):
primarily rotates the top of the eye toward the nose & secondarily
moves the eye downward (Adduction and depression)
•
Inferior oblique (IO):
primarily rotates the top of the eye away from the nose
secondarily moves the eye upward (Abduction and elevation)
Extra Ocular Muscles of Eye
Squint Classification
According to direction of deviation
According to amount of deviation in
different gazes
Squint Classification
Types of Squint and Definiton
A pseudosquint mimics a squint. It is caused
by prominent epicanthic folds causing one eye
to appear to be looking in.
Esotropia (not to be confused with entropion) is
a convergent squint, in which one eye is turned
inward.
Exotropia (not to be confused with ectropion) is
a divergent squint, in which one eye is turned
outward.
Treatment
Goals of treatment:
Development of normal vision in both eyes.
• Straighten the eyes.
• To make both eyes work together
Treatment :
• Glasses/ Spectacles:
• Some type of squint are corrected by
glass (e.g accommodative esotropia)
• Patching of the lazy eye: Stimulate bad eye to see more
and improve vision.
• Surgery : Squint correction
Types: Squint Correction
Surgery
Resection
Recession