Mahbuba KhondakerPGDO Intern, School of Optometry

Aravind Eye Hospital

Basics & Classification

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 EyeTotal 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