Strabismus and Orthoptic

Strabismus

This is a disorder in which the two eyes are not aligned in the same
direction, and therefore do not look at the same object at the same time. It is
commonly known as squint or even ‘cross-eyedness’.

Causes

Six different muscles surround the eyes and they should work ‘as a team’ for both eyes to focus on the same object at the same time.

In someone with strabismus, these muscles do not work together. As a result, one eye
looks at an object while the other rotates in a different direction and focuses elsewhere.

When this occurs, two separate images are sent to the brain – one for each eye. This confuses the brain, which learns to ignore the image from the weaker eye.

If the squint is not treated, the eye that the brain ignores will never see well. This loss
of vision is called amblyopia, or ‘lazy eye’.


Amblyopia may also be caused by the need for eyesight correction with glasses 
or by a great difference in graduation between the two eyes. It is sometimes the
primary cause of the strabismus.


In most children with strabismus, the cause is unknown. In over half the
cases, the problem was present at birth or shortly thereafter (congenital strabismus).


Most of the time, the problem is related to muscle control, not to
muscle strength.

Associated disorders

• Diabetes (causes a condition known as acquired paralytic strabismus).
• Damage to the retina in premature babies.
• Haemangioma near the eye during infancy.
• Eye lesions.
• Tumours in the brain or eyes.
• Vision loss associated with any eye disease or lesion.
• Disorders of the brain or nerve endings, such as brain damage, paralysis, stroke,
  or Guillain-Barre syndrome.

Furthermore, a family history of the disease is a risk factor, as is long-sightedness, especially in children.


Any other condition that causes loss of vision may cause strabismus.

The symptoms

Its symptoms may be present constantly or only when tired or sick.

The eyes do not move together and sometimes appear crossed. One eye seems to be
looking the other way when the other is focusing on an object.

A person with strabismus may also have: loss of depth perception,
double vision and/or vision loss.

Orthoptics

Orthoptics is a specialty of Optometry responsible for the assessment and measurement of
mild, moderate and severe deviations of the eye-muscles.
It also deals with the stimulation and management of amblyopia (lazy eye), optometric problems in children and the recovery of disturbed visual functions.

Among its treatment methods are the
use of glasses, eyepatches and certain kinds of specific exercises.

If appropriate eye movement is not achieved, the surgical option may be
 necessary. Such surgery does not restore lost vision to the lazy eye, but it can help reduce the degree of
squinting. That is, after surgery the eyes should be able to look at one point at the same time, but vision problems can remain. In general, the younger the
child when the surgery is done, the better the results.

Adults with mild strabismus that comes and
goes can be treated and become comfortable with glasses or special exercises. More
 severe forms in adults may also need surgery to straighten the eyes.

If the 
squint is due to loss of vision ( for example cataracts) the cause should first be solved.

Patch and strabismus