Introduction
The medical
name for squint is strabismus. It is a condition where the eyes do not look in
the same direction. Whilst one eye looks forwards to focus on an object, the
other eye turns either inwards, outwards, upwards or downwards. Most squints
occur in young children.
A child with a
squint may stop using the affected eye to see with. This can lead to visual
loss called amblyopia, which can become permanent unless treated early in
childhood. This treatment usually involves patching the good eye, to force the
use of the affected eye. Sometimes surgery is needed to correct the appearance
of a squint.
What is Squint
Squint is a misalignment of the two
eyes so that both the eyes are not looking in the same direction. This
misalignment may be constant, being present throughout the day, or it may
appear sometimes and the rest of the time the eyes may be straight. It is a common
condition among children.
When the eyes are not aligned properly, each of the eyes is focusing on a different object and sends signal to the brain. These two different images reaching the brain lead to confusion and may have either of the two effects:
A child would ignore the image coming from the deviated eye, and thus sees only one image. But in the process, he loses the depth perception. This suppression of the image from the deviating eye results in poor development of vision in this eye, which is known as Amblyopia.
When the eyes are not aligned properly, each of the eyes is focusing on a different object and sends signal to the brain. These two different images reaching the brain lead to confusion and may have either of the two effects:
A child would ignore the image coming from the deviated eye, and thus sees only one image. But in the process, he loses the depth perception. This suppression of the image from the deviating eye results in poor development of vision in this eye, which is known as Amblyopia.
Types of strabismus
There
are different types of strabismus. They can be described by the cause or by the
way the eye turns. The following terms describe strabismus by the positions of
the eye:
- Hypertropia is when the eye turns upwards
- Hypotropia is when the eye turns
downwards
- Esotropia is when the eye turns inwards
- Exotropia is when the eye turns outwards
An
early diagnosis of strabismus will enable more effective treatment.
What are the symptoms of Squint Children
The sign of a squint is fairly obvious from an early age.
One of the eyes does not look straight ahead. A minor squint may be less
noticeable. Infants and newborns may go cross-eyed, especially if they are
tired. This does not mean that they have a squint. Parents can check with their
doctor.
If a child has one eye closed, or turns their head when
looking at you, this could be a sign of a possible squint. Strabismus is
normally either present at birth or it develops in the first 6 months after
birth.
In a child, the parents may notice the
deviation of eyes. It is important to remember that the eyes of a newborn are
rarely aligned at birth. Most establish alignment at 3-4 weeks of age.
Therefore squint in any child who is more than one month old must be taken
seriously and should be evaluated by an ophthalmologist.
A squint can be a cosmetic problem. Many older children and adults who did not have their squint treated as a child have a reduced self-esteem because of the way their squint looks.
A squint can be a cosmetic problem. Many older children and adults who did not have their squint treated as a child have a reduced self-esteem because of the way their squint looks.
The exact cause of squint is not really
known. The movement of each eye is controlled by six muscles that pull the eye
in various directions. 
A
squint develops when the eye muscles do not work in a balanced way and the eyes
do not move together correctly. This loss of coordination between the muscles
of the two eyes leads to misalignment. This misalignment may be the same in all
directions of gaze, or in some conditions the misalignment may be more in one
direction of gaze, e.g., in squint due to nerve palsy.
A
squint develops when the eye muscles do not work in a balanced way and the eyes
do not move together correctly. This loss of coordination between the muscles
of the two eyes leads to misalignment. This misalignment may be the same in all
directions of gaze, or in some conditions the misalignment may be more in one
direction of gaze, e.g., in squint due to nerve palsy.
Strabismus can be:
- congenital,
meaning a person is born with it
- hereditary,
or running in families, suggesting a genetic link
- the result of an illness or long-sightedness
- due to a lesion on a cranial nerve
If the eye cannot focus the
light as it comes in through the lens, this is known as a refractive error.
Other problems that can lead to
strabismus include:
- myopia,
or short-sightedness
- hypermetropia,
or long-sightedness
- astigmatism,
where the cornea is not curved properly
A refractive error tends to make
the affected eye turn inward, in an attempt to get better focus. Strabismus
that results from refractive errors tends to emerge later on, usually around
the age of 2 years or older.
Diagnosis and treatment
Children and babies should have routine
eye checks as they develop. The American Optometric Association recommends
starting eye tests at 9 months, or earlier if the child has a constant eye
turn. If there are signs of strabismus, the physician or optician will refer
the child to an ophthalmologist.
The ophthalmologist will probably use eye
drops that dilate the pupils before the test is done. The Hirschberg test, or
Hirschberg corneal reflex test, is used to assess whether the patient has
strabismus.
The ophthalmologist shines a light in the
eye and observes where the light reflects from the corneas. If the eyes are
well-aligned, the light will go to the center of both corneas. If it does not,
the test can show whether the patient has exotropia, hypertropia, esotropia or
hypotropia.
Treatment
options
Prompt treatment reduces the risk of
complications, such as amblyopia, or lazy eye. The younger the patient is, the
more effective treatment is likely to be.
Treatment options include:
- Glasses:
If hypermetropia, or long-sightedness, is causing the squint, glasses can
usually correct it.
- Eye
patch: Worn over the good eye, a patch
can get the other eye, the one with the squint, to work better.
- Botulinum
toxin injection, or botox:
this is injected into a muscle on the surface of the eye. The doctor may
recommend this treatment if no underlying cause can be identified, and if
signs and symptoms appear suddenly. The botox
temporarily weakens the injected muscle, and this can help the eyes to
align properly.
- Eye
drops and eye exercises
may help.
Surgery is only used if other treatments
are not effective. It can realign the eyes and restore binocular vision. The
surgeon moves the muscle that connects to the eye to a new position. Sometimes
both eyes need to be operated on to get the right balance.
Exercises
A standard type of exercise for
strabismus is home-based pencil pushups (HBPP).
To do HBPP, follow these steps:
- Hold a pencil at arm's length, around midway
between the eyes
- Look at the pencil while moving it toward the
nose, and try to maintain a single image of it
- Keep moving the pencil toward the nose until
you can no longer see it as a single image
- Hold the pencil at the closest point where a
single image is possible
- If you cannot regain a single image, start
again
A study of patients who did two
sets of 20 "push-ups" each day for 12 weeks suggested that the
exercise can be "an easy, cost-free, and effective therapy."
Conclusion
Treatment of strabismus and amblyopia in
childhood reduces the risk of later visual and employment disadvantage and
maintains a more stable ocular alignment. Treatment of amblyopia in adulthood
is not yet a possibility. There will be an increasing trend to early squint
surgery in young children and an increase in demand for strabismus surgery in
elderly patients.
References:
·
http://www.medicalnewstoday.com/articles/164512.php
Informative and wonderful blog. Goot to read this. Squint is an eye disorder. My sister was also suffered from this problem and she got Squint Eye Surgery treatment from Mitra Eye Hospital. Now, her eyes are normal.
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