Childhood Strabismus

What is strabismus?

Strabismus, more commonly known as cross-eyed or lazy eye, is the condition where:

  • both eyes can’t align simultaneously under normal conditions
  • one or both of the eyes may turn in, out, up or down
  • an eye turn may be constant (when the eye turns all of the time) or intermittent (turning only some of the time, such as when ill or tired)

Whether constant or intermittent, strabismus needs appropriate evaluation and treatment. Children do not outgrow strabismus!

Strabismus vs “lazy eye”

The term lazy eye is often used to describe strabismus, which is not entirely accurate. Lazy eye usually refers to the presence of poorer vision in one eye over the other, clinically known as amblyopia.

Amblyopia develops in children when they have a strabismus that is present most of the time and mainly in one eye. As the brain cannot make sense of the images received from the two eyes, it ignores the image from the turned eye. If left untreated this results in poor vision in the turned eye. This is called amblyopia.

Amblyopia is often present in adults who had a strabismus in childhood. Amblyopia cannot be treated past the age of 8 years, and glasses will not improve the lost vision later in life.

Amblyopia may also be due to other factors present in childhood that restrict the development of visual function, like cataract, ptosis (droopy eyelid), or undiscovered imbalance in refractive error (the need for glasses).

How is amblyopia treated?

The first step in treating amblyopia involves addressing any need for glasses. The ophthalmologist will perform a cycloplegic refractionto determine the strength of the glasses. This involves using drops to inhibit the eyes’ ability to change focus and will also dilate the pupils, allowing the doctor to check the health of the back of the eyes. These drops are not painful (they may sting for a few seconds, like getting water in your eye) but they are long lasting, so your child’s pupils will remain large for several hours.

If glasses have not brought the vision up to an acceptable level, the next option is occlusion therapy. This involves occlusion - the covering - of the eye that has better vision to force the brain to recognise the poorer eye. The occlusion (usually a patch, either pirate style or adhesive for smaller children) may need to be used for 2-6 hours daily, depending on the severity of the loss of vision. In some cases drops may be used in place of the patch. These drops are put in the good eye to blur the vision, again forcing use of the poorer eye.

It is important to remember that when your child is wearing the patch their visual awareness is severely diminished and extra supervision is required if moving around in a crowded area.

No matter what method is prescribed by the ophthalmologist it is important to comply with the treatment to the best of your ability. It can be difficult to get children to cooperate, especially when it is something that they must do every day. However it is important that vision is improved before the brain stops developing at 8 to12 years. Any reduced vision after this stage is permanent and may affect your child’s functioning in adulthood like meeting driver’s license requirements and some work requirements.

Will wearing the patch straighten my child’s eyes?

Occlusion therapy is used purely to improve vision in the poor eye. Surgery is required to improve the alignment of the eyes.

Strabismus surgery

Surgery to improve the alignment of the eyes may be performed on one or both eyes, even if it is only the one eye that turns. The surgery is performed in hospital under a general anaesthetic.

Realigning the eyes may be performed to improve the eyes’ ability to work together (improving depth perception), to eliminate double vision, or purely to straighten the eyes for cosmetic reasons which is often the case in adults, or when the turned eye has permanently poor vision.

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