Exotropia refers to an outward deviation of the eyes. Although Exotropia commonly begins around age 2 to 4 years, it can appear at any age.

What will I see my child's eyes doing?

Initially, you may only notice that one eye turns out when your child is tired or not feeling well. Typically an out-turning eye is more noticable when the child looks in the distance and not as much when viewing close objects. Your child may be seen squinting or rubbing one of the eyes. A child with exotropia may close one eye particularly in bright sunlit environments. Few children will complain of double vision.

How does it affect my child?

The vision in each eye is usually normal in this condition, and often the 2 eyes can work together some or even most of the time, so binocular vision is possible. It is not until the out-turn begins to occur under normal viewing conditions that it may make vision more difficult for your child. If a stage is reached when either eye is constantly turned then the ability to use the 2 eyes together can be lost over a period of a few months, and this may or may not return if the eyes are re-aligned. It is also in this situation that amblyopia can develop, if one eye in particular is always turned.

Occasionally a constantly out-turned eye may be the first sign of a problem that has impaired the vision in one eye, so that it 'wanders' to where-ever it wants to. This is one reason why it is important to have your child's eye examined promptly & fully, with pupil dilation and examination of the retina, especially if they are young (<2 years old) when the out-turn begins.

Treatment

A full eye examination may reveal the presence of a refractive error  (the eyes are out of focus), which is a common reason why a strabismus may develop, and needs to be corrected before any other treatment is considered. Sometimes it is worth a trial of glasses which are made so that your child must exert focusing power to see, because focusing on a near object is strongly linked to the eyes turning inward. But glasses may not fully correct the problem, and if the eyes have a very large turn glasses are often not effective at all.

Other treatment such as prism power in the glasses have been used in the past to keep children using the 2 eyes together, but these will be only helpful in a minority of selected cases and shouldn't be used as routine treatment (they are expensive and seldom work in cases where the child was not able to control the problem themselves without the prism).

Exercises to increase converging ability are of no help in intermittently or constantly present exotropia. There is one group of patients who have a different alignment problem known as 'Convergence Insufficiency' who have been shown to benefit from eye "exercises", but this is a very specific problem where the eyes tend to turn out as the person looks at close objects , rather than in exotropia where the turn is greater and harder to control with things far away.

Surgery 

Surgery is generally recommended if one or more of the following criteria are present:

  • If the degree of the turn is large.
  • If the exotropia is noted very frequently, ie more than 10-15 times each day, or is 'constant' (there 50% or more of the time).
  • If the frequency of the exotropia is definitely increasing, showing that the child's ability to control it is worsening.
  • If there is a significant exotropia when your child intently views objects at near (ie they are unable to use the 2 eyes together - binocular vision has been lost).
  • If there is other evidence that your child is losing "binocular vision." This refers to the brain's ability to use both eyes together as a single unit. Among other benefits, binocular vision affords optimal depth perception.

 

What Surgery involves

Muscle surgery in children requires general anaesthesia. With the amount that most eyes turn out when surgery is needed, 2 or sometimes 3 muscles need to be operated upon, and sometimes this is spread between both eyes (see FAQ-Strabismus surgery).

Surgery is generally very effective, & serious complications are very rare, however glasses and/or patching of the eyes may still be necessary afterwards and it is very important that the child is seen for at least 12 months afterwards to ensure they maintain good vision. Up to 20% of children will require a further operation at some stage in their lives to keep the eyes fully aligned (ie in a small number it changes at some stage in adulthood).

Will My Child Outgrow This Problem?

If the exotropia is milder, or if none of the four treatment criteria listed above are applicable, then around 2/3rds of children will be able to continue to control the problem and avoid surgery, but 1/3rd will still become worse and benefit from surgery over time. However, if the exotropia is significant and meets any of the four criteria listed, it is very unlikely that the exotropia will improve without surgery.

Why Is Good Ocular Alignment Important In Childhood?

Aside from the obvious improvement in your child's appearance when misaligned eyes are corrected, there are other functional benefits to consider. When a significant ocular misalignment exists in childhood, the brain's developing visual system does not acquire binocular vision. Aside from improved depth perception, a person with binocular vision tends to maintain good ocular alignment throughout life, and they have a decreased risk for developing amblyopia.