What is accommodative esotropia?
Accommodative esotropia (convergent squint), refers to an inward turn of one eye, and is caused by the focusing efforts of the eyes as they try to see clearly. Patients with accommodative esotropia are typically longsighted (hypermetropic, or hyperopic). This means that the eyes must work harder to see clearly, particularly when the object is up close. A side effect of this focusing effort can be excessive convergence, or crossing of the eyes.
Why is accommodative esotropia a concern in children?
If a child’s eyes cross at an early age, then vision may not develop normally. Vision can be reduced in one eye (amblyopia) if it is not “used” properly during childhood, and fine depth perception may never develop.
Crossing of the eyes is never normal. However, some babies or small children may look like they have a turn in the eye, but on examination, actually be normal. This is called a pseudosquint.
How is accommodative esotropia treated?
Initial treatment for accommodative esotropia usually involves the prescription of glasses for the long-sightedness. By letting the eyeglasses do the work, the eyes can relax their focusing. This will reduce the convergence or crossing, and the eyes will straighten as they relax.
Glasses which are used to treat accommodative esotropia should be worn full time.
What happens after a child starts wearing glasses for accommodative esotropia?
Once the child has settled in to their glasses their eyes may become fully straight with their glasses on, or partially straight with their glasses on. The child will typically have their vision tested with their orthoptist every two to three months to monitor their progress. If the vision is reduced in one eye, this is called amblyopia, and patching treatment may be required.
Will my child require surgery?
Surgery is only indicated if the eyes are still significantly crossed even with the glasses on. Your orthoptist or ophthalmologist will advise if and when this is an appropriate course of action. Surgery for accommodative esotropia does not eliminate the need for glasses but rather fixes the amount of crossing that is “left-over” when the glasses are on. The eyes will likely continue to cross somewhat when the glasses are off.
My child’s eyes look quite straight with their glasses on but I still notice their eyes crossing without their glasses!
Even after a child has been successfully wearing glasses to treat accommodative esotropia, it is still normal for the eyes to continue crossing without the glasses. In fact, sometimes the crossing may be even more noticeable than it was before the child started wearing glasses as they focus harder than ever to achieve the clarity of vision they get with their glasses. The important matter is their vision, and whether or not the eyes are sufficiently straight and controlled with the glasses on.
Why do some children with accommodative esotropia require bifocals?
In some cases, children will have particularly excessive amounts of eye crossing (esotropia) when looking at objects up close, such as while reading. These children may benefit from making the lower, reading area of the eyeglasses “extra strong” in the form of a bifocal lens, as shown here:
Can children outgrow accommodative esotropia?
Yes, children can outgrow accommodative esotropia. This usually happens during the late primary school and adolescent years as a child becomes less longsighted. It is difficult to predict early in childhood whether or not any given child will outgrow their need for glasses. As a general rule children requiring a prescription of +4.00 or more will rarely completely outgrow their glasses.
Will my child be suitable for contact lenses or refractive eye surgery?
Yes in most cases when they are old enough (current recommended age 21) they can seek refractive surgery. Once treated, you can expect the esotropia to be very similar to that with their glasses on.
Contact lens treatment is at the discretion of the optometrist. A typical age to start contact lenses might be between 14 and 16 years, with awareness of good hygiene being of the utmost importance.