There are two major forms of childhood esotropia (and many less common causes).

A.     Accommodative Esotropia

The most common form of childhood esotropia occurs because of high hyperopia (if this applies to your child, then Dr. Lichtenstein will give you information about hyperopia).  With hyperopia, everything is blurry until the brain sends a signal to the lens inside of the eye to change shape – this puts images into focus and sends a clear picture to the brain.  (The process of the natural lens changing shape is accommodation.)  At the same time that the natural lens changes shape (accommodates), the eyes turn inwards (eso-deviate) – this is a hard-wired reflex and applies to everyone. 

With high hyperopia, the necessary lens change (accommodation) is large, so the corresponding eye turn (eso-deviation) is large.  

This type of esotropia typically presents around the age of 2 or 3 years and is called accommodative esotropia.  Often, accommodative esotropia starts out as a “once in a while” problem and becomes more and more frequent; sometimes, babies as young as a few months can be affected.

Accommodative esotropia is managed by putting hyperopic glasses in front of the eyes to relax accommodation.  If the lens inside the eye is not doing the work of accommodating, then the eyes will not turn in – thus, wearing glasses controls the esotropia.  . Sometimes, even when the appropriate hyperopic glasses are used full time, the eyes still turn in; this is called a residual esotropia and surgery may be indicated for correcting the residual amount of esotropia (remember, glasses are still needed after surgery to keep the eyes straight).  

B.     Infantile Esotropia

The other major category of esotropia is called infantile esotropia.  As the name implies, the eyes turn in because of a problem that manifests early in life; by definition, these patients display their esotropia within the first 6 months of life. 

Many pediatric ophthalmologists believe that people with infantile esotropia have a basic predisposition in the brain for the problem and something in their environment causes the problem to manifest.   The ideal treatment for this condition would therefore involve "tweaking" that part of the brain that is misbehaving.  Unfortunately, the exact location of this defect remains unknown and the ability to "tweak" brain problems has not been developed yet. Instead, this problem is treated by surgically aligning the eyes to a straight position. If this is done at an early enough age, the brain can learn where "straight-ahead" is for the eyes. 

In fact, there is evidence that some form of depth perception (binocularity) can be established by early surgery (before the age of 2 years, but earlier is better).   It is important to remember that the basic problem remains; the brain’s control of eye alignment is essentially faulty. People with congenital esotropia are more likely than other people with strabismus to develop other types of strabismus and to require further surgeries.   While on average, two surgeries are required, about 80% of people with congenital esotropia require just one surgery to achieve straight eyes.