Strabismus (Squints)

Overview

Strabismus or squints are a problem caused by one or more improperly functioning eye muscles, resulting in a misalignment of the eyes. Normally, each eye focuses on the same spot but sends a slightly different message to the brain, the brain then processes these images to produce a full 3D effect, providing depth perception.

Each eye has six muscles that work in unison to control movements. The brain controls the eye muscles to keep the eyes properly aligned. It is critical that the muscles function together for the brain to interpret the image from each eye as a single one.

Children adapt to strabismus very easily, their brains simply reprogram themselves to suppress incorrect images and ensure single vision rather than a consused picture. The danger with this is that there is a tendency for the brain to permanently ignore the vision from the out of line eye, this causes weak or ‘lazy’ eyes. Adults brains are harder to reprogram, so adults with a newly acquired strabismus can’t readily process the conflicting signals and so the adult has ‘double vision’.

Strabismus can be caused by many things, certain diseases can trigger it, it can be inherited or it may be caused by trauma or after eye surgery.

Signs and Symptoms

As previously described, because their brains are harder to repgrogram, Adults are much more likely to be bothered by symptoms from strabismus than young children. Children should undergo vision screening exams to detect problems early. The younger the child is when strabismus is detected and treated, the better the chance of normal vision. The following are common signs and symptoms:

  • Turned or crossed eye
  • Head tilt or turn
  • Squinting
  • Double vision (in some cases)

Detection and Diagnosis

Strabismus is detected with a comprehensive eye exam and special tests used to evaluate the alignment of the eyes such as: the Krimsky test and prism testing.

Treatment

The appropriate treatment for strabismus is dependent on several factors including the patient’s age, the cause of the problem, and the type and degree of the eye turn. Treatment may include patching, corrective glasses, prisms, or surgery.

With patching, the better eye is covered, forcing the child to use the weaker eye. Over time, the brain adjusts to using the weaker eye and vision gradually improves. For this treatment to be effective, it must be done at a young age.

Surgery is sometimes performed for both adults and children to straighten a crossed eye. The procedure may be done with local or general anesthesia. There are several different surgical techniques used to correct strabismus. The appropriate one is dependent on the muscle involved and the degree of the eye turn.