Strabismus and Amblyopia

Amblyopia or “Lazy Eye,” the most common cause of visual impairment among children, according to the National Institute of Health, is defined as reduced vision in one eye compared to the other. There are some types of amblyopia where both eyes are affected. In addition to the fact that one eye does not see clearly, recent research shows that patients with amblyopia often have trouble using their two eyes together as a team. The brain the starts to suppress, or ignore, information coming from one eye.

Reasons why amblyopia (lazy eye) may develop:

  • Refractive: differences in the refractive status (prescription) between the two eyes due to farsightedness, nearsightedness or astigmatism
  • Strabismic: constantly misaligned eyes; one eye may turn inward or outward
  • Obstructive: constant obstruction of vision from one eye during early childhood (droopy eyelid, cataract, etc.)

Most children with amblyopia have no symptoms! Because one eye sees very well, the patient is frequently not aware that the other eye is seeing poorly. People with amblyopia can have difficulty with depth perception, eye movements used for reading, and reaction time. Comprehensive eye examinations for children beginning at 6 months of age are the best way to detect amblyopia, and early treatment often yields the best results.

How is amblyopia treated?

  • A comprehensive vision evaluation will determine if eyeglasses or contact lenses are needed. The correct prescription can greatly improve vision in the weaker eye, and allow the brain to start to take in more information from that eye instead of ignoring it.
  • Patching or penalization of the better seeing eye can “force” the brain to use the information from the weaker eye. However, patching does not teach the brain to use both eyes together in a coordinated way, so it may not be the only treatment needed to fully correct the problem and maintain the improved vision.
  • The newest research shows that an individualized program of advanced Vision Therapy can help improve the visual abilities of the eye with amblyopia including:
    • Accommodation (focusing)
    • Oculomotor (eye tracking) skills: fixation, saccades, pursuits
    • Spatial (eye-hand coordination) skills
    • Binocular (eye-teaming) skills

**Vision Therapy can greatly reduce the frequency of patching needed to improve vision in the weaker eye since the goal of amblyopia therapy is to improve eye coordination, improve stereopsis (depth perception), and reduce suppression.**

Strabismus or “Crossed Eyes” is defined as the inability to point both eyes in the same direction at the same time. One eye may turn inward (esotropia) or outward (exotropia), or upward (hypertropia) or downward (hypotropia). The turned eye may always be the same eye (monocular/unilateral) or the turned eye may switch (alternating). It may occur some of the time (intermittent) or all the time (constant). Crossed eyes can develop in infants and children, or in adults.

Why does Strabismus develop?

  • Inadequate development of eye coordination in childhood
  • A high amount of hyperopia (farsightedness) or differences between the vision in each eye
  • Problems with the eye muscles that control eye movement
  • Traumatic/acquired brain injury, stroke, or other health problems

How is Strabismus treated?

  • Eyeglasses
  • Vision therapy
  • Eye muscle surgery

Frequently, patients with strabismus require both eyeglasses and vision therapy to help align the eyes. Eye muscle surgery may also be necessary in some cases. Even for patients that do require eye muscle surgery, vision therapy before and after surgery can prove very beneficial and improve the end result, helping the eyes stay better aligned over time. In some cases, completion of vision therapy can make surgical intervention unnecessary. A full evaluation is needed to determine the proper treatment plan for each individual patient.