Amblyopia

Overview


Amblyopia, also known as "a lazy eye," is defined by the American Optometric Association as " the loss or lack of development of central vision in one eye that is unrelated to and is not correctable by any lenses." Amblyopia can occur even when there is no problem with the structure of the eye. Amblyopia is caused by the result of both eyes failing to work together. The visual stimulation either fails to transmit or is poorly transmitted to the optic nerve. In most cases amblyopia only affects one of the two eyes, this can result in a large disparity between, the strength of the eyes or the degree of farsightedness or nearsightedness in the eyes. The difference between the two eyes causes the brain to use the stronger, more dominant eye in turn making the non-dominant eye weaker.

Symptoms


As a child's brain matures, it will begin to naturally ignore the images that are blurry or that it has trouble seeing, so in this aspect early detection is key. Symptoms may be difficult to notice, especially in less severe cases.

Symptoms include:
  • Noticeably favoring one eye (i.e always bumping into things with the same side of their body)
  • Poor Visual Acuity
  • Poor Depth perception
  • Eyes that appear not to work together
  • Eyes that wander inward or outward
amblyopia.jpg
amblyopia.jpg

Example of a wandering eye
As mentioned the majority of these symptoms are difficult to see and in the more mild cases may not even appear. It is recommended to get children checked as early as six months by eye-care professionals so corrective action can take place as soon as possible. A fully comprehensive eye exam is the only way to diagnose amblyopia.

Treatment


There is no set treatment for amblyopia it varies from patient to patient based on age and severity of the disorder. It is usually a combination of prescription lenses, prisms, eye-patching and and vision therapy.

  • "Patching the eye"- This type of treatment method is exactly what it sounds like. This method forces the bad eye to work by patching the good eye. The patching in most instances is done with an actual eye patch that doesn't keeps the strong eye in total darkness for the majority of the day. This method is only put into place which preexisting conditions in the " bad eye" such as farsightedness or nearsightedness have been taken care of.
    • Atropine is a solution used in more mild cases that takes the place of an eye patch. This just blurs the vision in the "good" causing the "bad" eye to most of the work.
  • Surgery- In some cases surgery may be needed to help a patient fully correct their vision but this is only in severe cases. Such as having a cataract that is blocking the light from getting behind the eye or having strabismus which can prevent the eyes from working together.
  • Medication- The less successful way to treat amblyopia is to add eye drops to the predominant eye to blur it’s vision. This makes the weaker eye work and become stronger. This usually doesn’t work especially when the stronger eye is nearsighted.
Types of Amblyopia

There are three types of amblyopia each of them result in a decrease in vision in the affected eye or eyes. The names of the types are as follows: Strabismic amblyopia, deprivation amblyopia, and refractive amblyopia.
Related Terms

  • Crossed eye
  • Astigmatism
  • Hyperopia
  • Myopia
  • Anisometropia

Resources

__American Optometric Association__
__WebMD__
__Mayo Clinic__
__National Eye Institute__
__Preventblindness.org__
__American Association for Pediatric Ophthalmology and Strabismus__