What is Amblyopia
Amblyopia is a condition in which the vision in one or both eyes cannot be corrected to 20/20 even with glasses or contact lenses. Approximately 3% of children and young adults have amblyopia. In a child with normal visual development, the brain uses the information received from both eyes to create a clear picture. This "combining" of vision is referred to "fusing or fusion".
Amblyopia occurs when the brain is unable to fuse the two images, or one image is far too out of focus compared to the other. When the brain is unable to do this, it learns to ignore the fuzzy image, or "suppress" the information from one eye. This leads to a lack of normal development. In other words, without proper treatment, that part of the brain that is being suppressed will never learn what 20/20 vision looks like.
The term "lazy eye" to describe amblyopia is often a misnomer. It is not necessarily the eye that is lazy, but a part of the brain that must be trained. Generally, amblyopia develops while a child's brain is learning and developing. Most of this process occurs before the age of 6. Therefore it is crucial to catch and treat amblyopia as soon as possible.
Types of Amblyopia
Refractive Amblyopia - This can be due to a big difference in the prescription between the two eyes (anisometric amblyopia), or due to a high prescription in both eyes (isometric amblyopia). In anisometric amblyopia the brain may see one clear image, and one fuzzy image. This leads to a lack of "fusion" of the image, therefore the brain will typically choose the ignore the fuzzy, out of focus image. If not treated properly, this will become an amblyopic eye.
Strabismic Amblyopia (Eyeturn) - This form of amblyopia is when the eyes are misaligned and not looking at the same target. This causes double vision in the brain, and causes the brain to suppress one of the images. Not all forms of strabismus lead to amblyopia, but it is important to take the proper steps to assure that this doesn't happen.
Signs and Symptoms of Amblyopia
The main issue associated with amblyopia is poor vision in one or both eyes. A child usually does not complain because 1.) They don't know any differently than what they see and 2.) The brain may suppress the bad eye giving the child "normal" vision. Most kids easily pass simple pediatric and early school eye screenings, therefore this condition goes untreated. Only your optometrist can fully test and quantify if your child has amblyopia, and to what severity. That is why it is important to have your child's eyes tested by an optometrist by 1 year of age, and at 3 years of age.
Other signs that may suggest your child has amblyopia:
- Closing one eye to read
- Turning or tilted head to see
- Gets upset if one eye is covered up
- Continuously misjudges depth of where an object is.
Treatment for Amblyopia
The main goal of treating amblyopia is not necessarily treating the eyes, but to "teach" the brain how to see. Depending on the type of amblyopia and the severity, this can be accomplished through many different methods.
Glasses - The first step is to have the child fully corrected with glasses. If the image is not focused onto the back of the eye (retina), the brain will never learn. Depending on a child's prescription this may take some time to become fully corrected. You may hear your optometrist using words like "accepting" the prescription. Many times Dr. Miller will have to slowly build up a child's prescription a little bit at a home to achieve the best results.
Patching - This method of treatment has withstood the test of time. The treatment is straightforward, but not always simple. The child wears a patch over the good eye, with glasses on, to make the bad eye see. The duration of patching varies from case to case, but what stays the same is the need for the child to be involved in visual activities while patched.
Eye Drops - Many optometrists today are using this as a primary form of amblyopia treatment. Your optometrist may prescribe Atropine eye drops to use twice a day in the good eye. Atropine is a dilating eye drop. It will make the pupil very large, but more importantly will not allow the good eye to focus on things up close. This loss of focus will force the bad eye to carry the work load of near tasks such as reading, writing, and playing on the iPod or DS. This will also allow for a more compliant all day treatment method. A child will be very light sensitive during this treatment so your doctor may prescribe Transition lenses for their glasses or even prescription sun glasses. Again, this treatment is only successful if the child wears the prescribed glasses as directed.
Vision Therapy - If conventional treatment does not yield the expected results your optometrist may feel that vision therapy may be necessary. Vision therapy uses eye and learning exercises to "teach" the eyes and brain how to properly work together. Learn more about Vision Therapy here.
The most challenging component in Amblyopia treatment is the responsibility of the parent. Amblyopia does not occur overnight, nor will it be resolved overnight. Treatment can take many years, but is most successful in the first 3-6 months. Parents must be proactive in requiring their kids to wear the glasses as directed, use the eye drops as directed, and to patch as directed. Regardless of the acceptance of the child.
There is only a small window of opportunity to resolved Amblyopia. Usually by the age of 7 the window is closed, but new studies are showing improvement into the early teens. Regardless, the first step is to get a child's eyes examined by an optometrist within their first year, and again at age 3. If Amblyopia is present, always follow your optometrist directions and stand by them regardless of the "battle" that it may take. These steps are crucial because if your optometrist cannot teach your child's brain to see 20/20 by the time the window closes, it never will.
Amblyopia is commonly diagnosed during the GVC Kid's Eye Exam or Lifestyle Eye Exam.
Call or e-mail Gahanna Vision Center today to schedule your Lifestyle Eye Exam