Amblyopia (patient information): Difference between revisions
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For treatment of crossed eyes, see: [[Strabismus]] | For treatment of crossed eyes, see: [[Strabismus]] | ||
Children whose [[vision]] cannot be expected to fully recover should wear [[glasses]] with protective [[Corrective lens | Children whose [[vision]] cannot be expected to fully recover should wear [[glasses]] with protective [[Corrective lens#Polycarbonate|lenses of polycarbonate]], as should all children with only one good eye caused by any disorder. [[Corrective lens#Polycarbonate|Polycarbonate glasses]] are shatter- and scratch-resistant. | ||
==Diseases with similar symptoms== | ==Diseases with similar symptoms== | ||
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What is amblyopia?
Amblyopia (commonly referred to as lazy eye) is the failure of one eye, although otherwise physically normal, to develop normal vision and see details.
The brain and the eye work together to produce vision. Light enters the eye and is changed into nerve signals that travel along the optic nerve to the brain. Amblyopia is the medical term used when the vision in one of the eyes is reduced because the eye and the brain are not working together properly. The eye itself looks normal, but it is not being used normally because the brain is favoring the other eye. As a result, the affected eye fails to develop normal vision and see details. It has been estimated to affect 1–5% of the population.[1]
What are the symptoms of amblyopia?
Amblyopia often gives no clues to the untrained observer. In fact, many people with amblyopia, especially those who are only mildly so, are not even aware they have the condition until tested at older ages, since the vision in their stronger eye is normal. However, people with more severe amblyopia may experience associated visual disorders, most notably poor depth perception. Other symptoms include:
- Eyes that turn in or out
- Eyes that do not appear to work together
- Poor spatial acuity
- Low sensitivity to contrast
- Problems of binocular vision:
- Limited stereoscopic depth perception
- Difficulty seeing the three-dimensional images in hidden stereoscopic displays such as autostereograms.[2]
- Some "higher-level" deficits to vision, such as reduced sensitivity to motion [3]
What are the causes of amblyopia?
Amblyopia is caused primarily by one of two factors: improper alignment (known as strabismus) and unequal refractive power. If the child's eyes are not properly aligned, the brain will receive two different images from the eyes. Perceiving double vision, the brain will not use the image from the weaker eye. This eye, through lack of use, gradually loses its ability to function. The second primary cause of amblyopia is significantly unequal refractive power in the two eyes. For example, one eye may be very farsighted or nearsighted while the other eye may have normal vision. Again the brain receives different images from the two eyes and suppresses the image from the weaker eye.
Other causes of amblyopia include:
- Family history of amblyopia
- Astigmatism in both eyes
- Childhood cataracts
Who is at risk for amblyopia?
How to know you have amblyopia?
When to seek urgent medical care
Treatment options
Treating amblyopia involves making the child use the eye with the reduced vision (weaker eye). Currently, there are two ways used to do this:
- Patching: Patching is the main method used to treat amblyopia. An opaque, adhesive patch is worn over the stronger eye for weeks to months. This therapy forces the child to use the eye with amblyopia. Patching stimulates vision in the weaker eye and helps the part of the brain that manages vision develop more completely.
- Atropine: A drop of a drug called atropine is placed in the stronger eye once a day to temporarily blur the vision so that the child will prefer to use the eye with amblyopia. Treatment with atropine also stimulates vision in the weaker eye and helps the part of the brain that manages vision develop more completely.
Previously, eye care professionals often thought that treating amblyopia in older children would be of little benefit. However, surprising results from a nationwide clinical trial show that many children age seven through 17 with amblyopia may benefit from treatments that are more commonly used on younger children. This study shows that age alone should not be used as a factor to decide whether or not to treat a child for amblyopia.
The underlying condition will also require treatment. If the lazy eye is due to a vision problem (nearsightedness or farsightedness), glasses or contact lenses will be prescribed.
For treatment of crossed eyes, see: Strabismus
Children whose vision cannot be expected to fully recover should wear glasses with protective lenses of polycarbonate, as should all children with only one good eye caused by any disorder. Polycarbonate glasses are shatter- and scratch-resistant.
Diseases with similar symptoms
Where to find medical care for amblyopia
Directions to Hospitals Treating amblyopia
Prevention of amblyopia
What to expect (Outlook/Prognosis)
Vision screening by age 4 can successfully detect reduced vision in one or both eyes resulting from amblyopia. Children who receive treatment before age 5 usually have a near complete recovery of normal vision.
Delaying treatment can result in permanent vision problems. After age 10, only a partial recovery of vision can be expected.
Sources
http://www.nei.nih.gov/health/amblyopia/amblyopia_guide.asp
http://www.nlm.nih.gov/medlineplus/ency/article/001014.htm
http://www.sightandhearing.org/sightcenter/ambly.asp
- ↑ Weber, JL; Wood, Joanne (2005). "Amblyopia: Prevalence, Natural History, Functional Effects and Treatment" ([dead link] – Scholar search). Clinical and Experimental Optometry. 88 (6): 365–375. doi:10.1111/j.1444-0938.2005.tb05102.x. PMID 16329744.
- ↑ Tyler, C.W. (2004). "Binocular Vision In, Duane's Foundations of Clinical Ophthalmology. Vol. 2, Tasman W., Jaeger E.A. (Eds.), J.B. Lippincott Co.: Philadelphia".
- ↑ Hess, R.F., Mansouri, B., Dakin, S.C., & Allen, H.A. (2006). "Integration of local motion is normal in amblyopia". J Opt Soc Am a Opt Image Sci Vis. 23 (5): 986–992. doi:10.1364/JOSAA.23.000986. PMID 16642175.