Astigmatism is a vision condition that can lead to blurred vision and further complications if left untreated. Learn more about the link between astigmatism and myopia in children and when and why to correct astigmatism.
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âIs it true that kids will outgrow astigmatism?â asked Sarah, a concerned mother of two. She had heard kids with astigmatism that eventually outgrew it, but she was unsure if it was just a myth.
In the US, about three in ten people aged from 5 to 17 years old had astigmatism of 1.0 D or more. Generally, mild astigmatism (< 1.00 diopter) goes away by itself by one year old, no treatment is needed. Children with larger amounts of astigmatism, especially if it is present in only one eye, may need to wear glasses or contact lenses.Â
For many children, if left untreated, astigmatism can lead to the worsening of the condition or even impact other refractive error conditions, such as myopia. In this article, we briefly discuss what is astigmatism, how it is similar or different from myopia, why we should correct astigmatism, and how it can be treated in children.
What is astigmatism?Â
Astigmatism is an eye condition that causes blurred vision. It occurs when the cornea or lens is irregularly shaped instead of curved equally in all directions. This prevents light from entering the eye and reaching the retina in a single focal point. Instead, the light is scattered in multiple focal points. As a result, objects up close and at a distance appear blurry.
There are two types of astigmatism. When the cause of the condition is due to distortion of the cornea, it is called corneal astigmatism. If the distortion is due to the lens, it is called lenticular astigmatism.
If you have astigmatism, you will have a value in the âcylinderâ column of your prescription that indicates the lens power needed to correct astigmatism. There will also be a number in the âaxisâ column that indicates the angle (in degrees) between the two meridians of an astigmatic eye, defined by a value from 1 to 180.Â
Astigmatism can affect one or both eyes. It is often present at birth and may occur in combination with nearsightedness or farsightedness. Symptoms of astigmatism in children include difficulty seeing clearly at a distance or up close, headaches, eyestrain, and squinting.
The condition tends to run in families, and children with myopia or hyperopia are at higher risk of astigmatism. Astigmatism can be diagnosed with a comprehensive eye exam and may require corrective lenses to improve vision.Â
As mentioned before, astigmatism may be present from birth, but it may develop after an eye injury, disease, or surgery. And studies indicated that it wasnât caused or made worse by reading in poor light, sitting too close to the television, or squinting.
Children with undiagnosed astigmatism may struggle in school, which teachers or parents could wrongly interpret as a sign of a learning disability.
Astigmatism and myopia explained
Myopia and astigmatism in children are both refractive errors of the eye and cause blurred vision, but myopia only affects distant objects, while astigmatism can cause blurred vision at all distances. Symptoms for the condition are similar and include blurred vision, eyestrain, headaches, and squinting.Â
Astigmatism is mainly caused by an irregularly shaped cornea or lens, while myopia is mainly caused by a longer-than-normal eyeball or a cornea that is too curved for the length of the eyeball.Â
Myopia can be inherited or acquired through environmental factors, such as lack of sufficient outdoor activities, extended periods of near work, or reading without adequate breaks. Similar to myopia, astigmatism can be inherited from one's parents, but astigmatism may also be acquired after an eye injury, disease or surgery.
Myopia can lead to other eye problems driven by elongation of the eye, such as glaucoma, cataracts, retinal detachment, and macular degeneration. In contrast, astigmatism can lead to lazy eye (amblyopia) due to vision focus problems. All of these complications are vision-threatening complications.
Does astigmatism impact myopia onset or progression?
When my son was initially diagnosed with myopia, I had many questions, including what should I do about his astigmatism and how would it impact his myopia?Â
Even though not as many studies were done on the astigmatism condition when compared to myopia, I was able to find some that were done decades ago. In 1986, a study analyzed 298 myopic children aged birth to 10 years old. It found that uncorrected astigmatism influences the course of myopia, potentially triggered by vision blurring.
Furthermore, a study published in the year 2000 that had a follow-up period of 23 years also demonstrated astigmatism in younger children is associated with an increased risk of astigmatism and myopia during the school years.Â
Researchers speculated two possible explanations for the observation. Firstly, infantile astigmatism may disrupt focusing mechanisms leading to myopia progression. Secondly, abnormal ocular growth in children induces astigmatism and myopia. The researchers also highlighted the two mechanisms are not mutually exclusive and could be operating at the same time in the same eye.
How can astigmatism be treated in children?
Treatment for myopia in children typically involves vision correction with glasses or contact lenses. Laser surgery can be considered for adults. To slow myopia progression and abnormal eye elongation in children, your doctor may prescribe myopia-control contact lenses, glasses, or eye drops.Â
Young children with astigmatism may not need treatment if they have only mild astigmatism. For children with larger amounts of astigmatism, their astigmatism can also be corrected with glasses or contact lenses -- both soft and hard contact lenses. In some special cases, a procedure called corneal cross-linking may be suggested to prevent the condition from progressing further. Laser surgery can be considered for adults.Â
Further, we may also speculate that timely correction of astigmatism may help reduce the risk of myopia onset or progression in children. More studies on this are warranted.
In addition, a comprehensive eye exam should be done at least once a year, or as recommended by your eye doctor, to monitor the condition and ensure any changes are detected.
Key takeaways
Astigmatism is an eye condition that can lead to blurred vision and, if not treated early, can cause further complications such as lazy eyes.Â
It is important to recognize how astigmatism differs from myopia and that astigmatism can lead to further deterioration of either condition if the focus problem is not addressed.Â
A comprehensive eye exam should be conducted annually - or as suggested by your eye doctor - to monitor the condition and ensure that any changes are detected, and treatments are promptly implemented if necessary.
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