Astigmatism is a condition characterized by an imperfection in the curvature of the cornea or lens, which prevents the formation of a clear image on the retina. The condition is often present at birth and is usually treated with eyeglasses, contact lenses, or surgery. A child can have astigmatism in one or both eyes.
According to a cross-sectional conducted on 9,970 children, children aged six to 12 months are approximately three times more likely to have astigmatism than children of five to six years (1). It is important to diagnose astigmatism in children at an early age, as it can affect their learning and development.
Read on as we tell you about the causes, symptoms, and treatment options for astigmatism in children.
Types Of Astigmatism
Astigmatism can be classified into two main types (2).
- Corneal astigmatism: This type occurs when there is an irregularity in the shape of the cornea.
- Lenticular astigmatism: This results from the uneven curvature and differing refractive indices within the crystalline lens.
Astigmatism can also be classified based on the refractive errors.
- Myopic astigmatism: In this type, astigmatism is combined with near-sightedness (myopia), wherein an image of a distant object becomes focused in the front of the retina. Here, distant objects appear blurred.
- Hyperopic astigmatism: In this type, far-sightedness is combined with astigmatism, and the image of the distant object becomes focused behind the retina. This makes up-close objects blurry.
- Mixed astigmatism: When astigmatism is associated with both near-sightedness and far-sightedness, it is known as mixed astigmatism (3).
What Causes Astigmatism And Who Are At Risk?
- Genetics: Astigmatism is known to run in families and is usually present at birth.
- Astigmatism may also develop following an eye injury or eye surgery.
- Keratoconus, a condition in which the cornea becomes progressively thinner and cone-shaped, may also lead to astigmatism.
- Refractive errors. Children who have myopia or hyperopia are often found to have astigmatism.
- Maternal smoking. A baby exposed to tobacco smoke either through the mother or by secondary smoking has a higher chance of developing astigmatism.
- Other factors. Pressure of the eyelid on the cornea, extraocular muscle tension, gestational age, birth weight, and medical conditions such as cerebral palsy are also known to play a role in causing astigmatism in children (1).
Symptoms Of Astigmatism
- Eye strain
- Blurry vision
Diagnosis Of Astigmatism
If you find any of the symptoms mentioned above in your child, take them to an ophthalmologist for a complete eye exam. The doctor would check the child’s vision and eye alignment and administer the following standard tests (4).
- Visual acuity assessment test
In this test, the child would be asked to read letters from a chart at a distance. This would help in determining the type of astigmatism.
The doctor would determine the curvature of your child’s cornea using a keratometer. This helps in determining the proper fit for the contact lenses.
Using a phoropter, the doctor would place a series of lenses in front of your child’s eyes and measure the focus of light.
Complications Of Astigmatism
Treatment Of Astigmatism
Your child’s doctor would suggest any of the following treatment options based on your child’s condition (4).
- Eyeglasses: Prescription eyeglasses that contain a special cylindrical lens, typically a single-vision lens, are given.
- Contact lenses: Special toric soft contact lenses are recommended for astigmatism of any type. However, caution should be exercised while using contacts for children as they need regular cleaning and care.
- Orthokeratology: In this method, a series of rigid contact lenses are fitted to reshape the cornea. These lenses are usually worn for a limited period and removed.
- Laser and refractive surgery: Surgeries such as LASIK (laser in situ keratomileuses) or PRK (photorefractive keratectomy) may be recommended to remove tissues from the superficial and inner layers of the cornea to correct astigmatism.
Prevention Of Astigmatism
As the specific cause for astigmatism is unknown, you cannot prevent astigmatism. In some children, it may get corrected on its own, while in others, treatment may be required.
Astigmatism is a common eye disorder in children that can be corrected with early diagnosis. It is imperative you observe your child’s symptoms at an early age and get a proper diagnosis done to prevent future complications.