It is probably the least understood disorder among the general population. Like myopia or hypermetropia, astigmatism is a refractive error. Astigmatism is caused by an error in the shape of the cornea. With astigmatism cornea, which is the front surface of the eye, has an irregular curve (cornea has a curve of a rugby ball), and the vision will be blurred, fuzzy, or distorted both at near and at distance, as the way light passes, or refracts, to retina is changed.
The symptoms of astigmatism may differ from person to person. Some people don’t have any symptoms at all. The symptoms of astigmatism include: blurry, distorted, or fuzzy vision at all distances (up close and far away), difficulty seeing at night, eyestrain, squinting, eye irritation, headaches.
It is estimated that 30% of children suffer from astigmatism and therefore it is important to consult an ophthalmologist at the smallest sign indicating a problem in a child’s vision. Otherwise, the child will not only have a decrease in quality of life, but also will face problems at school (at writing, reading, mathematics, etc.).
Astigmatism may be associated with other refractive errors (myopia, hypermetropia, or presbyopia). Astigmatism may be asymmetric (in one eye or both), and also can change over time.
The most common method of correcting astigmatism is permanent eyeglasses because the blurred vision is present both at distance and at near. They have special, cylindrical shaped lenses to compensate deformation of cornea. This shape will give an uneven thickness of the lens edge, but is not very visible to give an esthetical discomfort. At first wear of cylindrical lens glasses, the patient may experience a deformation of the surfaces, the bulging of the floor; he complains on dizziness, instability downhill stairs and sidewalks. All of these symptoms disappear fast through exercise and the patient shouldn’t give up on wearing glasses.
In some cases, astigmatism can only be corrected with the aid of contact lenses, which compensate the faulty curvature of the cornea. For high degree astigmatism, special rigid contact lenses that compress the cornea are used.
Laser surgery is recommended in selected patients. This type of surgery involves using lasers to reshape the cornea. Laser surgery can permanently correct astigmatism, but eliminating it totally is difficult to achieve.
Astigmatism in a child
About one fourth of the planet inhabitants have a so-called “physiological astigmatism” whose degree does not exceed 0.5 diopters.
Such a refractive error is not recognized by the person and does not need correction. If the degree of astigmatism is above 1.0 diopter, it usually affects visual function significantly. Astigmatism can manifest itself at any age, not necessarily in childhood. However, astigmatism could be diagnosed in children through a comprehensive eye examination beginning with the age of 2 years. At this age, the doctor can already predict the further development of the child’s visual system.
The Optisan Clinic has the equipment suitable for examination of children starting with the age of several months. With the PlusoptiX binocular autorefractometer, the primary examination of the children is very simple, without the pupil being dilated.
PlusoptiX is a very valuable visual screening device because:
- detects vision deficiencies in children from the age of 6 months. Standard tests can be used relatively late, from the age of 5 years, when the child is able to cooperate with the doctor;
- detects the risk of developing amblyopia by revealing anisometropia (differences in diopters of the two eyes) in children over 6 months;
- allows early diagnosis of strabismus;
- reveals vitreous disorders;
- alows monitoring of children with nystagmus;
- detects anisocoria, by measuring the pupil of both eyes simultaneously.
How can astigmatism be recognized?
In case your child complains on poor vision, headaches, discomfort in the supraorbital area, fast tiredness, these may indicate the presence of astigmatism. Medical examination is required not only for diagnosis, but also for prescribing glasses or contact lenses. If astigmatism is confirmed, eyeglasses or contact lenses are prescribed according to individual tolerability and age of the patient. Usually, children with astigmatism are prescribed glasses with cylindrical lenses for permanent wearing. Surgical treatment of astigmatism is recommended only after the age of 18-20 years, when the visual system is already fully developed.
Children with astigmatism should have an ophthalmologic exam twice a year. If your child wears glasses, it is important to monitor the eye growth and to change the glasses if needed.
It is important to diagnose astigmatism in time in a child, in order to take corrective measures as soon as possible and to minimize the likelihood of irreversible decrease in visual acuity, and development of strabismus and amblyopia.