Slowing or Preventing Myopia in Children
Difficulty in seeing objects at a distance can affect a child's development significantly. This nearsightedness, also called myopia, may even become progressive, with the child's vision getting worse and worse over time.
Poor vision, including myopia, can greatly hinder a child's performance in school. In fact, vision disorders are often misdiagnosed as learning disabilities before the true cause of the problem is uncovered. Make sure your child has regular eye examinations to check their eyesight, particularly before they start school, and annually thereafter, to ensure that any vision problems get swift corrective treatment. (Note: the type of vision test administered in schools is extremely limited and is not a substitute for an eye doctor's exam.) This is especially essential if you are nearsighted, as myopia tends to run in families.
You may be wondering if there is anything that can be done to slow or halt the progression of myopia once the child is diagnosed. Unfortunately, while this phenomenon has been studied for quite some time, no definitive answer has been found yet. Below are the results of some past and recent studies on myopia treatment.
One line of thought which was tried by some ophthalmologists was undercorrecting the nearsightedness when prescribing eyeglasses or contact lenses. It was thought that undercorrection may reduce the focusing strain, thought by some to be cause of progressive myopia. Studies failed to support this idea however, and some even suggested that undercorrection may increase the rate of the progression of myopia. In some studies which used bifocal lenses, myopia progression did slow significantly in the first year, compared with single vision lenses, but it was not significantly better in the subsequent years. Undercorrecting myopia was therefore concluded not to be the answer for slowing the progression of myopia, especially in children.
Rigid Gas Permeable Contact Lenses (RGPs)
Myopia in children is caused as the eyeball grows longer than normal, with a steeper cornea. This longer axial length means that light rays focusing in front of the instead of directly on it, resulting in blurry distance vision. Some studies have suggested that myopia may be slowed and controlled by wearing RGP contact lenses. The rigid lenses are thought to act as a support or splint to fortify the front of the eye without affecting the shape of the cornea. In extensive tests RGP lens wearers did show less myopia progression, but it was only temporary. However, it is not an exact science and there is some guesswork involved, since there is no way of knowing how much the myopia would have progressed had the child not worn the RGP lenses!
Soft Contact Lenses
Over the years, there has been much debate among pediatric eyecare practitioners about the effects of soft contact lenses on progressive myopia (sometimes referred to as “myopic creep”). Some believed that wearing soft contacts instead of eyeglasses put nearsighted children at a higher risk of myopic creep, but a study done presented at the 2008 meeting of the Association for Research in Vision and Ophthalmology demonstrated that this is not the case.
The study followed 484 myopic children, ages 8-11, over a period of three years. Approximately half the children wore eyeglasses, and the other half soft contacts. At the end of the study period, the researchers found no significant difference between the two groups as far as increase in eye length, increase in corneal curvature, or myopic progression. The study therefore concluded that children who wear soft contact lenses do not have a higher risk of myopic creep.
Atropine and Pirenzepine Drug Therapy
If you've ever had an eye exam where the doctor dilated your eyes, you're familiar with atropine eye drops. In studies, these eye drops were shown to reduce progressive myopia in children when administered daily. The exact mechanism for this change was unknown; some speculate that the eye drops slow the eyeball's rate of growth, while others believe that the benefit comes from the temporary paralysis of the eye's focusing muscle that the drops produce.
Unfortunately, atropine eye drops do have side effects, including sensitivity to light as well as blurred vision at near, which can negatively affect a child's performance in school and during sports, school work and other activities. Also the constantly dilated pupil can create social problems for the child, since they may be teased or be self-conscious about looking different.
Another drug which has shown some promising results in studies is pirenzepine gel, but it is not yet FDA approved and also has side effects.
Corneal Refractive Therapy (CRT)
Corneal Refractive Therapy aims to correct myopia by reshaping the cornea using specially designed contact lenses, which are worn overnight In studies, this treatment did enable wearers to see clearly the following day without corrective eyeglasses or contact lenses, but the effect was not permanent. Once the patient stopped wearing the contact lenses at night, the eyes gradually reverted to the former state of myopia. Further studies concluded that corneal reshaping did have both a corrective and a control effect in childhood nearsightedness. New studies are currently underway at Ohio University and the results are eagerly awaited.
Bookmark This Page