CONTROL MYOPIA
In Toronto
CONTROLLING MYOPIA
ANY AMOUNT OF MYOPIA IS TOO MUCH
The elongation of the eye which takes place as myopia increases puts the eye at greater risk for eye disease. The higher myopia, the greater the incidence of diseases like glaucoma and retinal detachment.
For example, as cited in the journal Community Eye Health, “evidence concluded that the risk of developing glaucoma was nearly 50% higher (or one and a half times as high) in individuals with moderate to high myopia, compared to those with low myopia. Therefore controlling myopia is not just about improving vision, but has a direct impact on the long-term health of the eye.
Here is a table that illustrates the increased risk of other eye diseases with myopia and shows why keeping your child’s myopia at a minimum is a huge health benefit.
Our goal is to keep myopia under control. Preferably under -2.00 to -3.00.
What does -3.00 mean? Every eye has a focal point. For eyes with “perfect, 20/20 vision”, the focal point is in the far distance.
“Minus three”, in our jargon means that your child’s focal point is at 33 centimeters or 13 inches. Any object further than that will appear out of focus. But at -3.00, the eye is already stretched. It doesn’t sound like much, but a child’s eye which is -3.00 is stretched by 1mm. In other words, instead of 23mm long, it is 24 mm long. We know that eyes which are longer than 25 mm long have a much higher incidence of eye disease.
So, when monitoring any child’s vision, it is important to monitor two parameters
THE EYE GLASS PRESCRIPTION,
OR REFRACTION
THE AXIAL LENGTH
OF THE EYE
You can see that the eye on the right is myopic. How do we know? It’s longer. There is a relationship between excessive eye length and the eyeglass prescription: For every millimeter that the eye “overgrows”, your child will be -3.00 more myopic. So even though 2mm doesn’t sound like much, but for vision, it is a big problem, and for the health of the retina, it is an even bigger problem.
So, we measure vision routinely, how do we measure the length of the eye? Good question. To do this, your child needs to be measured on a biometer, such as the one shown below.
Doctors who specialize in myopia control have a biometer, which measures the length of the eye. So, what have we learned? That in order to control and manage myopia properly, children’s lifestyle, genetics, eyeglass prescription and eye length need to be evaluated and followed over time.
Controlling myopia is a combination of art and science, and is very much dependent on the experience and skill of the eye doctor. The best advice that we can give you is NOT to seek the services of myopia control in an office that “dabbles” in this therapy. If your child needed braces, you would take them to an orthodontist, would you not? The same thing applies to myopia control. Seek out an eye doctor who practices preventive eye care.
I THINK MY CHILD
IS MYOPIC,
WHAT SHOULD I DO?
Always start by getting a comprehensive eye exam, preferably by an eye doctor who practices myopia control.
After the evaluation, it is important to know several things:
1) How strong is the prescription and how long is the eye? and
2) What is the rate of change of the myopia?
This is a good place to start. Based on this information, and after a careful history, only then can a therapy be proposed for your child. Keep in mind that this is not a “quick-fix”, but a therapy that is instituted and continues until the doctor is confident that the risk of significant progression of myopia is minimal.
The science of myopia control is quite fascinating. Ordinary eyeglasses and standard contact lenses may in fact do harm by accelerating the rate of progression of myopia. We now know that myopia progression is dictated by the effect of focusing the light on the periphery (side vision) of the retina.. All contact lenses and eyeglasses that are used for myopia control specifically address focus at the sides of central vision.
In addition to using a custom contact lens, it is not uncommon to add atropine to get a better effect from the overall therapy. Therapeutic atropine for myopia control is used in three concentrations: 0.01%, 0.025% and 0.05%. This is compared to 1% which is used in eye clinics. The atropine is very dilute, as you can see, and is used at night so that the negative effect of this mild pupil-dilating eyedrop is minimal.
There is no “one-size-fits all” approach to myopia control, but the options have not been more varied for your children. It may be too late for mom and dad, but knowing what they went through, it only makes sense to minimize myopic changes in children. Once they wear -5.00 glasses it is already quite late in their progression.
There are parents who think that they will wait until they turn 20 years old, and get LASIK. The problem is that by the time your child turns 20, the stretching of the retina, or the damage if you will, has already been done.
