Why does your child’s prescription seem to get worse every year?
What can be done about it?
Myopia Management has been developed to try to answer these important questions.
The steady progression in the strength of a myopic prescription is more than an inconvenience, it’s also a potentially serious risk to long term eye health.
Recent studies have indicated that there isn’t a “safe” amount of myopia, so lets discuss what we can do!
What is Myopia?
Myopia is the refractive error of the eye that results in blurred distance vision.
It is the result of the length of the eye (axial length) being longer than it should be, the power of the internal lens of the eye (crystalline lens) being too strong, the power of the cornea (clear part of the front of the eye), or a combination of all of them.
Myopia is sometimes referred to as “near sighted” because when an object is brought closer to the eye, there is a specific distance (depending on the amount of myopia) in which that object will be clearly seen.
Click to see an animation describing myopia
What are the Risk Factors for Myopia?
The myopic risk profile can be helpful to determine if a child is at a greater risk for developing myopia.
- Age – Myopia develops during early to middle childhood ages and progresses before stabilizing (usually) in late adolescence. Myopia also seems to progress faster at a younger age.
- Refractive Error – If a child’s prescription is more myopic than would be expected for their age.
- Ethnicity – Highest prevalence of myopia is in children of eastern and southern Asian descent. 65% of the population in China, 81% in Taiwan and 97% in South Korea. Incidence of myopia is lower in the rest of the world. 35% of the population of Europe is myopic and only 6% of the population of Ethiopia and Tanzania.
- Parental Myopia – If one parent is myopic, the child is at a 3 times greater risk of developing myopia. If two parents are myopic, the child is at a 6 times greater risk of developing myopia.
- Time Spent Outdoors – The highest associated environmental risk is low outdoor time; less than 1.5 hours per day outside. Moderate risk with 1.5-2.5 hours per day, and lowest risk with more than 2.5 hours per day.
- Time Spent with Near Work – The highest associated risk long hours spent with close work (smart phones, tablets, reading, computer, homework, etc) of longer than 2.5 hours per day. Moderate risk is 1.5-2.5 hours per day, and lowest risk with less than 1.5 hours per day.
If a child has 5 or 6 of these risk factors, there is a high risk of developing myopia.
If a child has 3 or 4 of these risk factors, there is a medium risk of developing myopia.
If a child has 0 to 2 of these risk factors, there is a low risk of developing myopia.
What Causes Myopia Progression?
A child’s risk of developing myopia is influenced by genetics. If one or both parents are myopic, the child’s risk of becoming myopic (nearsighted) is three times to six times more likely, respectively, to become myopic as well.
Environment also plays a role in a child developing myopia. A child who spends a significant amount of time working at a near distance (phone, tablet, reading, computer, etc.) and a limited amount of time outdoors is at a three times greater risk of developing myopia when compared to a child with limited near work and higher outdoor time.
Outdoor light has a different composition than indoor light and is up to 100 times greater than indoor illumination. It is theorized that both of these may play a role in developing myopia.
However, while it has been determined that outdoor time increases risk of developing myopia, it is unclear if outdoor time helps slow myopia progression.
As children grow, their eyes can grow as well. As the eye grows, the amount of myopia will increase.
What is Myopia Management?
Myopia Management is a term used to describe various treatment methods used to help slow down the progressive loss of distance vision.
These methods include ortho-keratology (ortho-k), which uses specially designed RGP contact lenses to gently reshape the cornea while sleeping, to provide clear vision during waking hours without glasses or contact lenses.
Multifocal Soft Contact lenses, which are worn during the day.
Low Dose Atropine (0.2%) drops used daily before bedtime.
Why is Myopia Management Important?
Myopia is becoming an epidemic throughout the world, and there is no “safe” level of myopia.
The prevalence of myopia in the United States is estimated to between 33-42% of the population (almost 100 million Americans), which has doubled since 1972.
In China the prevalence is higher, estimated to be 65% of the population and in other eastern Asian countries the prevalence is even greater than that. In Taiwan, 81% of the population is myopic, and in South Korea, 97% of their population is myopic.
The World Health Organization has estimated that by 2050, 50% of the world’s population will by myopic, and of those, 10% (1 billion people) will have severe myopia; defined as greater than or equal to -5.00D of myopia.
Besides the progressive loss of clear distance vision there are health risks that can result from increased levels of myopia. The higher the amount of myopia the greater the risk of developing cataracts, glaucoma, posterior vitreous detachment, myopic macular degeneration, posterior staphyloma and retinal tears and detachments, to mention a few.
· The risk of glaucoma is 14.4 times higher for a person with -6.00D of myopia when compared to a person with no myopia (emmetropia).
· The risk of retinal detachment is 7.8 times higher for a person with -8.00D of myopia when compared to a person with emmetropia
· The risk of cataracts are 3.3 times higher for a person with -6.00 D of myopia compared to a person with emmetropia.
· The risk of myopic macular degeneration is an alarming 40 times greater risk for a person over -5.00D of myopia compared to a person with emmetropia.
As more and more studies show the efficacy and safety of myopia management treatments, controlling myopia has come to be viewed as more of a necessity than an elective luxury by eye care professionals, educators and parents.
Benefits of Myopia Management Treatments
Unfortunately, myopia cannot be “cured” or reversed. However, with current Myopia Management treatment methods, the risk of myopia progression can be reduced, and the rate of myopia progression slowed.
The benefit of initiating Myopia Management is reducing the amount of myopia a child would have developed if nothing were done.
The World Health Organization has indicated that a myopic prescription of -5.00D or higher is considered severe myopia. Severe myopic eyes are at a dramatically greater risk for myopia related ocular diseases.
If by employing the various Myopic Management Treatment methods, a child’s myopia can be kept below -5.00D, the risk of these related ocular diseases can be dramatically reduced.
Treatment should continued as long as myopia progression occurs, and can be stopped once myopia is stable for 2 years or more.
Candidates for Myopia Management Treatment
It is recommended that Myopia Management Treatment methods be initiated as soon as a child has developed -0.50D of myopia. The different treatment options each have different criteria that make a child a better candidate for one treatment option or another. These differences will be discussed during a Myopia Management evaluation.
Click to see a list of references regarding Myopia Management.