What is Myopia?
Myopia, or short-sightedness, occurs when light entering the eye is focused in front of the retina rather than directly on the retina. This causes blurred distance vision. The more myopia you have, the closer you have to be to see an object clearly.
You are more likely to be myopic if you have at least one myopic parent however up tp 60% of patients with high myopia do not have a family history of the condition.
Myopia progresses most rapidly in the early stages, so starting treatment as early as possible will give the best opportunity for a positive outcome. In the majority of cases myopia progression will naturally stop in their mid-twenties.
Why do we want to slow myopia progression?
Unfortunately, being myopic does not just mean that you are reliant on glasses or contact lenses to see clearly in the distance. People who are myopic are more at risk of developing conditions like glaucoma, cataract and retinal complications later in life.
The greater the level of myopia, the higher the risk of the associated eye conditions. Because of this we strive to reduce the amount of myopic progression in our patients.
How can you slow myopia progression?
The progression of myopia is multifunctional and not fully understood. This means that the benefits of myopia control are measures over a population group and will vary between individuals. At present, there are no treatments to stop the progression of myopia completely, however, there are number of options that can be beneficial in slowing the progression of short-sightedness.
Spending more time outdoors has been lined with lower incident of myopia and reduced myopic progression. The majority of the lens based treatment work on the peripheral defocus theory. Traditional glasses and contact lenses correct myopia by focusing light directly on the central retina to give a clear image. However, due to the limitations of the eye optics, there is a hyperopic defocus on the peripheral retina (the light is focused behind the retina). This peripheral hyperopic defocus is believed to be a signal for the eye to continue growing, leading to more short sightedness.
Myovision spectacle lenses and myopia control contact lenses are adapted to induce a myopic defocus on the peripheral retina (the light is focused slightly in front of the retina), while maintaining a clear central focus. This reduces the signal for eye growth.
An emerging treatment for myopia progression involves the use of low concentration atropine drops. The exact method of action is unknown at this point, but it is believed to be linked with inhibition of thinning and stretching of eye tissues.
You may have heard about a form of myopia control which involves under-correcting myopia, giving weaker glasses than what is necessary for clear vision. This does not work, and in fact has been found to increase the progression of myopia. Because of this, even if you decide not to pursue myopia control treatment for your child, it is important that they continue to have regular eye examinations and updates to their glasses or contact lenses as required.
What options are suitable for my child?
Myopic children tend to spend 1-2 hours less outdoors per week than non-myopic children. Spending more time outdoors has been found to be protective against myopia progression.
There is no proven link between near work and myopia, through children who work at close distances and spend excessive time focused on reading may be at particular risk of progression.
Myopia control glasses
Special spectacle lenses have been specially designed to help reduce progression of myopia. This type of lens is particularly helpful in children who have one or more parents with myopia, or who have a moderate amount of astigmatism. Studies including children up to the age of 12 have shown up to 60% reduction in myopia progression if their parents are short sighted.
This is a good option for younger children or those who are not suitable for contact leans wear, through it is not as effective as other forms of myopia control.
Progressive and bifocal lenses have been traditionally used to help control the progression of myopia; however, the studies into their effectiveness have been contradictory. Recently, there have come available Miyosmart lenses that have been proven to reduce myopia by up to 60%.
Soft Contact lenses
Contact lenses are a single wear disposable contact lens which can reduce myopia progression by up to 80%. The contact lenses are worn during the day and are removed each night. Because they are a daily disposable lens, there is no need to clean the lens, as you use a fresh lens every day. This reduces the risk of infection when compared with reusable lenses.
These lenses are not available in high prescriptions, or for patients with significant astigmatic correction.