What Is Progressive Myopia?
Drs. Leong, Bui and Yan have a special interest in understanding the causes of nearsightedness or myopia. This is an eye condition where the eyes have problems seeing farther distances, and it gradually worsens over time so a person feels dependent on wearing glasses full time. The incidence of progressive myopia is increasing. Current prevalence of myopia is 30%, and by 2050, myopia is projected to affect half of the world’s population!
This condition can be so aggressive that for some, each time they take their child to the eye doctor for a vision checkup, their prescription seems to deteriorate. Not only is there a financial burden and inconvenience associated with having to replace eyeglasses on a regular basis, but high myopia (especially beyond -6.00 D) is a risk factor for many eye diseases later in life such as retinal detachment, early onset cataracts, glaucoma and macular degeneration.
What Causes Progressive Myopia?
Myopia is a refractive error that happens when the eye focuses incoming light in front of the retina, rather than directly on it, resulting in blurred distance vision. There is unlikely a single exact cause of progressive myopia. Current research indicates that a combination of environmental and genetic factors trigger the condition. Risk factors include being Asian, female, living in an urban area with significant near work, and not previously breast fed. In Asia extensive research was done for children to spend 1 additional hour outdoors per week, reducing myopia by 14 percent. The theory involves blur in the peripheral vision caused by eye focusing fatigue. This apparently sends a signal to the brain to increase the length of the eye ball, hence increasing nearsightedness.
Family history of nearsightedness is a contributing factor. Additionally, spending a lot of time indoors may play a role in myopia development, as studies show that children who spend more time outside have less incidence of myopia. Lastly, near point stress, which can be caused from looking at a near object for an extended period of time, can prompt the eye to grow longer and result in myopia. Several eye doctors recommend following the 20-20-20 rule when using digital devices (stopping every 20 minutes to look 20 feet away for 20 seconds) to reduce near point stress.
What Can Be Done To Prevent or Treat Myopia?
There are several treatments that have been shown to slow the progression of myopia.
Also known as corneal reshaping, this treatment uses rigid gas permeable contact lenses that are worn while the patient sleeps to reshape the cornea, which is the clear, front part of the eye. During the day, the patient is usually able to see clearly, glasses-free. In addition to allowing glasses-free vision during the day, this treatment has been shown to reduce the progression of myopia in many children.
Distance Center Multifocal Contact Lenses:
This treatment uses distance center (which means the area for seeing at a distance is in the center of the lens) multifocal soft contact lenses to provide clear vision and slow the progression of myopia. The lenses are worn as normal contact lenses during the day.
Low dose atropine drops are a daily-use prescription eye drop that has been shown to reduce myopia progression. It can be used alone or in combination with ortho-k or multifocal contact lenses.
Additional Myopia Treatments:
In Canada, ZeissTM MyoVision glasses that have an innovative lens curvature design are available to help reduce the rate of myopia progression. Additionally some doctors in Canada offer Coopervision MiSight® lenses, which are 1-day contact lenses that are worn during the daytime. These contacts have a multifocal lens design with distance centre and near surround that is specifically designed for children.
Myopia & Your Child
If your child’s vision keeps getting worse, it's more than an annoyance - it can be a serious risk factor for their eye health and vision in the future. The best strategy for myopia control depends on the child and the severity of the case, and requires consultation with an experienced eye doctor in order to determine the best solution. Drs. Leong, Bui and Yan can further discuss which treatment option is best for your child's myopia control. Alberta Health Care covers the cost of eye exams for children up to age 18 years of age. Make your child's vision a priority; schedule an eye exam to ensure stable vision and healthy eyes.