Myopia, also called nearsightedness, is on the rise world-wide. What was once considered only a slight hassle easily fixed by glasses, is now a tremendous cause for concern on the public health stage. Currently, 33% of the world’s population is myopic, but this number is exponentially increasing. In fact, by 2050, over 50% of the global population, or 5 billion people are predicted to be myopic.1 This rise is particularly alarming in children, in which myopia has even doubled or tripled in certain parts of the world.
This staggering upswing is thought to be secondary to a multitude of risk factors, including the increased time children spend on screens and doing near work activities, and the decreasing amount of time they spend outdoors. Treatment strategies are now available to slow or even delay the onset of myopia, but they must be instituted by the appropriate age to be successful. Educating parents that their child’s worsening myopia includes possible vision-threatening outcomes for children later in life is the first step. Second is for parents to understand the potential for prevention of nearsightedness and myopia management through lifestyle modification and therapeutic options. As such, collaboration between pediatricians and eye care providers is essential in delivering this vision saving care in a timely fashion.
Anatomy of myopia
Many parents simply consider nearsightedness as blurred vision for distance objects which can be easily corrected with glasses or contact lenses. However, there are significant eye health and vision threatening consequences of myopia. Myopic eyes tend to be longer than eyes that are not nearsighted, causing images to be focused in front of the retina instead of on it. This elongation of the eye results in the retina and sclera being stretched more thinly, typically occurring in people who have prescriptions above -6.00 Diopters. This form of myopia, also called high myopia, degenerative myopia or pathologic myopia, is the fourth most common cause of irreversible blindness in the world. A child with medium to high myopia (-3.00 Diopters to -6.00 Diopters) is 5x more likely to develop cataracts and glaucoma than one who is not.
In retinal detachments, the inner lining of the eye, called the retina, detaches from the underlying surface. Typically, this is because the retina is stretched in myopic individuals, making them more prone to retinal breaks. A mild myope is 21X more likely to develop a retinal detachment, and a high myope 44X more likely to suffer from one. When the retina is detached, it is deprived of oxygen and vision loss can be permanent and severe. It is one of the true emergencies in eye care and requires urgent surgical treatment. Even if treatment is instituted immediately, vision can still be compromised severely and usually does not recover to pre-detachment levels. Myopic patients are also more likely to suffer from retinal detachments when undergoing routine eye surgery such as LASIK and cataract surgery.2
Retinal detachments, myopic maculopathy, cataracts, glaucoma and retinal tears all occur with greater frequency in highly myopic patients. Typically, myopia begins in early childhood and progressively worsens until early adulthood when it stabilizes. Unfortunately, the anatomic changes that result in these eye diseases cannot be reversed once they occur, but they can be prevented by the institution of myopia management strategies when the eye is still developing.
Treatment strategies to slow myopia progression
Clinical research has consistently shown the protective benefit of time spent outdoors on slowing myopia progression in children.3 This effect has been seen in a diverse group of children (Chinese, Australian) and even moderate sunlight, just 11 hours/week, has been found to be sufficient to decrease myopia increases substantially.4 Remarkably, the protective effect of outdoor time is not correlated with level of physical activity, nor does the sunlight need to be direct. Time spent outside during recess and physical education is certainly helpful, but so is indirect light such as kids sitting outside or walking in indirectly sunlit hallways has also shown to be beneficial. Encouraging children to get outdoors more is a great way to delay the onset of myopia, while also reaping the physiologic and psychological benefits as well.
Low-Dose Atropine Eye Drops
Since 2004, low-dose atropine eye drops have been proposed as a method of slowing myopia progression and have gained widespread acceptance in Asia. Atropine dilates the pupil and relaxes the eyes' focusing mechanism.5 Clinical trials indicate that low-dose atropine eye drops can slow myopia progression in children. The eye drops are applied every night and typically maintained for a minimum of 2 years,6 though many ophthalmologists will continue treatment until myopia stabilizes around ages 16-19 years old, since myopia tends to progress until early adulthood.
Contact lenses offer another treatment option for children who are mature enough to handle the responsibilities of contacts. Soft multifocal or dual-focus contact lenses—typically used to improve near vision in people over 40—have been shown to correct myopic vision in children while simultaneously slowing myopia progression by decreasing eye growth.
Orthokeratology (ortho-K) is a rigid gas permeable contact lens worn overnight to temporarily reshape the cornea and provide clear vision throughout the day without wearing any vision correction. These contact lenses have been shown to slow myopia progression and eye growth.
Myopia control glasses are an option in Canada and Europe for children who are not contact lens-ready. These glasses differ from standard single vision lenses by incorporating segments of defocus zones to slow the progression of myopia, along with focus zones which allow for clear vision.
Awareness & Education Opportunities
With the current evidence-based treatment options available, we now have the chance to begin advocating for and instituting therapeutic measures that could slow or even delay the onset of myopia in children, as opposed to simply measuring its inexorable worsening every year. If these treatment strategies are implemented early, the risk of potential visual loss from high myopia can be lowered. The potential benefits of myopia control outweigh the risks and it is an important point of discussion for parents of myopic children.7
Pediatricians are critical in bringing awareness of these new treatment options for myopia to parents. Many parents may be concerned about strategies that were not available to them when they were young. Pediatricians can:
As a pediatric ophthalmologist, I have witnessed firsthand the increasing prevalence of myopia in my practice. We have the unique opportunity now to help create lasting impact on a child’s lifelong vision by preventing myopia progression and its devastating ocular consequences. Actions and interventions should be started early, and thoughtful discussions with parents regarding their options from pediatricians, family practitioners, ophthalmologists and optometrists are essential for parents to make informed decisions for their children. Informed consent requires clarity, and clear options require open communication. Parents, often confused by the implications of the diagnosis of myopia and overwhelmed by medical acronyms and jargon, need unbiased, transparent guidance. We, as a united front of healthcare professionals, must bridge this information gap, ensuring parents understand the potential long-term consequences of unchecked myopia and the spectrum of preventative options available.