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Myopia is an epidemic in children...particularly in urban Asia, experts crunch the numbers
Uncovering the Myopia Epidemic in Children
by Brooke Herron
On the second day of AAO 2020 Virtual, experts convened to discuss the epidemic of myopia among children during a symposium titled, “Preventing Myopia Progression in the Pediatric Patient,” co-sponsored by the American Association of Pediatric Ophthalmology and Strabismus (AAPOS).
The genetic factor
“It’s important to note that 4.8 billion people, or about half of the world’s population, is expected to be affected by myopia by 2050,” said Dr. Terri Young. The epidemic is particularly prevalent in urban Asia, where up to 95% of 20-yearolds in cities such as Seoul, Hong Kong and Singapore have this refractive error — a trend that’s expected to occur in other regions, she continued.
So, what are the causes? Dr. Young says it’s a complex interplay between lifestyle and genetic factors.
Recent research has identified many genetic variants for refractive errors, myopia and axial length, she shared, highlighting a point from the CREAM study: “What was interesting was that most of the genes identified that were associated with myopia were related to rod and cone synaptic neurotransmission, some anterior segment morphology and some angiogenesis pathways. So, we’re thinking that some of these light sensitive genes might be more involved in myopic development than we realized before.
“If you have a child with high myopia, and it’s not connected to an identifiable tissue disorder, have them undergo electrophysiology testing — we’re finding that they may have some sort of retinal degenerative-type issue,” shared Dr. Young.
Near work, outdoor time and myopia
“The eye is not meant to focus on near [distance] for an extended amount of time,” said Dr. Paul Rychwalski. “There is constant ciliary muscle contraction required to hold a near object in focus.”
And lifestyle factors, like near work, have been blamed for myopia progression. “There have been many studies recently looking at near work and myopia, however most of these are quite inconclusive,” he said, adding the results for screen time and myopia have also been mixed. “Further studies are needed that look at objective measurements of screen time, but also look at some of the other factors such as illumination, distance, and angle of the screen from the eyes, and also the decreased outside activity that may all be intertwined and leading to more myopic progression.”
Adding to the importance of outdoor time was Dr. Noha Ekdawi: “There’s been several studies that have shown that when children spend sufficient time outdoors (more than two hours per day) their risk of myopia was reduced, even when they had two myopic parents and continued to perform near work,” she shared.
Dr. Amy Hutchinson covered two types of contact lenses — multifocal and overnight orthokeratology (OrthoK) lenses — to prevent myopia progression in children.
... and that mechanism is to eliminate peripheral hyperopic defocus and induce peripheral myopic defocus.
“Multifocal lenses and overnight orthokeratology lenses can provide a clinically meaningful slowing in myopic progression,” said Dr. Hutchinson, adding that further research is needed on the timing and duration of treatment.
Another potential solution to prevent myopia progression is low dose atropine.
“Low dose atropine is safe and effective at slowing myopic progression in children, and .05% may be more effective than .01%,” said Dr. Cynthia Beauchamp, who shared clinical data, as well as her protocol for using atropine.
Currently used off-label, she noted that FDA trials are underway for commercial distribution which will increase access, ease of use for families and reduce personal expense.
