Myopia: Coming Epidemic

Article written by Zac Unger

When Sylvia Chin noticed that her son Jared was squinting to see things at a distance, she knew exactly what was going on. Both Chin and her husband are myopic, and even when Jared was a toddler, Chin’s own optometrist told her, “you can’t beat your genes,” and that she would need to monitor her kids closely. Jared’s first exam, during kindergarten, indicated that he had 20/20 vision. But things began to slide from there. On his second visit a year later, Jared’s nearsightedness was measured at a fairly mild -1.00 diopter. “But then he went from -1.00 to -2.00 and then from -2.00 to -2.75 the year after,” Chin recalls.

All this felt unsettlingly familiar. As a five year old, Sylvia Chin was one of the first kids in her Hong Kong classroom to wear glasses, and she has a distinct, uncomfortable memory of all the students and teachers turning to stare at her when she first wore them to school. Her myopia progressed, so much so that just last year she was forced to undergo surgery for “oil droplet” cataracts, a procedure usually performed on people decades her senior. Needless to say, Chin did not want her son to suffer the same lifelong vision problems that she’s experienced.

To say that the Chins are not alone is to vastly understate the scope of the myopia problem in the world today. Even calling it an epidemic might be too mild, and yet the enormity of the problem has largely gone unremarked upon by the general public, especially in the United States. “When I started out in the field and I would give a talk,” says Dr. Maria Liu, Chief of Berkeley Optometry’s Myopia Control Clinic, “I needed to start out by convincing other optometrists that this was an important problem to study.” When a patient begins becoming myopic, the eye elongates more than normal, so
preventing further physical change is critical. “Once the eye grows to a certain size, we can only slow it down,” says Dr. Liu. “You can’t turn a 24 millimeter eyeball back into a 23, so starting treatment early is key.”

Today, statistics suggest that half the world’s population will be myopic by 2050. In Asia, the numbers are even more staggering. A study in Seoul, South Korea, where all teenage boys undergo medical screening prior to national service, showed that 96.5% of 19 year-olds are myopic. In China, says Dr. Liu, “the prevalence is so high that it’s becoming a problem for military recruitment. People are having premature refractive surgery because they want to become enlisted.” Moreover, early myopia can lead to complications like glaucoma, macular degeneration, and retinal detachment later in life. Dr. Liu says that statistics show that “myopia is now the leading cause of blindness in the world across all ages, ethnicities, and demographics.”

So what’s causing this rapid spike in nearsightedness? Sylvia Chin’s optometrist was partly correct in blaming genetics. “But if it was all genetics, we wouldn’t have this rapidly climbing prevalence,” says Dr. Christine Wildsoet, Professor of Optometry and Vision Science at UC Berkeley. The epidemic has taken root over just a handful of generations, far too quickly to pin on evolutionary mutations. Instead, the problem appears to be strongly associated with “close work,” indoor activities like reading, typing, and long hours in front of screens. “We all know that smart kids are myopic,” Wildsoet says. “In fact, in our own population here [at Berkeley] we have a hard time finding students who are not myopic to use in our studies.” In many Asian countries the average age of onset is during elementary school, and in countries like Singapore, which has a culture of rigidly academic pre-school, it can be even earlier. “The younger we are, the more plastic the eyeballs are,” says Dr. Liu, “and now, even babies are being introduced to electronic games and apps, so we see a very fast progression of myopia.”

Fortunately for Jared Chin and the 650 other patients who are seen every year at the Myopia Control Clinic, Berkeley Optometry is not only one of the world’s leading research institutes but also a top-notch treatment facility. “Myopia is irreversible,” says Dr. Liu. “So we work to achieve a temporary correction and also slow down or prevent further progression.” Think of the eyeball as shaped like a hard-boiled egg, lying on its side as it would if you placed it on a table. As the eye grows accustomed to focusing on near objects, it physically elongates along the horizontal axis. With the physiological proportions askew, light entering the eye focuses too far in front of the retina, causing distant objects to appear blurry even while near objects remain clear. Treatment at the Myopia Control Clinic, therefore, is a process of encouraging the eye to maintain its natural shape, slowing the elongation rate during the high-risk childhood and teen years. “Kids don’t necessarily understand the long term benefit of reducing complications, but they do understand not having to wear glasses,” says Dr. Liu. “Parents understand both the short- and long-term benefits.” The major goal of the clinic is slowing further eyeball growth. “We are essentially trying to prevent or minimize that axial elongation in order to reduce the risk of bad complications in the future,” says Dr. Liu.

There are three main treatment modalities: atropine eye drops, multifocal soft contact lenses for daytime wear, or orthokeratology, also known as ortho-k, which is the use of rigid contact lenses at night only. Importantly, all three of these treatments have been shown to slow eye elongation in young myopes. For the initial consultation, every patient is seen by Dr. Liu or her colleague, Dr. Sarah Kochik, who completed both her Doctor of Optometry degree and a pediatrics residency at Berkeley Optometry. (As if that wasn’t enough time at Cal, Kochik also did her undergraduate work at Berkeley and is currently pursuing a PhD here.) Dr. Kochik makes a point to discuss the pros and cons of all three options with patients and their parents. “We don’t have strong evidence to suggest that one is much better,” she says. Whatever actually works for each patient is what’s better.” No matter the treatment, getting to a patient early is critical. Childhood is a high-risk period where the eyeball is subject to rapid elongation, so the clinicians work to ensure that a patient’s prescription stays as stable as possible for the long haul.

For twelve-year-old Michael Tan, who had myopia in only one eye, ortho-k was the right choice. He and his parents both liked the idea of only having to wear the contact lenses at night. “Ortho-k works by temporarily changing the curvature of the cornea,” Dr. Liu says. “And the cornea has a very good memory, so during the daytime the patient will have clear vision without any lenses.” To keep the eye “trained” the patient must wear the lenses every night, at least until young adulthood when the eye becomes less prone to rapid change.

For Michael the results were dramatic. “It was incredibly quick,” says his father, Thomas. “Within a week he could basically see with perfect parity between both eyes during the day.” Jared Chin experienced similar results, quickly ditching the glasses he had worn on the basketball court and the corrective goggles he’d worn for swim practice. Incredibly, dramatic effects like this are the norm, says Dr. Liu. “For overnight ortho-k we should see fifty percent of the corrective effect after one night and the full effect after seven to ten days.”

Which is not to say that the process works for everyone or that it is without difficulty. Learning proper lens placement technique—not to mention care and cleaning—can be challenging for an adult, let alone the average school-age kid who might forget to brush his teeth every night. “It was always easy when he was with the doctor in the office,” recalls Thomas Tan. “But when we got home, my god, it was such a struggle.” Fortunately, the doctors at the Myopia Control Clinic are well practiced at helping kids adjust. “Some kids get it right away and some kids have to come back multiple times,” says Dr. Liu. Throughout the process, the emphasis is on the patient’s ability to effectively comply with treatment. “Parents ask me at what age their kid can get ortho-k,” Dr. Liu continues. “But it’s about the maturity, not the age. That can happen at six or it might not be the case with someone who is eighteen.” Patients must be self-motivated, independent, and vigilant enough to monitor their own care and report any problems that arise. “What I appreciate about Dr. Liu,” remembers Sylvia Chin, “was the way she talked directly to Jared instead of just to me. He got the chance to make the decision for himself rather than having it be forced on him.” As a result, many parents report that the experience of maintaining an ortho-k regimen actually helps their kids take more responsibility in other areas of their lives.

As the incidence of myopia continues to rise, the Myopia Control Clinic is poised to lead the way both in terms of treatment and with prevention-based research. The collaboration between researchers and clinicians is essential, and each side of the equation prods the other towards improved patient outcomes. “I like to describe our clinic as systematic, comprehensive, and cutting edge,” says Dr. Liu. “We understand myopia at a levelfar beyond your average practitioner.” While patients respond enthusiastically to improved eyesight, the clinicians understand that the long-term benefits of treatment are even more important. “Once your prescription is at a minus-three,” explains Dr. Liu, “the risk of retinal detachment is ten times higher than for someone who is not nearsighted.” Taking off the glasses is nice, but reducing the incidence of major complications—even blindness—is absolutely imperative.

One factor that fascinates clinicians and researchers alike is the strong evidence that suggests that time outdoors has a protective effect on young children. “We don’t have an exact dose-response level for how much outdoor time you need,” says Dr. Wildsoet, “but this is a very interesting area for further study.” During China’s cultural revolution, for example, the prevalence of myopia nosedived as intellectuals were sent out into the fields. When they came back to the cities and resumed an indoor lifestyle, myopia took an upward turn. Similarly, kids in one study who were encouraged to take recess
outside were less likely to become myopic; when the classroom doors were locked shut so kids couldn’t sneak back in, the prevalence declined still further. “Once a child becomes nearsighted,” says Dr. Liu, “they tend to become a lot more indoorsy and so you’ve got a really bad downward cycle.”

Because of this, the doctors at Berkeley Optometry emphasize early consultation and early treatment, stressing lifestyle changes and proper visual hygiene. This necessitates a high degree of individual attention given to each patient, which the clinicians and students enthusiastically provide. “I got into medicine because I wanted to spend a lot of time with people, which is actually pretty rare now,” says Dr. Kochik. “But here I really get to know my patients on a personal level.” “There’s no such thing as nine to five when you’re working with kids,” says Dr. Liu. “You must have timely triage for any problems. Other schools ask me for tips on setting up a clinic like this and I tell them that they have to have weekend clinics like we do, and they tell me that their doctors would never do that.” Significantly, the Clinic’s fee structure is such that patients pay for an entire year, all-inclusive, no matter how many visits they end up using. “When you’re fitting kids with contacts, you need to be pretty conservative,” says Dr. Kochik. “We never want finances to be a reason for not bringing a kid in for a consultation.”

While being a little nearsighted might seem like no big deal—just put on a pair of glasses, right?—the longterm effects on kids can be profound. Late-life complications like glaucoma aside, just being myopic changes the way kids interact with their peers and their environment. “He can be more aggressive on the basketball court,” says Sylvia Chin about her son. “He can wear cool sunglasses. He doesn’t have to deal with the stereotypes of wearing thick glasses. I feel like Jared is more free now.”

And for the clinicians at Berkeley Optometry, there’s nothing more satisfying than watching a patient gain better eyesight literally overnight. “It’s not just about giving a patient good vision,” says Dr. Liu. “It’s about transforming them into a different, more confident person.”

Article originally published in the Berkeley Optometry Magazine.