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When myopia becomes a childhood epidemic

  Kara is always the last. When school was over, the other children ran to their parents who were waiting at the school gate, but Carla stood on the playground, waiting for her mother to come to her. Whether it is writing or calculating, this eight-year-old girl is extremely slow. Her mother said she was “a girl who is always dreaming” and worried. What the hell happened to Kara? Does she have a learning disability or psychological problem?
  Later, an ophthalmologist found the crux of everything: Carla was nearsighted. After putting on the glasses, she was no longer always the last to leave school, and her academic performance improved.
| Rising Myopia Rate |

  Statistics show that one out of every five people in the world is short-sighted, and the number of short-sighted children and adolescents is also increasing. A 2015 survey found that 23 per cent of British children aged 12 to 13 were shortsighted, up from around 10 per cent in the 1960s. In Europe, the myopia rate among 25- to 29-year-olds is 47%. The myopia rate among German teenagers and young people in their 20s is 35%. In Asia, myopia is a very serious problem. According to epidemiological studies, the myopia rate of 19-year-olds in South Korea is as high as 96.5%. The figures for the rest of the world, while not quite as horrific, are troubling enough.
  In addition to genetic factors, close eye use is a well-established risk factor for myopia. If the eyes have to look close for a long time, and the lighting conditions are not good, it will cause too much stimulation to the visual center in the brain, causing the eye axis to continue to grow and lengthen, so that the curved surface of the cornea and lens can no longer provide accurate images. projected onto the retina at the back of the eye. Reading is a classic example of close eye use. Proximity reading is a major stimulator of axial growth in people in Western countries, and it is also the main reason why myopia has become an epidemic in some Asian countries. In Asia, many children in the first grade have begun to study hard indoors for a long time, hoping to change their fate through education. In addition to paper-based reading, the use of computers, tablets and smartphones can also lead to excessive focus on small print at close range, thereby aggravating the myopia problem of the younger generation.
  According to the prediction of the Huabaien Vision Research Center in Sydney, Australia: the number of myopic people in the world is currently 1.5 billion, and by 2050, it will reach 5 billion, of which the number of patients with high myopia will reach nearly 1 billion. This can impose a huge burden on the health system because people with myopia are more likely to have other eye diseases than people with normal vision, people with high myopia are more likely to have severe vision impairment and even blindness, and are more likely to develop macular degeneration, cataracts or glaucoma , the risk of retinal detachment is also greater.
| Miracle of OK Mirror |

  In order to prevent the spread of myopia epidemic, the medical community has developed a special contact lens – “orthokeratology lens” (often abbreviated as “OK lens”). These rigid breathable contact lenses are not worn during the day, but at night. It adopts the so-called “reverse geometry” shape design, which temporarily reduces the degree of myopia in children and adolescents by changing the geometric shape of the cornea, and controls the growth of the eye axis, so as to achieve the purpose of slowing down the development of myopia.
  Much of the research on OK lenses has been done in East Asia, where myopia is particularly high. In 2015, scientists in Australia conducted a study of East Asians between the ages of 8 and 16. Unlike normal clinical studies, this study did not have a control group, but had a control, which was the subject’s other eye. Myopic subjects with a diopter between -1.0D and -4.0D wore OK lenses in one eye for half a year at night and no lenses during the day, while the other eye wore traditional oxygen-permeable contact lenses during the day and no lenses at night. After six months, subjects discontinued the OK lenses for two to three weeks, then the treatment of the two eyes was switched, and the eye with the OK lens was started to wear normal lenses to correct vision, and the other eye was started to wear the OK lens.
  The study took a year. For the first six months, the axis of the eye with the OK lens grew more slowly. In the next six months, this slowing of growth also occurred in the other eye treated with the OK lens. After the first six months of OK lens treatment, subjects’ myopic diopter decreased from an average of -2.43D to -0.11D. After exchange therapy, the eye that received the OK lens in the second study period also had a reduction in diopter from an average of -2.60D to -0.33D.
  However, it is worth noting that for eyes treated with OK mirrors in the first half of the year, the degree of myopia increased again after the treatment was exchanged in the second half of the year. Scientists say the study is too short and will take years to determine how long a child or teen needs to wear the orthokeratology lens for stable vision. That is, after the treatment ends, the eye axis will not grow faster again.
  In 2014, a two-year study in China looked at the use of OK lenses in children with high myopia and found that their axial growth was only 0.18 mm, compared with 0.34 mm in the control group.
  Ophthalmologists are not only offering OK lens therapy to minors, but are also recommending it to an increasing number of adults. Mild myopic patients with a diopter of -1.0D to -3.0D can change most of their diopters to 0D after wearing OK lenses overnight. Changes in the cornea create this little miracle. During the day, the effectiveness of the OK lens will gradually wear off: people who don’t need to wear glasses when they go to work in the morning are short-sighted again at night.
  In addition, it is not known whether there is a risk in wearing glasses at night. Cornea specialist Thomas Reinhardt of the University Eye Hospital in Freiburg, Germany, therefore does not recommend wearing OK lenses. He believes that people who wear OK glasses during sleep have reduced metabolism of the surface of the eyeball, which may cause mild infection. That’s a dire risk with ordinary contact lenses worn during the day, and can be exacerbated at night when people don’t blink during sleep and don’t get enough fresh tears to cover their eyeballs.
  Reinhardt believes that there is no empirical analysis on the risks of orthokeratology lenses, but the frequent cases of eye infections during OK lens treatment are enough to cause concern.
| Outdoor activities more than two hours |

  Kara’s mother is not going to let her daughter wear OK glasses. Framed glasses are enough, she believes, and Carla should play outdoors more often, as research has shown that outdoor activity slows the progression of myopia.
  Natural light is a key factor in slowing or preventing the development of myopia in macaques, a study suggests. If the test animals did not live entirely in artificial lighting in early childhood, but were active in natural light for three hours a day, they were able to effectively control myopia development, even if they were exposed to other conditions that might promote myopia development. This was also confirmed by researchers at Sun Yat-sen University in China. They had elementary school students study in a classroom made of light-transmitting plastic to simulate an outdoor environment and ensure similar light levels. The results showed that the outdoor environment can significantly slow down the progression of myopia.
  ”We can conclude from 19 studies involving more than 20,000 people that children who spend more than two hours outdoors have a one-third lower risk of myopia than children who spend less than an hour outdoors.” “Light is a key factor in protecting eyesight,” says Dr. Wolf Lagretz from the University Eye Hospital in Freiburg. “On a sunny day, the light intensity is only 300 to 500 lux indoors and 100,000 lux outdoors. Even on cloudy days. 20,000 lux of sunlight outside.” Whether certain types of natural light have additional myopia-reducing effects—such as seeing whether green is better for vision—is inconclusive, as does exercise. Although children who were active outdoors exercised more than children who sat indoors, it is unknown whether this is an independent factor that inhibits the development of myopia.

| Low Concentration Atropine and “Growth” Lenses |

  In many places, including Germany, it is difficult for the vast majority of parents of myopic students to keep their children outdoors for two or three hours a day. So, in addition to wearing OK glasses, what other treatments are there?
  ”There is a study in Asia showing that low concentrations of atropine eye drops can prevent the development of myopia,” Ragretz said. “For this, we need atropine eye drops at a concentration of 0.01%, which is not yet approved. Commercial sales. This kind of eye drops is usually specially produced by some pharmacies according to the prescription instructions.” Low concentrations of atropine can prevent children from dilated pupils and are sensitive to light, and can maintain children’s ability to adjust the eyes, that is, the eyes can see far away. close conversion capability. However, the use of atropine to delay myopia has always been an off-label drug, not licensed, and there is a lack of long-term large-scale observational studies of children receiving this eye drop.
  Another option is the ZEISS “Growth”, a lens specially made for short-sighted children. What’s special about this lens is that it allows light to be imaged not only at the center of the retina, but also at its edges, which is not possible with conventional lenses. “Growth” lenses are not available in Germany, although they are produced by the German company Zeiss. According to the information given by the company, it is tailored for the East and Southeast Asian markets. There, the lens’ effect in slowing the progression of myopia was confirmed in a study of 210 children aged 6 to 12, but it was not sold in Europe or the United States.

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