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Early onset of myopia is associated with high myopia later in life, and high myopia is associated with many sight-threatening conditions. The Chinese University of Hong Kong (CUHK)’s Faculty of Medicine (CU Medicine) conducted a randomised, placebo-controlled, double-masked trial of low-concentration atropine eyedrops to evaluate their effectiveness in preventing myopia. Results show that among children aged four to nine years without myopia, compared with placebo, nightly use of low-concentration 0.05% atropine eyedrops resulted in a significant reduction in the incidence of myopia over two years, from 53.0% to 28.4% (a relative reduction of 46.4%). This is the first study in the world to prove that low-concentration atropine eyedrops can prevent the onset of myopia. Details of the study have been published in the renowned medical publication The Journal of the American Medical Association (JAMA).

Myopia is a worldwide public health threat, with the highest prevalence in East Asia

Myopia is a worldwide public health threat with increasing prevalence across many regions in recent decades. A study published by the American Academy of Ophthalmology predicted that approximately half of the world’s population will be myopic by 2050, with the highest prevalence in East Asia, the region that includes Hong Kong. Professor Clement Tham Chee-yung, Chairman and S. H. Ho Professor of Ophthalmology and Visual Sciences from the Department of Ophthalmology and Visual Sciences at CU Medicine, remarked, “The increasing prevalence of myopia concerns many countries. For example, the Central Government in the Mainland aims to set up a mechanism covering all counties and districts across the country by the end of 2025 that can track myopia rates among youngsters and detect the factors that influence them. In Hong Kong, we have noticed that the COVID-19 pandemic has triggered a myopia boom in school children due to school closure and social distancing measures. Strategies to prevent myopia onset and to reduce its progression have become paramount.”

Early onset of myopia leads to an increased risk of high myopia and many sight-threatening conditions

Myopic individuals have a higher risk of sight-threatening complications that lead to poor vision and even blindness. “Myopia can be caused by excessive elongation of the eyeball,” said Professor Calvin Pang Chi-pui, S. H. Ho Research Professor of Visual Sciences from the Department of Ophthalmology and Visual Sciences at CU Medicine and Director of the Shantou University / The Chinese University of Hong Kong Joint Shantou International Eye Centre. “This disease is irreversible once it has developed and the earlier its onset, the greater the likelihood of high myopia occurring later in life. Glaucoma, macular degeneration, retinal detachment and cataracts are all complications of high myopia. The eyeball elongation problem cannot be corrected by wearing glasses or having laser refractive surgery, and thus the risk of complications cannot be reduced. Therefore, prevention or delay of myopia onset should be given top priority.”

Additional myopia prevention strategies are warranted for high-risk children

Studies have confirmed that the only way to prevent myopia and delay the myopia onset was to increase the time for outdoor activities. Dr Zhang Xiujuan, Research Assistant Professor from the Department of Ophthalmology and Visual Sciences at CU Medicine, said, “In a previous trial conducted in Mainland China, increasing outdoor class time by 40 minutes daily was proven to reduce the three-year cumulative incidence of myopia in children by 23%. Although encouraging children to spend more time outdoors is an effective approach, additional strategies are warranted, especially for children at high risk of developing myopia. Children whose parents are both myopic, have 12 times the risk of developing myopia compared to those whose parents are nonmyopic.”

Low-concentration atropine eyedrops can prevent myopia in children

The CU Medicine research team recruited 474 nonmyopic children aged four to nine years at the CUHK Eye Centre to join the randomised, placebo-controlled, double-masked “Low-Concentration Atropine for Myopia Prevention (LAMP2)” trial from 2017 to 2020. The participants had at least one parent who is myopic. They were randomly assigned to the 0.05% atropine group, the 0.01% atropine group, or the placebo group and had eyedrops applied once nightly in both eyes for two years.

Results showed that the 0.05% atropine group had a significantly lower two-year cumulative incidence of myopia and a lower percentage of participants with fast myopic shift, compared with the placebo group (see details in Table 1).

Dr Jason Yam Cheuk-sing, Principal Investigator of the LAMP2 Study, Associate Professor from the Department of Ophthalmology and Visual Sciences, CU Medicine and Director of the CUHK Jockey Club Myopia Prevention Programme, stated, “Our previous LAMP1 study proved that low-concentration atropine eyedrops can reduce myopia progression and a 0.05% concentration appeared to achieve the best balance between maximising efficacy and minimising side effects. The current LAMP2 study has further shown their potential in preventing myopia onset. As our younger generation becomes more reliant on digital devices and we are facing a surge in myopia in the future, our findings suggest low-concentration atropine eyedrops is an effective preventive strategy for myopia onset among high-risk children and reduce their risk of suffering from sight-threatening diseases.” 

The team plans to launch a LAMP3 study to investigate the efficacy and safety of combining atropine eyedrops with red light therapy. Interested individuals can contact the research team by WhatsApp (91371925) or email (childreneye@cuhk.edu.hk).