Myopia prevention — from evidence to practice
The worldwide prevalence of myopia is expected to increase from 1.4 billion people at present to 4.7 billion people by 2050. More alarming is the suggestion from a recent meta-analysis that the prevalence of high myopia will increase by more than 300% to approximately 938 million people by 2050. Myopic retinopathy has become a leading cause of blindness worldwide.
Previous schools of thought attributed the cause of myopia to genetics, although it is clear now that this cannot explain the increasing prevalence to epidemic levels, particularly in East Asian populations, over the past decades. We are increasingly recognizing the impact of environmental and behavioral contributions to myopia development. Risk factors include increased time spent reading or studying and, more recently, reduced outdoor time and perhaps light exposure. The onset and development of myopia are explained in part by a genetic predisposition and in part by susceptibility to environmental risk factors.
At present, delaying the onset and slowing the progression of myopia appear to be the best ways to limit further deterioration to high myopia in high prevalence countries and populations. Data from observational studies and randomized trials have provided evidence for such strategies, but the bigger challenge lies in translating these findings into “best practice” patterns for schools as well as the community of ophthalmologists and optometrists.
Asia-Pacific Myopia Society
A group of leading myopia researchers throughout the Asia-Pacific region established the Asia-Pacific Myopia Society (APMS) at the recent 2016 APAO conference in Taipei. APMS aims to promote research, education and academic exchange and disseminate best practice information for the prevention and treatment of myopia with its associated complications. The APMS council led a symposium and panel discussion on myopia at the 2016 APAO conference, with invited speakers covering topics ranging from epidemiology to evidence-based management and prevention strategies for high myopia. The society advocates for a concerted effort between governments and eye care providers to limit the overall prevalence progression of myopia and to emphasize the under-recognized dangers of high myopia.
The prevention and management of myopia should be holistic, from involving schools and family to developing effective treatment in clinical settings. Given that high myopia is an irreversible condition, interventions to prevent the progression to high myopia are among the highest priorities in myopia clinical management. As indicated in the cover story of this issue of OSN APAO Edition, optical strategies (such as orthokeratology and specially designed contact lenses) as well as pharmacological agents (such as low-dose atropine eye drops) may provide effective treatment options. However, these treatments are often for the long term and require good compliance until the child reaches adulthood. To reduce the risk of developing high myopia in adulthood and to minimize the risk of side effects, it is important to identify children who are at greatest risk of developing high myopia as early as possible. This way, they can be treated when their degree of myopia is mild to achieve the full potential of the progression prevention. Currently this relies heavily on clinical acumen and the experience of individual clinicians and is highly subjective. A free-to-access online risk assessment tool, based on a prediction algorithm and 10 years of annual refraction data from the Guangzhou Twin Eye Study, will become available by the end of this year to hopefully assist clinicians in triaging myopic children. By inputting simple parameters, the tool will be able to provide estimates for patients’ myopia trajectory, probability of developing high myopia and even the diopters of refraction at adulthood.
With an exponentially increasing worldwide prevalence, myopia has become a major health issue that deserves a careful, considered and holistic approach, including practical health policies that encourage prevention strategies such as outdoor light exposure, as well as improved risk-stratified management strategies for myopia in children.
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For more information:
Dennis S.C. Lam, MD, FRCOphth, can be reached at State Key Laboratory in Ophthalmology, Sun Yat-Yen University, 54 South Xianlie Road, Guangzhou 510060, People’s Republic of China; email: firstname.lastname@example.org.
Disclosure: The authors report no relevant financial disclosures.